It wouldn't help any more than fertilizer or table salt would (which they do not). The reason is that ANY solute (fertilizer salts, dissolved minerals in tap water, sugar, baking soda .....) makes it more difficult for water to pass into plant sells. If you wanted to rehydrate a leaf cutting quickly, a fresh cut on the petiole with a sharp, sterile tool and a soak in distilled water is the fastest way - even faster than water containing a wetting agent.

Al

Why distilled water?

I had read that sugar would inhibit roots from uptaking water, but wasn't sure if that applied to a stem cutting.

Ah, answered my own question - you said it above and I missed it. Guess that'll teach me to not sleep and then read forum responses and think I'll comprehend them!

OK, so once the leaf is rehydrated,can or should you use a very weak fertilizer or a bit of SuperThrive to help it root? I'm basing the SuperThrive comment on the auxins that may help root formation.

I guess the question is: what does a leaf cutting need to produce? Is water all it needs? Or does it need food at some point? It might have to live for a year in order to fulfill its job.

I read (but have no idea if it's true or not) that when trying to preserve a cut flower as long as possible there are a few 'tricks' to keeping it fresh looking as long as possible. One of those tricks is to add sugar to the water. The purpose behind the sugar is to provide food to the cutting. Not nutrients, but actual food.

Whether this actually works or is desirable I couldn't say.

Quite honestly, I would use a rooting hormone instead of the SuperThrive... I do use SuperThrive, but only as a fertilizer additive, and not for cuttings without roots.

Providing a little humidity around the leaf cutting may help it while it tries to produce roots. What type of plant is it? What type of medium are you rooting it in? What's the growing environment like?

My bad for not saying Saintpaulia above.

I guess I should have qualified yet more, Jodi. Your responses are absolutely appropriate in the big picture, but I was focusing on a much smaller element: what the leaf needs in terms of uptake of food and water. Is water enough? As JaG said, we often do feed sugar to keep a cut flower longer. Does the same apply at some part of the process? Sure, medium, environment all apply, but given that those are optimal (and some people could debate that all day), what does a leaf (in general, I'd guess, but maybe it's specific to Saintpaulia), need to stay as healthy as it can to provide offspring?

Not that you asked, lol, but for what it's worth, rooting hormone tends to retard propagation in AVs, so I don't use it. But since I didn't say AVs to begin with, you may already know that.

The fact that you're talking about African Violets completely cuts me out of the advice picture! That's the ONE plant I cannot grow to save my life! I swear... every single purchased plant, and every single leaf cutting I've tried to root, have died horrible deaths at my hands!

Now, if we're talking about any other plant type, I do alright by them! Don't ask me why... I really couldn't say!

My plants of preference are Hippeastrum bulbs and other amaryllids, and orchids... so there's no place at the windowsill for Saintpaulia plants... that I would just kill, anyway!

But from what I understand, a leaf without roots can't really uptake necessary nutrition, and the new developing plant feeds off the leaf piece, itself, until it's able to uptake moisture and nutrition through its own newly developed roots. Keeping it moist gives it the right environment for the new roots and plant to develop, and keeps the leaf piece hydrated enough to live until the baby plant or new roots grow.

Perhaps someone who knows a little more can explain the leaf cutting thing better than I...

That's a good start, Jodi. You "hear" all kinds of things from people, but I always want to know the science; nothing makes my heart go pitter patter faster than an experiment, lol.

I also thought that the leaf provided all nutrition to the growing plantlets. But, I am not sure what it can and cannot uptake. If it's only water, then the question is answered.

I've had a lot more luck with these fragile leaves by taking them out of the rooting soil mix once a day and soaking the whole leaf/petiole in water. They seem to now have enough to sustain themselves until the roots grow in, which can be up to a month, or more for a large leaf.

Per growing them, they are really quite hardy....IF you get the watering right. They have little tolerance for too much or too little. They are the Goldilocks of plants, lol. Crowns rot instantly if they are too wet and go limp if too dry. Per rooting, same applies. The soil shouldn't be more than cool to the touch in my experience and never should it feel wet. Not that you have room with all those other lovely flowers, but if you ever feel the urge, I know you can be successful!

I wrote this article, which was subsequently published in Stemma, an online magazine:

Superthrive or Superjivesize>color>

The question regarding the value of Superthrive as a miracle tonic for plants is often bandied about in horticultural circles. Over the years, I had read claims that ranged from, "I put it on my plant, which had never bloomed, and it was in full bloom the next day." to, "It was dead - I put Superthrive on it and the next day it was alive and beautiful, growing better than it ever had before." I decided to find out for myself.

If you look for information on the net, you will probably only find the manufacturers claims and anecdotal observations, both so in want of anything that resembles a control. Though my experiments were far from purely scientific, I tried to keep some loose controls in place so that I could make a fair judgment of its value, based my own observations. Here is what I did, what I found, and the conclusions I made about any value the product Superthrive might hold for me.

On four separate occasions, I took multiple cuttings of plants in four different genera. In each case the group of cuttings were taken from the same individual plant to reduce genetic variance. The plant materials I used were: Ficus benjamina, (a tropical weeping fig) Luna apiculata (Peruvian myrtle), Chaenorrhinum minus (a dwarf snapdragon), and an unknown variety of Coleus. In each instance, I prepared cuttings from the same plant and inserted them in a very fast, sterile soil. The containers containing half of the cuttings were immersed/soaked in a Superthrive solution of approximately 1/2 tsp per gallon of water to the upper soil line. The other half of the cuttings were watered in with water only. In subsequent waterings, I would water the "Superthrive batch" of cuttings with a solution of 10 drops per gallon and the others with only water. The same fertilizer regimen was followed on both groups of cuttings. In all four instances, the cuttings that I used Superthrive on rooted and showed new growth first. For this reason, it follows that they would naturally exhibit better development, though I could see no difference in overall vitality, once rooted. I can also say that a slightly higher percentage of cuttings rooted that were treated with the Superthrive treatment at the outset. I suspect that is directly related to the effects of the auxin in Superthrive hastening initiation of root primordia before potential vascular connections were destroyed by rot causing organisms.

In particular, something I looked for because of my affinity for a compact form in plants was branch (stem) extension. (The writer is a bonsai practitioner.) Though the cuttings treated with Superthrive rooted sooner, they exhibited the same amount of branch extension. In other words, internode length was approximately equal and no difference in leaf size was noted.

As a second part to each of my "experiments", I divided the group of cuttings that had not been treated with Superthrive into two groups. One of the groups remained on the water/fertilizer only program, while the other group was treated to an additional 10 drops of Superthrive in each gallon of fertilizer solution. Again, the fertilizer regimen was the same for both groups. By summerÂs end, I could detect no difference in bio-mass or vitality between the two groups of plants.

Since I replicated the above experiment in four different trials, using four different plant materials, I am quite comfortable in drawing some conclusions as they apply to me and my growing habits or abilities. First, and based on my observations, I have concluded that Superthrive does hold value for me as a rooting aid, or stimulant if you prefer. I regularly soak the soil, usually overnight, of my newly root-pruned and often bare-rooted repots in a solution of 1/2 tsp Superthrive per gallon of water. Second, and also based on my observations, I no longer bother with its use at any time other than at repotting. No evidence was accumulated through the 4 trials to convince me that Superthrive was of any value as a "tonic" for plants with roots that were beyond the initiation or recovery stage.

Interestingly, the first ingredient listed as being beneficial to plants on the Superthrive label is vitamin B-1 (or thiamine). Growing plants are able to synthesize their own vitamin B-1 as do many of the fungi and bacteria having relationships with plant roots, so it's extremely doubtful that vitamin B-1 could be deficient in soils or that a growing plant could exhibit a vitamin B-1 deficiency.

Some will note that I used more of the product than suggested on the container. I wanted to see if any unwanted effects surfaced as well as trying to be sure there was ample opportunity for clear delineation between the groups. I suspect that if a more dilute solution was used, the difference between groups would have been even less clear.

It might be worth noting that since the product contains the growth regulator (hormone) auxin, its overuse can cause defoliation, at least in dicots. The broad-leaf weed killer Weed-B-Gone and the infamous "Agent Orange", a defoliant that saw widespread use in Viet Nam, are little more than synthetic auxin.

Al

FWIW - From the text Plant Production in Containers II, by Dr. C. E. Whitcomb:

"...... Pridham immersed various cuttings in aqueous solutions of sucrose, dextrose, maltose (all 3 plant sugars), potassium nitrate, ammonium nitrate, and NAA for a period of 24 hours in an effort to supply cuttings with nutrients lost when the cutting was removed from the parent plant. He concluded that rooting of cuttings and subsequent growth of the young plant depended primarily upon maturity and treatment of the stock plant, and that response to treatments of growth substances, sugars, and nitrogen are of minor importance."

Sugars are carbon, hydrogen, and oxygen, and all elements are readily available in the water or air, so I'm not sure of what value it might be. Hmmm.

Basically, I think he's saying there is no substitute for a robust parent plant when it comes to ensuring success cutting success.

Al

Thank you, Al... most interesting! I will, henceforth, save the Superthrive for rooting cuttings, and stick with my liquid fertilizer and micro-nutrients for feeding my plants.

Some of us bulb growers are wont to do a Superthrive soak of the existing roots before potting up our newly acquired bulbs... and it could be that the bulbs are sort of jump started into the production of new roots by its use... but since I don't notice a huge difference, myself, I normally just dust the bulb with a preventative bit of Captan, and pot it up.

I have two bottles of Superthrive... but I confess to not having used them in quite a while!

I do use it for all my bonsai repots after I do a whack-job on the roots. I soak the entire container w/soil to the rim in a ST solution to help stimulate rooting, and it seems to work for that, but I can't seem to find ANY value in it as a 'tonic' - as advertised, even though I've done several side by side comparisons using different plants.

Al

I have not done any comparison tests with Superthrive, so I can't say for sure that it works as a fertilizer booster, either. But I'm inclined to believe you, Al... you have yet to steer me wrong!

I do find that the addition of a micro-nutrient to regular fertilizer does net results, though. New growth comes faster and better than without it. That much, I can say!

I enjoy reading threads like this. It makes me question my preconceived ideas, such as, growth of roots from cuttings starts from the formation of callus cells, which are in fact meristematic cells. Hormones are used to aid in the formation of the callus. Energy stored in the cutting material provides the energy for the root growth. Keeping the cutting in a humid atmosphere prevents energy losses through transpiration allowing more time for root growth to start before the cutting rots. Feeding a cutting has the effect of promoting foliage growth not root formation. Where have I been misled? Al

Callus really isn't meristematic. It's just a mass of parenchyma cells in various stages of lignification (woodiness). That callus forms, often simultaneously with roots and under conditions favorable for rooting, and because roots often emerge through callus, many are lead to believe that callus is essential to root formation, but .....

In easy to root species, callus and roots form entirely separate from each other. In other species, callus might just be a simple precursor to adventitious root formation, while in still other species, callusing can be a hindrance to root formation. It's very common to have roots emerging from several different types of tissue (cambial/phloem rays, fascicles, parenchyma, .......) on the same cutting at the same time.

The first aspect of rooting hormone influence is identified with the acceleration of cell division, especially longitudinal division. The second phase/aspect has to do with promoting a reaction in which root primordia unable to develop further without auxin supply develop into roots. It's influence isn't associated with callus formation.

Al

Al, if I may impose my ignorance...

I did some research this afternoon, but couldn't find an answer to my question; I assume I was looking in the wrong places.

When a cutting goes through the transformation of making roots, what is happening? It sounds like callusing may or may not take place and they may or may not be related to rooting.

I often pull my cuttings out of soil simply so I can watch the process, but I haven't any idea of what exactly is taking place.

I assume you're talking about stem cuttings. In order for this type of cutting to remain viable, they need to form new adventitious root systems. There are 2 types of adventitious roots - preformed & wound induced. Those plants that have preformed root initials may or may not have visible roots before you separate the cutting from the parent plant. Root and leaf cuttings must not only form an adventitious root system, but a shoot system as well.

The formation of roots (and buds) requires the plant to dedifferentiate previously developed cells and redifferentiate them into a meristematic growing point. When you think of a meristematic growing point, think of stem cells, cells that can be transformed into any type of tissue(s).

There are probably 4 steps in new root formation and they would be described as something very close to:

1) Developed (differentiated) cells dedifferentiate
2) Root initials (the first hint the plant is getting ready to make roots) form near vascular tissues which have now become meristematic via dedifferentiation.
3) Meristematic cells organize into root primordia (early cells that serve as the precursors of roots)
4) Additional growth of new roots and their emergence through other tissues at the same time conducting tissues (for moving water/sap/nutrients) make a connection between the root primordia and the and the cutting's vascular tissue.

Al

Oh - I meant to caution you about pulling your cuttings to check on them. The newly formed roots are almost microscopic and extremely fragile, so pulling them to check on them severely damages the roots emerging and recently emerged from primordia. This sets the cutting back considerably & drains energy needed to replace the lost rootage. Cuttings establish much faster if you don't check on them and if you secure them in the media so they aren't subject to movement caused by wind or other forces that can tear/break the new roots.

Al

How I use sugar is by mixing it with cooled down hot tap water pour water in a vase place one freshly cut at 45 - 50 degree stem cut rose of 7 inches and at least five leaves in vase I change water mix every 2-3 days and can get a single rose as described to look fresh up to three weeks in time

The sugar in the water is a short cut to the flower
The leaves also have natural sugars in them but it has to go threw the stem first then to the flower
I can get close to the same results with the same mix even if I had just cut the flower with no stem or leaf and stuck the cutting in a bowl

Destilled water is the best very stable pH neutral pure H20 for it's price.

All leaves do one thing only they conduct Photosynthesis sending there natural sugars and energies to the plant. If the leaf is sick they also feed the plant that illness start your AV. with a healthy leaf for rooting..There is no flower to feed the leaf will have to make a root if not it will die or It will do all it can do to survive, a simple rule of nature.

AV. leaf propagating. Ask in subject line Fred or Barbara how to do in AV. forum they are real good in this area. Keep posting if it goes to deep in pages (or keep looking in them long threads) they will see it one day and will help you even if by links or pics.

SaintPaulina is a toy to me, I cant seem to kill it, even in off growing conditions of soil, fertting, watering ect. It is soon to flower after three months with no flowering (in a day or two) it still looks good enough for me. I wont get into how easy it was for me to get a single leaf from this same AV. to root for me. I opt organic growing manners on all my flowering things. I will share no comments on non organic products in this thread and ask for the same with due respect.

Wesley, in case I wasn't clear I was wondering behind the science behind the role of sugar, not how to root AV leaves in general, but thank you for your thoughtful suggestion. I think the text that Al quoted above cured me of any thoughts I have of using it, though. It doesn't appear to help in any way in research experiments, so it won't play a role in my propagating.

Thank you, Al. I have NO doubt that I should not look at them! Once I figured out the process, I've stopped. I just wanted to see it happening. Now I know, I'm happy to let them do their thing without me peeking.

But, clear soil mix would be really cool!

You CAN root in clear marbles if you want to - or shattered tempered safety glass. Let me know if you really NEED to see roots develop & I'll help you. I actually grew a plant in broken glass for over a year (from a fresh cutting) just to drive home the point that plants don't really care what they're growing in, as long as it provides anchorage, air, and water, they can get nutrients (from us), and is not phytotoxic. Lolol

Al

I already have seen it so I'm fine now :-). Interestingly, the leaves were not worse for the wear. It started innocently, when I first started about 16 leaves. I was carrying them and dropped the container. They all fell out. So, I had to look. Then, a few days later I was having trouble keeping the medium too wet, so I decided to change how I did it (large container to individual. So, had to look again. After that, they just kept growing and I kept looking until they had established roots.

Interestingly, every one of that first batch produced and I have plants from them all now. I was exceedingly careful (except when dropping them) but African Violets must have a bad rap, lol, given those all withstood my curiosity and survived.*

*actually, they do have a bad rap. They are not hard to grow at all, they simply have a very narrow range of water requirements. Traditional soil less mixes are the death of them if you do more than sprinkle the mix! But, it's not the plant's fault; it's the mix' fault.

I think adding sugar, or an apirin, or bleach... or even the packet they give you with long stem roses... to the vase of water, is designed explicitly to prolong the bloom and the turgidity of the stem holding the bloom... and/or to keep the water fresh so the stem can "drink"... not for any other purpose. It has nothing to do with rooting them.

Personally, I have found that taking a fresh, slanted cut to the stems of cut flowers, and changing out the water daily, helps keep bouquets looking nice as long as possible. But they are only cut flowers, and they will eventually die.

For rooting cuttings, I find that the main ingredient necessary is patience!

I recently did twin scaling on a bulb to save its life... it was rotting between several of the layers. I cut the bulb into quarters, cutting out as much rot as possible, and keeping a portion of basal plate attached to each quarter (necessary for root development).

I dusted the bulb pieces with anti-fungal powder, and placed them in moist vermiculite in plastic ziploc bags. I kept the baggies on a heat mat, using a plastic bowl cover for a heat buffer, and waited for roots and new bulblets to form.

It took a very long time! I neither moved the baggies around, and I didn't open them at any time. It took oodles of patience! Finally, after months of waiting, new green bulblets appeared, and I turned on the overhead grow lights. The bulblets eventually grew their own leaves, and at that time, I removed them from the baggies and potted them up in Al's Mix.

Here are the bulblets when newly potted...
{{gwi:53197}}

And here are the bulblets forming inside the bag...
{{gwi:53198}}

Here they are when first bagged...
{{gwi:53199}}

The pieces when cut...
{{gwi:53200}}

And finally, the rotting bulb, itself...
{{gwi:53201}}

The progression is posted backward... and it really doesn't mesh with the discussion... except for one huge detail!

PATIENCE!

Patience is probably the biggest factor in rooting cuttings... Al laid out the technical, scientific facts... and I just wanted to add that, fungal issues notwithstanding, I don't think there's really a need to use anything chemical to obtain roots. But patience is necessary, and if you leave the cuttings alone and simply wait, most plants will reward you with roots!

Ok... I'll shut up now... I'm off to check my pots for moisture... :-)

No need to shut up...Jodik..I love hearing you speak!

You are soooo right..

In fact I have a friend that likes to colon his plants with some sort of machine, and the only things he says that he uses is "distlled water" as Al says, and a whole lot of oxygen, from constantly moving water. The water is very much oxygenated...

There is a couple products that he uses from a hydroponics store to help the roots along at a much quicker pace..

Power cloner and Clonex solution...Not sure what they consist of or if you can just use in a glass of water, but this stuff certainly works well in the machine and gives him alot of success..Along with PATIENCE...

Mike..;-)

Rooting in water is actually a pretty inefficient way to clone plants. It may be 'easier', but if it was 'better', it would be the preferred method of commercial propagators; but practically speaking, none use it. It's that whole 'better for the grower than the plant' thing again.

Al

Unbeleivable Al....Go figure ha?

:-)

Thank you, Mike... you keep up with the compliments, and I'm gonna get a big head! ;-)

I have often wondered how plants were commercially cloned... but just have never looked it up. I know orchids are cloned quite regularly, and I'm sure bulbs and other plants are, also. I know that a sterile environment is necessary... but beyond that, I don't know much.

I have always propagated through cuttings, root divisions, or offsets, and more recently, I've begun breeding certain plants through selective pollination. I've pollinated my Hippeastrum flowers, and I've been successful obtaining viable seed. I've also pollinated a few Daylilies, and I've got seeds from those, too.

Growing the seeds to flower takes an awful lot of patience, as well... it takes roughly 3 or more years to see flowers from the seeds of Hippeastrum... 2 years in ideal conditions... and I think it's about the same for Hemerocallis, or Daylily.

I hear orchidists refer to Clonex, though I'm not really certain how they're using it. I assumed it was to help grow new roots on rootless orchid pieces.

But laboratory cloning of plant material is something I don't know much about.