It is possible that misting could cause disease issues, so you should be mindful of that. With dust and spider mites, I do take the chance and mist, and also provide good airflow.

When providing light indoors over winter, one pecularity to mention about citrus is that if you put sunlight on the leaves, make sure the pot also gets direct sun. If you heat up the leaves but not the soil, you could lose leaves. Since you are using a small pot I assume it will sit on a sill and not under it.

" If you heat up the leaves but not the soil, you could lose leaves." Seriously? Now that's something else to think about....

In winter the windowsill becomes an interesting place. It gets sunlight but at the same time there's cold seeping in through the glass (especially when it's -15C outside.. or less).. and there's dry heat coming up from a radiator below the windowsill. I'm beginning to think I may have problems, and not only with the citrus..

My goodness! Sorry Denise - not long ago you were chiding me personally, as well as for my reliance on science instead of opinion or conjecture when discussing things like fertilizer/fertilizing, container media, and several other topics. When I read what you offered above, I was amazed at the amount of misinformation packed into only a few paragraphs, information that if treated as fact, has the potential to diminish the growing experience of others. I've always based my decision to respond to misinformation on whether or not it has the potential to cause others problems, so I'm not singling you out. You've reminded me several times that you have no interest in reading anything scientific, but perhaps others are interested. When someone is operating at beyond the limits of their knowledge and providing information that's so demonstrably wrong, they should expect feedback from others who do know and respect their limitations.

You offered: I have been growing citrus trees for over 20 years and some of the information given above, I do not agree with and go on to say:

I have never heard of intentionally removing leaves from a tree when
transitioning from inside to outside. I do it with great regularity.

Defoliation and partial/selective defoliation is a very effective tool for directing how energy flows and it's destination in the plant. That just stresses out the tree in
my opinion as the leaves provides food for the tree. Stress occurs when a plant is operating at or near the limits of what it is genetically programmed to tolerate. Since these trees (above) are in the 20 year old range, you would think that the amount of stress I've put them through would have ended their stopover on this earthly plane, but not so, as you can see. STRAIN, on the other hand, is something to worry about. It occurs when the plant is using more energy than it can create via photosynthesis. IOW, when it cannot surpass it's light compensation point (LCP), which is the point at which the plant is producing at least as much energy (food) via photosynthesis as it uses during respiration. A plant's failure to meet its LCP is always fatal unless the trend is reversed, but even brief periods (a month or 2) of strain are tolerable to otherwise healthy plants, see above. If you slowly
transition the tree whenever changing the environment to inside or
outside, the leaves will not burn or drop.This is not true, and at a minimum needs qualifying. Leaves are unable to adjust to significant changes in light levels, especially when the photo load is decreasing. If we rate light levels from 1-10 with 10 being brightest, a leaf adapted to a light level of 3, 4, or 5, won't be able to adapt to levels of say 9 or 10, no matter how careful we are or how longwe stretch out the reacclimation process. A leaf that comes into existence and is conditioned to light levels of 9 or 10, might only be able to tolerate a reduction in photo load to a level of 5, 6, or 7 before the plant's chemical messengers signal plant central the leaf should be shed and another grown to replace it. In some cases, it can be better to take a plant from low light indoors and move it directly outdoors into full sun, instead of fussing around with an "acclimation" process. I also do that regularly. The leaves burn (or I remove them because I know they will burn), and are quickly replaced by a new and pristine flush of foliage perfectly adapted to whatever light level exists where the tree is sited.As for growing inside, citrus are not really indoor plants. Can you name a plant that IS an indoor plant, or would you say that ALL plants are outdoor plants, just that some outdoor plants tolerate indoor conditions better than others? In newer
modern homes, the dual pane windows are designed to keep harmful rays
out. This may or may not be true, and it would be false in a significantly higher fraction of applications. With every new home I have purchased, the builder boasts about
windows blocking the UV rays so there is no fabric fading. Those
destructive UV rays are what plants need. No, all types of UV rays are potentially harmful to plants, and the shorter the light's wave length (the closer it gets to x-rays), the more harmful the radiation is. UV-A can be helpful in several ways, but UV-B and C are seriously destructive. Plants do NOT need UV light to carry on photosynthesis. UV light can damage and alter plants' DNA, alter photomorphogenic responses (the ability of
plants to sense light),trigger release of free O- radicals (the same free oxygen radicals found in H2O2 [hydrogen peroxide]) that destroy cell membranes and organic molecules (lipid peroxidation), and bleach hair/clothing.

I'll stop here, but the rest of the offering is equally as misleading, so my suggestion is that it be taken with a grain of salt.

Al

Consider it a challenge :)

Citrus can also be grown in low light and cool temps over winter. Not sure how feasible that is for a young plant, though.

Can we lose the combative tones? We're all friends here, we may have different ways of doing things but have the same goals and many people have success with differing methods. I prefer science-based methods but I'm not offended if someone wants to do crazy things (I also like crazy things). Take in all the info, try a few things and see what works best for you.

If most of the information I have stated is incorrect for the typical citrus owner, then the majority of the information found on the internet is incorrect as that is where I find it.

Al, my problem is that whenever you post, it's paragraph after paragraph about scientific stuff that I don't really care about. Just make it simple for the average person in the least amount of words. When helping other people with their trees, do you think the average person wants to read this?:

"UV light can damage and alter plants' DNA, alter photomorphogenic responses (the ability of
plants to sense light),trigger release of free O- radicals (the same free oxygen radicals found in H2O2 [hydrogen peroxide]) that destroy cell membranes and organic molecules (lipid peroxidation), and bleach hair/clothing" Or " This is not true, and at a minimum needs qualifying. Leaves are unable to adjust to significant changes in light levels, especially when the photo load is decreasing. If we rate light levels from 1-10 with 10 being brightest, a leaf adapted to a light level of 3, 4, or 5, won't be able to adapt to levels of say 9 or 10, no matter how careful we are or how long we stretch out the reacclimation process. A leaf that comes into existence and is conditioned to light levels of 9 or 10, might only be able to tolerate a reduction in photo load to a level of 5, 6, or 7 before the plant's chemical messengers signal plant central the leaf should be shed and another grown to replace it. In some cases, it can be better to take a plant from low light indoors and move it directly outdoors into full sun, instead of fussing around with an "acclimation" process. I also do that regularly. The leaves burn (or I remove them because I know they will burn), and are quickly replaced by a new and pristine flush of foliage perfectly adapted to whatever light level exists where the tree is sited." TOO MUCH INFORMATION.

I could do rebuttals to all of the above posts, but it's not worth the stress. People can take what they want from the information given and do whatever they want.

@ lucky_cloud.... Combative tones? You must be from California.... LOL =P In NYC, the tone is that of an exuberant discussion, nothing more ;) If I took offense I would bother responding to the secondary jabs, but, alas, I didn't and it will add nothing to the OP's bundle of info. to help the little seedling grow into a tree that is a show piece in any room by responding any further =)

@tapla.... Nice work on those Bonsais! Particularly like the flowing curves and form of the second specimen.

@ dialt.... As for the cold air transfer from your windows concern.... You can place a piece of styrofoam on the 3 sides of the pot which do not face a heat source & leave the side facing the room exposed for warming (can be attached in a temporary manner using double-sided tape). The little tree will be fine as warming/cooling cycles are natural for them.... You just don't want to over-chill the roots in a plant that young. An older tree would be OK.... What it will do, however, is slow down or stop its growth during the cold months of winter. Again, that's not necessarily a bad thing for a tree in a pot. as you're aiming for a healthy specimen and manageable size --- or as shown above a healthy Bonsai. One thing to keep in mind with your cool window spot is to factor it in when thinking about transplating/repoting/significant pruning/fertilizing.... Always do that in mid-late Spring when temps. outside no longer consistently go below 50˙F. That way, the tree will respond within the normal seasonal process and start putting new growth out, etc., in its usual seasonal cycle.

One other thing root trimming & pruning from height together accomplish -- which I forgot to mention and is important for trees in tight quarters --- is that they make for sturdier trees... What you get -- somewhat like the Bonsais shown above --- is a miniature tree as opposed to a spindly looking sapling with a trunk too weak to support its upper branches. When a tree cannot grow upward, it puts its growth energy elsewhere forming thicker trunk(s) and branching out more -- some even put out more leaves. You start encouraging branching once the seedling is about 20" tall if it hasn't started to branch on its own in particular. That way, you have a tree that will be free standing without needing supports to keep it upright =)

AL,

Do I have to defoliate my trees whenever I transition from inside to outside? Is it a must? Thank you.

See... It's not that most of the info. on the internet is incorrect..... It's a matter of what that info. is being applied to that's the issue, I think. You don't grow indoor, potted trees the same way you would an outdoor potted tree.... And you certainly don't grow ANY type of potted tree the way you would an in-ground tree. Also, the info. you're dealing with here is more on the experience side rather than just regurgitation of what's available elsewhere.... Two of us have provided info. to the OP that we are currently putting into practice growing trees in relatively the same manner that the OP wishes to grow their tree. There's a VERY big difference.... Not everything you find written on paper or internet proves to work in practice --- for instance, don't grow an orchid in a window where it gets full, unfiltered sunlight because the leaves will burn... Well, my mom not only grows them in fully sunlight windows (with western exposure no less) but those specimens outperform by leaps and bounds specimens treated according to "expert" advice. Plants are living things.... They don't always conform to what experts think they should conform to.... Couple that with plants being grown outside their normal element and you will find it to be the case, time and time again, that someone's experiences growing the same plant in the way that you want to do so proves to be more valuable than just expert knowledge gleaned from the internet. I mean, look at Bonsais -- like the ones above .... They fly in the face of all conventional plant growing info. They should not be able to survive, much less become works of art that live to ages far beyond what a naturally grown specimen would achieve.

Yes, the scientific info. may have been a bit much, but sometimes it is necessary to explain WHY a particular method for growing potted trees which are not winter hardy is employed and why success is greatly diminished when not employed. And to point out that the method is common practice and beneficial to the tree for scientific reasons, not just based on one person's success. 'Cause the fact of the matter is most plants' leaves do not heal from excessive trauma --- the nutritional supply is simply cut off & the leaf/leaves is/are allowed to die, fall off and are replaced -- the problem is that it's a slow process & doesn't fit well with short growing seasons outdoors. It takes far less energy to replace a damaged leaf than it does to limp along with one that cannot optimally add to the photosynthesis process. That's where science and common sense meet ;) It is no less harmful than a tree losing its leaves in autumn and growing new ones in Spring. I will say, that MOST people who employ the method don't remove every single leaf, just ones that grew in the environment the plant is being moved out of. And, really, many plants will do this on their own anyway... When I move my tropical hibiscus indoors to overwinter in a sunny window exposure where it eventually blooms, it begins to shed outdoor-grown leaves within 2wks. of being moved and starts to grow new ones in about 30days.... That's without me doing anything to it but moving it. In the Spring, I help it along by removing all its indoor grown foliage and reshaping the shrub because it simply struggles and limps along for far too long on its own -- without intervention, it gets to be about August in zone 7a before the plant has recovered enough to bloom.... and by mid-Oct. temps. are already getting too cold for it.... Will the experts tell you that? Probably not.... Because all they care about, in most cases, is the hard science.... And there is much more to growing plants -- particularly trees -- in pots than just flat out scientific facts.

And if you've had issues with your own trees with mites and other infestations -- disease or pest -- using conventional, expert techniques to grow your trees and those of us employing methods you decry don't have any of those issues who is actually giving the bad advise.... Right? My citrus hybrid has never been attacked by mites or flies or mildew in the five yrs. I've been working with it to shape it into a dwarf specimen.

@ Kulasa Kalabasa.... It isn't an absolute must, but it will benefit your tree to do so.... However, try to remove foliage that has grown indoors. On most trees, the leaves look significantly diff't. Then, once the tree starts to put out new foliage to compensate, you can remove the rest if it needs to be removed --- if it looks unhealthy or unsightly. And it's advisable to do this when it's near the lower end of its low temp. tolerance, especially for very young trees. So, if the lowest end of thriving tolerance for my Hibiscus is 60˙F, I don't put it out and defoliate it before temps. consistently drop no lower than 63-65˙F. It's also a good idea to protect the tree from cold rain during the transition process. Once it starts to put out new leaves, it's good to go with whatever nature has in store.... It might need just a little more protection to get it there --- particularly if you're dealing with a specimen that is more tropical in nature.

Also note that not ALL plants tolerate this method. So it's always best, until you know your plant's tolerances better, to remove only a part of the foliage rather than the whole. And be sure to couple this with addition of fertilizer for the growing season, not just defoliation. Some species will completely give up on the branches defoliated and start new growth from the roots only and you are not likely looking to have that happen when growing a tree. Leaving the foliage it grew outdoors the previous season in place until the foliage you remove is replaced by the plant will avoid this problem. Even leaving 1-2 leaves from the previous season intact per branch will ensure the tree will grow new leaves along it rather than ditching it.

Hope that helps... I'm sure all will kick in some more of his own expertise =)

Thank you for replying fizgig777. I apologize, I do not understand your advise on when to defoliate. Do I defoliate it BEFORE I put it out and defoliate only when say it's 35F outside for my Kaffir lime? Thank you fizgig777.

DB - First, I don't post for your benefit. I've already determined you're not interested in what I have to say, and that's no problem from this quarter; so please skip any post I write if you like. I have no interest in trying to change your mind, but I do have an interest in seeing others get reliable info and are not misled. Too, it goes w/o saying that you should feel perfectly free to rebut whatever I say. I'm perfectly capable of remaining on topic, resisting anything ad hominem, and explaining exactly how I arrive at my conclusions, though I'll reserve the right as part of any debates that arise, to point out errors of reason and/or logic. In the same way I invite your response to my offerings, I would hope that you would welcome the same. Much can be learned from dissenting opinions, and one of those things is that all opinions are not created equal.

Hi, LC. If I might say, I don't think we all have the same goals at all. I actually think our goals are very widely divergent as related to providing information.

If no one pushed back against myth and misinformation, this site wouldn't provide much in the way of learning opportunities. Correcting misinformation can be, and more often than not is, just as valuable as providing reliable information. Both are in the best interest of fora participants because they both eliminate the frustration and heartache that inevitably comes from getting bit on the butt by applied misinformation. ..... better to KNOW in advance that something offered is misinformation than to act on it and find out the hard way. If it's stated that apples will start rising from the tree tomorrow, is it better to know the thought is folly and treat it as such, or would you suggest that someone should start making preparations to ensure the thought is given equal time, attention, and consideration in the physics classroom? What if we don't treat it as folly, and demand it should stand on equal footing with every other opinion? How then do we decide what course?

I say - state your case, support it to the best of your ability, and let the chips fall where they might.

KK - defoliation and partial defoliation can be used to slow development in some parts of the tree and speed it up in other parts. It's especially valuable when trees/plants are apically dominant. An apically dominant tree might allocate roughly 2/3 of it's total energy supply to the top 1/3 of the tree. By thinning the foliage in the top 1/2 - 1/3 of the tree and pruning harder there than on the lower 1/2 - 2/3 of the tree, you can force the tree to direct energy to areas of the tree that would otherwise be showing a decline in vitality. It's particularly useful in applications where the plant's appearance is the focus.

It's not a must. You can still try gradual acclimation if you feel more comfortable with that, but you'll find that in most cases, the indoor leaves are most likely going to be shed in the 4-8 week period after moving them from in to out ----- unless you had them in an extremely bright sunroom or under high output lights.

*****************************************************************

I don't look at it as my job to make up someone else's mind - above my pay grade. It's better to try opening minds by providing information in a way that instills the feeling it (the info) has to be dealt with. Far more often than not, when the decision-making process is so intense you can escape only by thinking, you'll know what the right decision is. You might not follow through with it, but at least you'll recognize it.

Al

I have always found that the best way to learn is not from experience; that is too often costly and painful. The best way to learn is from the experiences of others; it is painless and free. You may have noticed that some people here are a little too thin skinned and prone to be insulted rather than try to learn. DB is one of those. The first time I tried to deal with her, she was personally insulted and thought I was a pig; while I was only being my usual curmudgeon self. I think everyone here should try to learn from the experiences of others and try NOT to be offended.

johnmerr, please show me the post where I called you a pig. If I were to call you anything, it definitely would not be a pig. lol.

Denise,I never save negative things... Sorry.

More times than I can possibly count, I have seen advice to do something that makes no sense from the scientific perspective, which essentially means it makes no sense at all, period. It's not at all uncommon for someone to scoff at one of my pedantic posts. Often it's someone who thinks experience is the most important rung on the ladder to green thumb status, but I can tell you it isn't. What good is 20 or 50 years of experience if it runs to doing the same thing over and over, often times wrong or ham-handedly? Wouldn't that be 20-50 years of largely wasted time?

In the same vein, observations made that attribute an affect to an impossible cause are also extremely common. Knowledge provides pieces to growing puzzles, and the more pieces of the puzzle we have to work with, the easier it is to see the big picture clearly, which is why learning is so beneficial to increasing our effort:reward quotient.

I think though, that the most important aspect of maintaining a store of knowledge lies in our ability to accurately assess our observations. Growers who have taken the time to gain working knowledge of the science behind what makes plants tic, can make observations within the limits of what science allows, instead of making up science to fit their observations - the stuff of which horticultural myth is born. This gives folks who really want to learn and understand, a very significant advantage over those taking the more laissez faire (literally: leave things alone) approach. Resolving issues by accurate assessment instead of guesswork eliminates most of the painfully slow process of learning by trial and error associated with those that think experience should carry the day.

Learn all you can so practical application, your 'experience', becomes a validation of your storehouse of knowledge, instead of your source of knowledge. Why is this a better arrangement? Because the more you know, the more difficult it is to assume in error, and the easier it is to winnow improbable possibilities to get to the probabilities. You'll leave the 'trial and error crowd' standing in your slipstream wondering what happened.

Al

@ Kulasa Kalabasa.... Sorry for the confusion/unclear response.... You defoliate before you put it out once the outside temperature is consistently above 60˙F. So once the temperature hits that low threshold (for a lime), you can trim off the leaves it grew indoors and put it outside in full sunlight. If it's a very young tree, also shield it from cold rains until the new foliage appears.

Hope that's clearer =)

Some people have 30 years of experience; and others have one year of experience, 30 times

I think Al means well by trying to educate the hoi polloi. Problem is, by the time one gets to the end of one of his lengthy posts one forgets what Al was trying to explain in the first place.

Al, you said: Often it's someone who thinks experience is the most important rung on
the ladder to green thumb status, but I can tell you it isn't.

In the past when I asked for scientific references for some of the things that you have said you avoided providing them and instead told me that I should trust you because of your many years of experience.

Here we go with another kerfuffle with Al in †he middle of it all.

And the fool will always try to belittle someone who is more knowledgeable or better educated ---- even if to their own detriment --- since, as all fools know, a pound of ignorance trumps an ounce of wisdom, common sense, or education .... It is an utter waste of time to try to instill any knowledge in a fool, because, as one comedian so aptly stated/observed, "you can't fix stupid"....

An intelligent person would realize there is much knowledge to be gleaned from Al's posts above -- lengthy or not. Interesting how someone who had nothing useful to add to the OP's request for info. is chiming in with criticism, though....

Fiz, you criticize me and call me a fool. So now we are down to name calling.

Tell me how my criticisms of Al are not accurate.

As for OP's request for info, it probably is some sort of citrus, although I cannot determine what type. Leave it in its pot for now. Keep it in a south facing window. It will survive the winter with proper care.

Proverbs 18:2.... Never engage in a battle of wits with an unarmed person.

Hello, Al.

Thank you for replying. I want to make sure I got this thing right, so I will write what I understand from your posts in this thread. Before anything else though, I would like you to know that I am a fan. I have read plenty of your articles here. They have been my guide in growing my citrus trees in containers. In fact, if you check my phone right now, most of the pages I saved and bookmarked on my safari are always of you discussing something in this forum. I am no expert and I don't claim to be, but I do love learning. I learn by making sure I have a good grasp of the theory so I can apply it as is, and test it to validate it. Then I stick with what is true and what is not applicable to my particular growing conditions. Even though there are so many variables at play in this hobby, the basic principles remain the same. Thank you for teaching me those.

When I read your reply on the defoliation when transitioning, I rattled. I don't remember reading anything about that. You said you do it regularly, so I was under the impression you do it every time you transition. It is not a must then. Do you only do it to your bonsai trees? To make it clear, there is really no need for defoliation when transitioning, am I correct? Leaves grown indoor during overwintering are usually bigger than outdoor leaves. If acclimated correctly, there is really no harm leaving them on the tree. Their function is not diminished by them being grown indoor if they are acclimated correctly, am I right? Of course, pruning during active growth is different from defoliating indoor leaves when transitioning. That's not what this is about. I do prune, but I do not selectively remove indoor leaves when transitioning. Thank you for sharing your knowledge, I really appreciate it.

Fizgig77

I love hibiscus. My tropical hibiscus do not shed leaves when I take it inside the house for the winter. I acclimate it well. That being said, I believe they do not shed leaves on purpose in order for them to grow new indoor leaves (so that they can adapt to their new environment). They shed leaves when they are unable to adapt and adjust to their new environment. Also, when the tree is getting good amount of light but the roots are not warm enough, it will also drop leaves. We are talking about defoliating citrus, right? I just want us to be on the same page, I don't want to be talking with citrus in my mind while you respond with hibiscus in your mind. I have never defoliated my tree of indoor growth so this is all new to me. I do canopy prune during active growth but I do not root prune as I don't see the need to to do it because I up pot. Maybe when I get tired of moving big trees in and out, I will root prune to confine them in their pots. I do not have any issues about them being root bound because again, I up pot. Anyway, it's late I have to get some sleep. Goodnight!

Oh, wow. All civility down the drain?

V - your memory fails you or you're making things up. I've never asked anyone at GW at any time to trust me, and certainly not because "I have experience". Lol - I'm not that needy - I figure either you trust me or you don't. Also, If I say something you think is in error, it's not up to me to prove to you I'm right. If you think I'm wrong, ignore me or show me how/why I'm wrong. That's how I've always conducted myself because it saves grief.

As I mentioned before, It's not so much that I avoid answering your questions, I actually try to avoid you, but you always seem to find me (witness the 3 rapid-fire posts above and the snotty post you left on the container forum last week) and complain/castigate me for not taking responsibility for your lack of understanding of some of the basic points of growing in containers. I don't think there are many more patient than I at GW/Houzz, and my willingness to help others is pretty evident, but I've seen you ask questions over and over that I and others have already answered several times, questions you should have the answers to by now, given the amount of time you've spent discussing soils. I told you the same thing last week. I simply reached the point where I really don't think I can help you. You said you're a scientist, and there are plenty of other people with a good working knowledge of soil science you could petition for answers, or you could try your own hand at ferreting out the info instead of wasting time worrying about me.

Al

I have moved my hibiscus every year (for the past 30 years) from direct sun to a west facing window and back every year no leaf loss. I only transitioned it from indoors to direct sun.

"I think Al means well by trying to educate the hoi polloi. Problem is, by the time one gets to the end of one of his lengthy posts one forgets what Al was trying to explain in the first place."

No, most people have an attention span longer than the 5 minutes maximum it takes to read one of Al's posts. Especially if you are reading it to obtain knowledge, not with the intention of getting through it so you can blurt out a thinly-veiled insult.

When Al contributes, he takes the time to provide the science behind the advice, instead of immediately offering up a contrary opinion based on nothing more than personal experience in a vacuum, or boasting how many years of experience he has.

Nothing is worse from a learning perspective than to ignore the scientific reason things work the way they do. The people who do are doomed to a life of random experience, trying to complete a puzzle with no box in a dark room.

Worse are the people who think they are done learning, and shut themselves off to any further information. These people, still feeling a need to contribute, simply state outdated and often harmful advice without an explanation of why it works. Then they become indignant when someone disagrees with their gospel, and enraged when they back it up with scientific proof.

It would never occur to me to pull leaves off my tree to transfer it from inside to outside. I do move it to shade and wind shelter on hot bright days and only expose it to morning and evening sun. I'll move my trees to cloudy mid day sun. Burning is the biggest problems. Wind and temperature come next according to each ones intensity. I have placed trees in plastic bags to reduce moisture loose when shade is not enough. To pluck or not to pluck is the question of importance.

Steve

The new leaves on that seedling appear to have narrow winged-petioles so I think you may be able to rule it out as being a lemon. There is a paper here that had a nice picture of some leaf examples and IDs -

Morphological variability of leaves of 37 accessions of Citrus L. and related genera.
a 'Nasnaran' mandarin (C. amblycarpa), b 'Galego Inerme Key' lime (C. aurantiifolia), c 'Narrow Leaf' sour orange (C. aurantium), d 'Bergamot' orange (C. bergamia), e 'Taiwan' mandarin (C. depressa), f 'Mauritius papeda' (C. hystrix), g C. hystrix hybrid, h 'Variegated' true lemon (C. limon), i 'Talamisan' orange (C. longispina), j 'Etrog' citron (C. medica), k 'Variegated' calamondin (C. madurensis), l 'Chinotto' orange (C. myrtifolia), m 'Star Ruby' grapefruit (C. paradisi), n 'Cleopatra' mandarin (C. reshni), o 'Fairchild' tangerine-tangelo [C. clementina 9 (C. paradisi 9 C. tangerina)], p 'Szincom' mandarin (C. reticulata), q 'Valencia Trepadeira' sweet orange (C. sinensis)\, r 'Variegated' sweet
orange (C. sinensis), s 'Jaboti'

You may want it to grow a bit more to see what those leaves (and their petioles) do as they mature but it may be some kind of orange or pommelo descendant. I know it sounds crazy but I think it is cool that some of these citrus do that "winged" petiole thing (and to different degrees). You could always rub and smell the leaves to help determine what it is too. Good description of that here - http://idtools.org/id/citrus/citrusid/morphology.php?state[]=leaves

...where the last paragraph at the link notes this -

The scent of crushed young leaves is one of the most helpful characters to distinguish broad cultivar groups within citrus. If possible, calibration at a citrus arboretum or collection would be useful prior to field survey. With some exceptions, scents are distinctive to cultivar group (e.g., sweet in sweet oranges, grapefruits, and pummelos; freshly spicy in lemons; spicy/peppery in sour oranges). Scents can also be useful in distinguishing particular crosses with trifoliate orange; for example, mandarin crosses smell like mandarins, and lemon crosses smell like lemons. Calamondins are unusual in exhibiting a scent reminiscent of bread dough.

Avoid pulling leaves off when defoliating because it can damage the axillary bud or tear off enough bark that it dries up. Use a sharp pair of scissors to cut through the leaf stem between the leaf and its attachment point.

Keep in mind, guys, that I said that I brought defoliation as a rebuttal to the sweeping statement of someone who expressed they never heard of such a thing. It's an excellent tool, but the tree does take a hit. I'm constantly (as in daily) pruning leaves off my bonsai and cutting other leaves in half. Obviously, it slows development of the plant; but, if you're moving a tree outdoors and want it in full sun, more often than not, the leaves will be shed anyway. Sometimes the shedding is a leaf here & there until all the leaves are replaced - one might not even know it.

Partial defoliation to complete is also particularly valuable after or during a hard root-prune or when transplanting out of season. I might add that when someone doesn't have a feel for repotting and how trees respond to it, they usually parrot the contemporary advice that the leaves are necessary because they are the plant's only source of food. That's fine advice for a narrow set of circumstances where you're taking a trees out of a nursery cans or are planting B&B stock and just dropping the tree in a planting hole. Trees with root systems that are significantly compromised by root pruning or transplanting often simply collapse or shed branches important to the composition. If the tree is healthy, odds are very high that it has enough energy reserves to push a new flush of foliage, opening latent buds only as the root system is able to support them.

Defoliation techniques reduce internode length, reduce leaf size, redirects energy flow, and can save branches that otherwise would be shed. If you want a tightly grown compact tree with LOTS of branches/foliage, learn how to pinch and use defoliation.

Finally - If you want your tree to retain any fruit it's supporting, don't defoliate unless it's necessary to the tree's survival. It's primarily a technique used to redirect energy flow and improve appearance, but it IS a valuable tool that can help ensure survival of the plant in certain circumstances.

Al

" if you're moving a tree outdoors and want it in full sun, more often than not, the leaves will be shed anyway".... true; but the big difference is first the tree will suck back nutrients from the leaf. IMHO... let the leaves fall where they may.

That was your interpretation of Proverbs 18.2 which is 'Fools take no pleasure in understanding, but delight in airing their own opinions'.

@ Kulasa Kalabasa, et al.... Regarding defoliation of tropical hibiscus.... There is one difference in my plants' situation that may be the key to why mine has to be defoliated when being move outdoors after overwintering indoors while others have experienced no such need..... When my plant is taken in for the winter --- once temps. consistently drop below 55˙F at night, my plant is no longer happy outdoors and exhibits signs of cold stress -- it is usually somewhere in the mid-Oct. to end of Nov. range --- depending on what the climate is doing that year..... So, at that point in the year, it is receiving no more than 5hrs. of direct, unfiltered eastern exposure sunlight..... And it goes inside to receive no more than 3hrs. of heavily filtered (through UV coated windows & drapery) indirect sunlight.... It remains in those conditions until mid-May or mid-June when temps. consistently stay above 60˙F..... With that change from outside to in, the conditions are so drastically diff't that the leaves it grew in abundance outdoors are slowly shed --- I don't defoliate the plant when I take it in as such, just remove some of its leaves to allow for better light penetration throughout the large shrub indoors -- and it grows new leaves indoors and eventually does bloom, too..... So it has the bare minimum it needs to survive the roughly 6mos. it spends inside, but it definitely isn't thriving..... When it's time for it to go back outdoors, it usually encounters no less than 8hrs. of direct, unfiltered eastern exposure early summer sunlight.... The large, delicate foliage that grew indoors cannot tolerate those conditions. Rather than wait for the plant to go through the process of shedding leaves and trying its darnedest to acclimate --- the first couple of years of owning it, that's what I did and it took the plant no less than 2mos. to finally acclimate by which pt. the growing season for it in this zone is just about half over --- I defoliate it to speed up the process of acclimation to the outdoor conditions -- especially since that's also when I prune the shrub. The indoor leaves would have issues not just with the sunlight change, but, more often than not, insane and sudden change in the high temps. they must endure outdoors..... By June this area can have sudden heatwaves where temps. get into the mid-90s.... Those thin indoor grown leaves would simply fry just from the heat alone. At the height of summer heat, I've measure temps. in the full sunlit environment on my terrace where the Hibiscus spends the summer months in excess of 105˙F.... And if we have a heatwave -- when we average about 5 a year --- then temp. can reach 110˙F easily. The Hibiscus luvs the heat, but if I didn't speed up the acclimation process by removing all indoor-grown leaves, the high summer temps. would likely kill the plant off.

Those folks who have said they don't have any issues when moving their Hibiscus outside either have similar enough conditions between environments and/or are dealing with diff't types of hibiscus and/or have strains that are less sensitive. Because, believe me when I say I don't go through the defoliation process out of sheer joy.... It's very time consuming & my shrub isn't a small one either! But it speeds up the acclimation process by at least a month most years --- sometimes ever further if Spring suddenly turns to summer out of the blue.

So it's not just a choice to do this or not..... Sometimes it's what your individual plant needs to thrive. What is necessary for one plant may not be necessary for yours.... Environmental conditions play a large part. And you'll find significant difference between cultivars, too. Mine is highly hybridized with large double flowers. It's pretty forgiving -- as most are --- of sudden changes in conditions, but not without human intervention. My neighbor had one that was exactly like mine.... She took it from indoor near darkness to outdoor full sun exposure without doing anything for it but moving it.... The plant struggled along for about 2mos. then died when the summer heat kicked in.

KK - your post somehow got obscured by the hail of incoming - sorry I missed it. ..... and thanks for the very kind words - much appreciated. This thread was posted to 3 different fora, so I'm not sure which one you meant when you said "here". I'm curious and would appreciate knowing that.

KK mentions: When I read your reply on the defoliation when transitioning, I rattled. I don't remember reading anything about that. You said you do it regularly, so I was under the impression you do it every time you transition. When I think about it, I only transition broad-leaf evergreens from in to out. A large fraction of those get completely defoliated the day I move them outdoors, and pruned so all the leggy winter growth is removed. Getting into that habit ensures that when it's necessary to force back-budding, the buds won't be occurring on lanky past winters' growth. I work to make sure my trees have only retain summers' growth. Here, it's important to realize that for me, appearance is secondary only to the tree's health. It is not a must then. Correct. you can defoliate if the tree is healthy and your comfortable doing that, you can simply move the tree to a bright spot and let what leaves will burn, burn, or you can go through an acclimation process. Do you only do it to your bonsai trees? No I have lots of trees in pots as garden accents that I use defoliation techniques on. To make it clear, there is really no need for defoliation when transitioning, am I correct? Yes. It's primarily used as a way to make trees fuller and more compact, and to increase ramification (leaf and branch density) ..... but it IS a viable way of getting rid of ALL old tattered/spoiled foliage, which is soon replaced with a flush of new and pristine leaves perfectly adapted to it's site. You need to be able to keep your trees reasonably healthy to ensure the tree doesn't collapse when its defoliated. I've never lost even one tree as a result of either full or partial defoliation, and as mentioned, I use the tool on a daily basis (during summer). Leaves grown indoor during overwintering are usually bigger than outdoor leaves. If acclimated correctly, there is really no harm leaving them on the tree. Their function is not diminished by them being grown indoor if they are acclimated correctly, am I right? Not quite correct. Leaves that come to being under low light conditions have different leaf structures that impact its photosynthesizing ability. One significance is the number of stomatal openings on 'sun grown' leaves. There can be a difference greater than 75% between sun leaves and shade leaves. I'm fairly certain that 83% was the figure used in the last study I read about light acclimatization, but I'm relying on memory here. Shade vs sun leaves have several differences in the photosynthesizing machinery, too. Pallisade and spongy mesophyll layers are thicker and more densely packed in sun grown leaves. Strangely, trees grown in shade have a lower LCP (light compensation point) than trees in sun. It takes less light to reach the break-even point (photosynthesis:respiration) for trees grown in shade. The disadvantage is, shade grown trees often tend toward a prostrate growth habit because their trunks don't thicken like trees in sun. Of course, pruning during active growth is different from defoliating indoor leaves when transitioning. That's not what this is about. I do prune, but I do not selectively remove indoor leaves when transitioning. Thank you for sharing your knowledge, I really appreciate it. My pleasure. Fare well.

Al

Wow this has been some thread to read, particularly in a forum that normally sees a much slower discussion pace. I would like to add a few points of thought from an outside observer, I grow all my citrus in ground on the 8b/9a line in Louisiana, so have nothing to add to container citrus discussion, as all I know about it is from what I have read online.

What I would like to point out is that not all growing conditions are the same, even when talking about indoors in the winter for citrus. I live on the northern edge of where it is practical to grow most types of citrus in ground, even then I am limited to the more cold hardy varieties. For some people growing container citrus like those not far north of where I live, may mean bringing the citrus indoors for a few weeks per year, others may deal with needing to keep them indoors for half the year. Then the indoor environment itself will vary, some people in more moderate climates using large containers may simply move their trees into a unheated or minimally heated garage, others may be in colder climates and have to deal with some of the above mentioned window sill conditions, dry heat, under window radiators, etc, on the other extreme there will be people that have to worry about excess humility, too much heat from sunlight in a window sill, pests, etc. To put it another way the conditions indoors (using the term loosely) for container citrus may be very different in Atlanta GA, vs Chicago, vs where ever in hours of daylight, temperature, humidity...

Ike

Nothing in what Ike said to disagree with, but I almost always tend to look at things from the plant's perspective. Genetics determine what conditions best (note the use of superlatives) suit a species, so plant material from the same source (genetically speaking) will respond most favorably to a very narrow range of cultural conditions. This will be true no matter where the plant is grown. Plants from the same genetic source will want exactly the same conditions in TX or FL as they want in more northerly climes. The limiting factor really isn't where the plant is grown, it's how close the grower can come to providing conditions that allow the tree to realize as much of its genetic potential as possible.

An example might be seen in the frequently held debate re whether terra cotta or plastic/ceramic is better for the plant. Arguments for plastic/ceramic tend to center on the contrast in appearance, color choices, or the fact that plants in terra cotta need watering more often than the grower thinks (s)he can manage. While all true, these points have nothing to do with what the plant actually wants. The plant prefers the gas exchange and evaporative cooling afforded by terra cotta, so it would prefer the grower to give it what it wants and water 2-3 times each day. The grower decides (s)he can't or won't water 2-3 times each day (same thing I'd say) and opts for plastic, it's a compromise. There is nothing pejorative in that statement. As we order our priorities, we make dozens of compromises every day, but trying to explain the concept of compromise to someone who just made one isn't always met with a smile.

In the end, the grower's job is to figure out what is limiting the plant's ability to realize the potential that was Mother Nature's endowment, and fix the limiting factor to the degree (s)he thinks is reasonable. Geography definitely changes the facility with which we can address the limitations, but it doesn't change what the plant wants.

Al

Al, one point here, theory is all good, but experimentation also comes into play, to borrow from a debate when dealing with a different type of plants. There is a debate about the benefits of using pine straw mulch when growing blueberries in the southeastern US. The theorist all say that it should not effect soil pH as lore implies (blueberries prefer very low pH soils in the 4.5-5.5 range), yet study after study shows that in real world test that blueberries in the region grown in beds with pine straw mulch outperform those that are not.

Perhaps it has nothing to do with lowering the pH. It could as easily be a more obscure factor.

What I said doesn't at all imply folks should stop experimenting or searching out methods and materials that benefit the plant or eliminate or lessen the impact of limiting factors. In fact, just the opposite is true. I don't disagree with what you said, and can't see how what I said can't live peacefully side by side with your points. It's not a case of the perspectives being mutually exclusive.

Your example illustrates that at some point in time, someone discovered how to provide the plant something closer to exactly what it wants/needs. Nothing more can be asked of the grower than that.

I have noticed that when someone is at the top of their field that they can get a lot of flack and pressure Some is deserved but the overwhelming majority is uncalled for. I have personally never been more than an average person so I have never experienced this phenomenon.

My growing situation is so out of the ordinary for growing citrus north of zone 7 that I must sometimes use unorthodox methods. I have a very high level of respect for those who rely on their knowledge and experiences for their successful career.

"yet study after study shows that in real world test that blueberries in the region grown in beds with pine straw mulch outperform those that are not."

Would love to see documentation of those studies :) It may be that the pine straw mulch is just providing what any good mulch would do..... insulating the soil and preventing moisture evaporation. It is sure not helping maintain acidity as that has been quite soundly disproven to be a factor.

FWIW, the PNW is one of the largest commercial blueberry growing areas in the US, both for fruit production and as the wholesale growing source for vast numbers of blueberry plants for countrywide distribution. And while we do have acidic soil conditions, they are not overly acidic.....anything much lower than 5.5 would be extremely unusual and 6.0-6.3 is much more typical. Pine straw mulch is just not available in this region and in fact most commercial fields are not mulched at all. Meadow grass is allowed to grow between bushes and is mowed back as needed. The plants are not amended much either, if at all and not fertilized except for containerized plants.

I have been following this thread off and on. Frankly controversies often lead to interesting bits of information and insight and I definitely like how Al handles them. And at the same time he takes the time to explain his reasoning behind them.

Over the years I have started partially/fully defoliating some plants while transitioning from indoors to outdoors. Over the years I noticed Al encourage that for ficus and I tried that on several of my ficus and the results are quite spectacular. The reasoning behind it makes a lot of sense to me.

here is a pure conjecture for what it is worth: Besides Al's reasoning I also suspect that dramatic change in UV exposure has something to do with it too. My hypothesis is that indoor leaves loose the 'natural sunscreen' that leaves have outdoors and cannot regain it back easily. UV is very high energy photons (UVA is 16x more energetic than red) and quite destructive. When a plant is slowly acclimatized, I suspect photosynthesis levels are increased but so does the energy wasted to deal with the destructive powers of UV.

I have tried it (partially defoliating) on several other plants like guava, hibiscus, bougainvillea and few others with great results. Early this season I did the same on a small lemon plant. I am quite pleased with the results. It has all new leaves, two quite good sized lemons and it looks stronger and healthier than it used to be. Compared to that another plant (same lemon and same beginning size) went through a stasis, grew some and dropped some, produced flowers but never set fruit. It is not conclusive experiment but interesting nevertheless.

Vlad you said about Al: In the past when I asked for scientific references for some of the things that you have said you avoided providing them and instead told me that I should trust you because of your many years of experience.

I think you have beaten that dead horse many times, inserting that pet peeve of yours in many threads. It is time to move on. But you managed to embed an accusation that I have never seen Al do. You are referring to this comment: https://www.houzz.com/discussions/miracle-gro-garden-soil-experiment-dsvw-vd~5348646 The reply by Al, in my opinion, was spot on and had no reference to years of experience that you seem to accuse him of. A scientist does what Sherlock Holmes explained best: "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth"

Next you said: Tell me how my criticisms of Al are not accurate.

Just because you cannot get through 300 words without losing the plot is really not a criticism of Al. I wonder how you will get through 10000 words in the scientific reference you are seeking. Out of your five posts in this thread four of them are dedicated to trying to get even with Al. Please try to move on.

Tropic, I have already decided to "move on". It just is not worth my time and energy.

Gardengal48, I don't want to get too far off the subject of citrus here, but the University of Florida, as well University of Georgia have published studies on pine straw and pine bark used in blueberry production, here is a link to one https://fshs.org/proceedings-o/2009-vol-122/FSHS%20vol.%20122/14-16.pdf

It should be noted that there are 4 generally accepted varieties of blueberries, northern lowbush, northern highbush, southern highbush, and rabbiteye (as well as some crosses), though in truth the linage of southern highbush is somewhat questionable and most southern highbushes are really crosses with northern highbush.

I read on the Texas A&M Agricultural Extension website that when root pruning, some of the canopy should be removed. I however do not know if this is true or not.

"If you want to keep the plant in the same container and are happy with the size of your tree, lift it out of the pot, cut about a quarter of the roots or about 2 - 3 inches off, shake off the loose soil, and pot it with new potting soil as above. Prune at lease a third of the foliage off at the time of this root reduction."

https://aggie-horticulture.tamu.edu/patiocitrus/containers.html

I would love to heard other's experiences on this because I would be having to root prune soon.

I didn't read anything on defoliating the leaves though.

Can't remember the name but it's not citrus.imho

Pruning off a third of the foliage IS defoliation.... Not complete, obviously, but that's basically what defoliation is --- removing some or all foliage.

The size of the roots are directly tied to the height of the tree for the majority of trees... Most people prune from the height/canopy of the potted tree when they prune the root system. It's not absolutely necessary, but it is advisable since the point of root pruning is to control the size of the potted tree. If you prune the canopy at the same time it makes for a much sturdier, compact tree. Pruning the canopy will also increase branching. The end result is a more robust small tree rather than a weak, weedy, lanky sapling.

The TX A&M folks do know what they're talking about in the advice given...

Texas A&M Citrus center are among my gurus from whom I learned sooo much. Nice folks too.

John, I personally follow the University of Florida information more, as my growing conditions, soil type, etc, are more similar to the Florida panhandle conditions, than the south Texas conditions.