Any plant that is transplanted will suffer some degree of shock. Put it in the shade for a day or 2. then into half sun for a week

it has been 3 weeks already, with no sign of recovery, just slowly losing leaves, that's why I am concerned

Sorry about the issues you're having. The medium appears very course, so it's important to make sure you maintain a sense of where the roots are located in the soil column and the medium stays moist where the roots are until the plant reestablishes. Given how coarse it is, it would be very difficult to over-water, so be sure to water as often as needed to keep the entire soil mass (except perhaps for the top 2-4cm). Also, keep fertilizing, maybe at a higher rate. If they provide a production rate and a maintenasnce rate, use the production rate every 3rd time you water (as long as you flush the soil as you water). Tying the fertilizer frequency to the number of times you've watered is a better management strategy than using the calendar. If you're concerned you'll forget when it's time to fertilize, drop a marble, button, bottle cap, ..... in the pot when you water. When you're about to add the 3rd item, fertigate (water+fertilizer) instead and remove the 2 items from the pot. If the 6-4-6 doesn't have magnesium, use that for now. Basalt is very high in Mg and can affect Ca uptake. I'm not suggesting that's what's occurring, just providing cautionary information. A soluble synthetic fertilizer will work best and give you the most control. If you can find a product like Foliage-Pro 9-3-6,

use that. Look for fertilizers in a 3:1:2 or 2:1:2 RATIO. A fertilizer's RATIO is different, and more important) than its NPK %s. 3:1:2 ratio fertilizers would be something like 24-8-16, 12-4-8, or 9-3-6. 2:1:2 Ratio fertilizers would be something like 20-10-20, 18-9-18, or 6-3-6. The key to Foliage-Pro 9-6-6's popularity lies in the fact it has ALL nutrients essential to normal growth, in the ratio at which the average plant actually uses the nutrients (a significant advantage), and it derives more than 67% of it's nitrogen from nitrate sources. ..... not sure if you have something similar there, but you might ask at a hydroponics store.

If I had to guess what occurred to cause the plant's rebellion, it would be that the mix is very course and you didn't go far enough in shortening the watering intervals, which causes loss of some of the fine rootage. It might be helpful to notch a plastic plate around the trunk so it covers the pot and slows evaporative water loss from the soil surface until the plant bounces back. It's not uncommon for first-timers to be met with some sort of a setback the first time they do a full repot; but usually when the plant bounces back, they find the difference it makes in plant performance makes it worth it. Too, as you become more accustomed to rootwork and fully repotting, you'll find your plants hardly notice your benign intrusion into their root systems.

Best luck. Let me know if you have further questions you think I might be able to answer.

An afterthought: Even in view of the setback it's almost a certainty that if the plant pulls through, within just a few weeks it will have grown larger than had you simply potted up or left the plant in the same pot, and will be enjoying a much higher level of vitality (health).

Al

Citrus uptakes fertilizer at a 5-1-3 ratio. Jacks high performance 25-5-15 is a great fertilizer for container citrus as well as the previously mentioned foliage pro 9-3-6.

Someone needs to tell Jack right away. The silly guy has labeled his 2:1:2 ratio fertilizer 20-10-20 as their citrus blend. From their boiler plate: "Citrus FeED 20-10-20 is designed to provide the optimum combination of nutrients needed by plants in the citrus group." Please provide an explanation.

Al

I fully agree with Ken B on the point that citrus uptakes NPK nutrients in a 5-1-3 ratio. For anyone who wishes to understand why this is so their is a excellent description of the 5-1-3 nutrient uptake of citrus in the textbook titled THE GNIUS CITRUS.

So you're saying on average the citrus genus uses/ takes up 5X more N than P and 3/5 as much K as N?

Al

Al, as I wrote you can read how they determined the 5-1-3 ratio in the text book THE GENIS CITRUS

That's a very simple question, but you won't answer it. Interesting. Ken? Give it a shot?

Al

Thank you @tapla (mid-Michigan, USDA z5b-6a) for the valuable detailed information and thanks everyone for the helpful answers :)

I really appreciate the time and effort taken to address the questions, hope you don’t mind a few more :)

I will increase the fertilizer to full does and up the watering frequency and hopefully give an update with recovery soon

Regarding the fertilizer, Foliage pro is not easy to get here but I happen to do hydroponics as well, so I have few bottles of GHE tripart laying around (Flora grow, Flora bloom, Flora micro) (picture below) it contains all the micro nutrients and I can try to mix it to get the 2-1-2 or 3-1-2 ratio, would that be a good idea ? i also generally mix seaweed with fertilizing water at low dose 1ml/L

I have a universal 7-3-6 fertilizer without calcium, and a slow release 6-3-5 fertilizer (with dosing instructions per area, i never managed to figure out how to convert that to per volume of soil given that the containers i have vary significantly in depth)

Is it recommend to mix slow release in gritty and if so how to calculate how much based on the N-P-K or is there a general rule of thumb

Regarding the water I use, the analysis shows it is very hard with pH of 8 and contains calcium 80mg/L and Mg 21mg/L and a total hardness grade of 16dh, I use citrus acid powder to adjust the pH down to 6, but given the calcium content in water, do I really need to worry about adding calcium ? Or epsom salt for the Mg

Finally, I wanted to ask whether if there is some instructions/tutorial (preferably video) or related to repotting in gritty mix or repotting/root trim in general

many thanks !

Fahmy

Thanks for the kind words, Fahmy.

I have few bottles of GHE tripart ..... [which] contains all the micro nutrients and I can try to mix it to get the 2-1-2 or 3-1-2 ratio, would that be a good idea? Yes. Where I headed if you replied was in the direction of using a K supplement to add to your 3:1:2 or or 2:1:2 fertilizer. Here, we have a product that contains 3% (0-0-3) potassium and opalene silicon which is is a great additive. That it makes cell walls extra strong so they can resist insect herbivory and disease pathogens, and increases the plant's resistance to heat, cold, over-watering, and drought are among its several benefits. As I noted, most reliable sources suggest that citrus is supplied at least as much potassium as nitrogen, and slightly more would be better. Florida State University suggests a 1:1.3 ratio of nitrogen:potassium respectively.

I have a universal 7-3-6 fertilizer without calcium, and a slow release 6-3-5 fertilizer (with dosing instructions per area, i never managed to figure out how to convert that to per volume of soil given that the containers i have vary significantly in depth). Fertilizers are formulated so the most efficient use of nutrients occurs at a specific concentration, so those who practice fertilizing at half or some other fraction of the suggested solution strength are sacrificing a lot of potential growth and vitality because they are afraid to overdo. Most hobby growers substantially under-fertilize their plants. Case in point: i have about 200 trees in pots. I try to fertilize every weekend unless mean temperatures are below 15* or above 27*C, and I use slightly more than twice the recommended production dose w/o issue and very good results. The lesson, I think, is that label instructions will always err by far on the safe side.

Typically, I make sure there is moisture in the medium before I fertilize. My habit runs to watering early in the day and fertilizing late in the day. I apply the solution evenly across the top of the soil and stop when I see solution exiting the drain hole, I stop. I haven't seen it suggested anywhere that you should try to calculate how much solution you should apply on a per volume basis.

Is it recommend to mix slow release in gritty and if so how to calculate how much based on the N-P-K or is there a general rule of thumb? Its very common to conflate slow release and controlled release products. Slow release is something that is marginally soluble and usually incorporated into the medium at potting time. It would usually be similar to the fertilizer you might apply to a lawn or garden. Controlled release products have a water permeable coating that allows small charges of fertilizer to be released regularly. They are usually sold as 3-6-9-12 month products and release rate is usually driven by temperature. Which product are you asking about? I have never mixed slow release into or broadcast it on top of the gritty mix, but I have done both using a controlled release products, though I use them sparingly. Reason: When it gets hot in summer, and growers should be pulling back on fertilizing, controlled release products are releasing nutrients at maximum levels. I prefer to have good control over what plants get and when they get it.

Regarding the water I use, the analysis shows it is very hard with pH of 8 and contains calcium 80mg/L and Mg 21mg/L and a total hardness grade of 16dh, I use citrus acid powder to adjust the pH down to 6, but given the calcium content in water, do I really need to worry about adding calcium ? Or epsom salt for the Mg. Not at those levels, and the ratio of Ca:Mg is appropriate, so there should be no concern about antagonisms between Ca and Mg.

I wanted to ask whether if there is some instructions/tutorial (preferably video) or related to repotting in gritty mix or repotting/root trim in general Not that I know of ..... at least I haven't made one. When you're ready to repot your next plant, look me up and we'll go over it in more detail.

You might find this thread about long term care of Trees in Containers to be useful.

Al

Hi Al,

Many thanks again for the detailed answer, I really appreciate the time and effort !

Here, we have a product that contains 3% (0-0-3) potassium and opalene silicon which is is a great additive

Thanks for the advice, I do have a bottle of "vitalink silicon max"/potassium silicate, the contents list Potassium (K2O) 6% and soluble silica as SiO2 6%, the recommended dose is 1mL/L weekly so I will start including that

Which product are you asking about?

thanks for the clarification, the one I have is certainly slow release, here in germany, there is usually an additional distinction that the fertilizer is "coated" to indicate it is a CRF

I have never mixed slow release into or broadcast it on top of the gritty mix

are there disadvantages, I do not know whether slow release fertilizer release rate is affected by temperature like CRF, I am asking because I have always mixed slow release when preparing soil mixes, sorry I was not clear, my question regarding the per volume fertlizing was related to how to calculate the amount of slow release per volume of soil

When you're ready to repot your next plant, look me up and we'll go over it in more detail.

Thank you for the kind offer :) , I will certainly do

You might find this thread about long term care of Trees in Containers to be useful.

I went through the thread, very useful, I would like to learn more, do you have recommendations for container gardening books

- I have an additional question, have you heard about "lechuza pon" ? it is an inorganic coarse substrate (zeolites, pumice and light lava)which is very similar to gritty mix,

could it be used as an alternative to gritty mix, it is marketed as highly aerated (55%) alternative to soil, but at the same time it is recommended to be used with the lechuza pot, which is a self-watering pot being watered through a reservoir at the bottom, could a highly aerated mix use wicking for watering? and what would be the other factor for the wicking effect here, maybe similar to Leca which is also very coarse yet wicks water

Thanks,

Fahmy

I'm also interested in hearing Al's (and other gritty mix experts') take on lechuza pon.

I've been reading everything that I can get my hands on about Al's gritty mix for the last few weeks. The science makes sense and I'm all in. Because I live in Germany, I cannot easily access certain ingredients (e.g. Turface). I recently made a gritty mix with lechuza pon, seramis, and sifted pine bark in a 1:1:1 ratio. Because I substituted pon for the cherry stone, I suspect that my gritty mix may retain more moisture than the original recipe, but after pouring over Al's (and others') thoughtful and detailed explanations, I think that my mix should work from the standpoint of perched water and root aeration because of the particle size (everything in my mix is between 3-8mm and 1/3 of the mix is organic in the form of pine bark). In making this mix, I also embraced Al's comments that understanding the concepts behind the mix is more important than the specific ingredients of the mix. I've been transitioning all of my plants to my mix and, although it is still early days, they are doing very well. I'm currently working up my nerve to bareroot and repot my lemon tree into my gritty mix (it's the last plant that I need to repot into the mix).

Because they already have the appropriate particle size and therefore do not require sifting, off-the-shelf products like lechuza pon and seramis have the potential to save a lot of time and hassle, especially for people who live in city apartments (I do a lot of repotting in my bathroom, haha). From my understanding, you do not have to use the lechuza pon with the lechuza pot (I think that it even says on the lechuza website that the pon can be used as a soil substitute). As an experiment, I have a jade plant and another small succulent in 100% pon (in a normal pot with drainage), and they are thriving. I'm toying with the idea of moving them to 2:1 mix of lechuza pon and sifted pine bark, but I'm not sure if it would provide any advantage to add the pink bark. Another question is whether to put these plants in my gritty mix, but I don't think that they would necessarily benefit from the added seramis and therefore (what I assume to be) increased moisture retention (the pon already seems to hold a perfect amount of moisture for them). Lastly, I wonder whether 2:1 mix of lechuza pon and pine bark could be a substitute for the gritty mix full stop. Al (or any other gritty mix experts out there), do you have any thoughts on this?

In case this is helpful for Fahmy: for fertilizer, I'm using Growth Technology Formulex Nutrient Solution as German-available substitute for Foliage Pro. It's nutrient profile is supposedly similar to Foliage Pro.

I'm still working to understand the details of fertilization. Once I repot my lemon tree in gritty mix, I'm uncertain if I need to increase the amount of fertilizer for my lemon tree or just give it the same amount of GT Formulex (5ml/L) as I do for my other plants (I'm operating under the assumption that my lemon tree is a heavy feeder, but I don't want to overfeed it either). Does anyone have thoughts about this? Since my lemon tree is still in soil, I'm currently using a weekly citrus-specific fertilizer from Meine Orangerie (18.5-5-15 ratio). I'd love to use that fertilizer up even after I move my lemon tree to gritty mix, but I don't think that it has a complete nutrient profile. Maybe I can alternate watering with the GT Formulex and Meine Orangerie? If anyone has thoughts/opinions about these questions, I'd love to hear them!

Thank you to everyone for the discussion and advice. Even though it is meant to help Fahmy, it's also very helpful for me, and I appreciate all of the time and effort.

@Fahmy Glads you found the info/suggestions useful.

Good to know you have the soluble silicon/potassium supplement there. There are a fair number of plants that would appreciate a little more potassium than supplied in 3:1:2 ratio fertilizers, Citrus being one group, so the 3:1:2 fertilizers offer that flexibility

..... are there disadvantages [to using controlled re, I do not know whether slow release fertilizer release rate is affected by temperature like CRF, I am asking because I have always mixed slow release when preparing soil mixes, It depends on what fraction of the fertilizer product is in the form of organic soil amendments, like various meals (hoof/ horn/ blood/ alfalfa/ cottonseed). Soil bio activity slows dramatically at about 30*C, which would decrease release of nutrients locked in hydrocarbon chains (much of the nitrogen); however, water solubility increases as temperatures rise, so availability of soluble nutrients would increase as temperatures rise.

I would like to learn more, do you have recommendations for container gardening books? Most books authors publish through vanity press arrangements really don't get into the science of growing in a pot. I have a few of those types of books, but they're pretty much useless as a reference.

Plant Production in Containers II is an excellent text which is strong on the 'growing' aspect, but provides little in the way of understanding how plants actually work. That comes from sources focused on physiology and morphology. The text's I learned the most about the 'how' part of growing are Plant Production in Containers II ~ Carl Whitcomb PhD, Growing Media for Ornamental Plants and Turf ~ Handreck & Black, and A Grower's Guide .... Water, Media, and Nutrition for Greenhouse Crops (ISBN1-883052-12-2), not in that order. The later of the three is published by Ball, edited by David Reed, and is the text I used to refer to most frequently.

I own a number of texts that focus on physiology/ morphology, all of them excellent.

Plant physiology ~ Taiz/ Zeiger and Plant Physiology ~ Mohr/ Schopfer, are both great books and can answer nearly all your questions re how plants work, but they are tough sledding. The physiology of woody plants is very well covered in Growth Control in Woody Plants and Physiology of Woody Plants, both works of Pallardy/Kozlowski. Information re propagation and pathology will really round out your understanding of how plants work, and Marschner's Mineral Nutrition of Higher Plants is definitely the 'bible' when it comes to plant nutrition.

There is a book called Botany for Gardeners by Brian Capon. It is a very good book and explains the basic functions and processes at a very reasonable price. ISBN-13: 9781643261430

..... have you heard about "lechuza pon"? Yes, I'm familiar with it.

..... could it be used as an alternative to gritty mix, it is marketed as highly aerated (55%) alternative to soil, but at the same time it is recommended to be used with the lechuza pot, which is a self-watering pot being watered through a reservoir at the bottom, could a highly aerated mix use wicking for watering? There is no reason it shouldn't serve well as a medium similar to or maybe even equal to the gritty mix (GM), as its construction seems to be based on the same concept that gave rise to the GM. I don't think it will serve as well in a wicking situation as it would if watered from the top.

Wicking depends on the capillary 'pull' of the medium being stronger than the force of gravity. The sum of the forces of water's tendency to stick to itself (cohesion) and to stick to other materials (adhesion) = capillarity. Particle size drives water retention because a jar of sand has far more surface area than a jar of marbles, and more surface area + more adhesion + greater capillary pull. Because the gritty mix and Lechuza Pon (LP) are made of particles screened to deny excess water's ability to perch in the pot, their wicking ability is very limited. Any wicking would require water movement into the internal pores of a porous particle, and the water then being pulled upward into another porous particle higher in the soil column. Unless there are enough porous particles with very significant capillary pull, water will reach a dead end (no contact with another porous particle higher in the soil column) within the first inch above the surface of the water in the reservoir. You should be able to evaluate if LP's wicking ability is adequate.

..... what would be the other factor for the wicking effect here, maybe similar to Leca which is also very coarse yet wicks water. Leca works as I just described, but because the Leca spheres will always be in contact with another sphere higher in the soil column, and the low-fired clay has a great deal of capillary 'pull', the spheres will (collectively) have a great deal of capillary pull.

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

@HU-504793490 - I read what you shared. If your citrus is potbound, It would be better to chop off the bottom of the roots and trim a bit of the soil away from the circumference of the root mass instead of a full bare-root/repot in June. While most houseplants are best repotted in June, including tropical trees, Citrus should be repotted in early spring. I'm making a distinction between repotting, which includes rootwork, and potting up, which can be done at any time of year without the tree complaining much. March and April (in the Northern Hemisphere) are good for repotting while the best time to pot up would be April and May.

Once I repot my lemon tree in gritty mix, I'm uncertain if I need to increase the amount of fertilizer for my lemon tree or just give it the same amount of GT Formulex (5ml/L) as I do for my other plants (I'm operating under the assumption that my lemon tree is a heavy feeder, but I don't want to overfeed it either). You'll need to fertilize more often with the gritty mix because wetting the soil column fully means a fair amount of water will flush through the soil. While plants are growing and temperatures allow, I try to fertilize weekly at at least the recommended dosage for production (highest suggested rate). Typically, I use about 1.5x the production rate, weekly.

Since my lemon tree is still in soil, I'm currently using a weekly citrus-specific fertilizer from Meine Orangerie (18.5-5-15 ratio). That seems a bit high in N, but that meshes well with a medium like the gritty mix as N is most readily leached from the medium through watering.

I'd love to use that fertilizer up even after I move my lemon tree to gritty mix, but I don't think that it has a complete nutrient profile. Maybe I can alternate watering with the GT Formulex and Meine Orangerie? If anyone has thoughts/opinions about these questions, I'd love to hear them! If you can provide the list of nutrients your fertilizers contain (In English), I'm sure we can come up with a plan.

Al

@tapla (mid-Michigan, USDA z5b-6a) Thanks for your response! I really appreciate you taking the time. I have learned so much from your many posts, and they have taken my knowledge and skills to the next level. I know that I still have a lot to learn, though!

Thank you for the tip to repot my citrus plant in March/April. Unfortunately, the plant is root bound in its nursery pot. Since May has just passed, do you think that it would be okay to carefully bare-root and pot it up into gritty mix asap (while putting off the real rootwork until next March/April)? Outwardly, the plant appears healthy and strong.

In terms of fertilizer, I recently bought Growth Technology Formulex Nutrient Solution:

The Meine Orangerie fertilizer has the following profile (via Google translate):

Total nitrogen: 18.5%
- Nitric nitrogen: 7.9%
- Ammoniacal nitrogen: 10.6 %

Phosphate: 5%
Potassium Oxide: 15%

Magnesium Oxide: 2%

Trace elements:
Boron (B) 0.020
Copper (Cu) 0.030*
Iron (Fe) 0.200**
Manganese (Mn) 0.075*
Molybdenum (Mo) 0.001
Zinc (Zn) 0.050*
* as a chelate of EDTA
** as chelate of DTPA+ EDDHA

How does the GT Formulex look to you? It's the closest thing that I have found to Foliage Pro so far. I haven't opened it just yet and could still return it, if necessary. An issue that I can see with the Meine Orangerie fertilizer is that it lacks calcium. Can I try to use it up, perhaps alternating weeks with a more well-rounded fertilizer?

I would also like to add a silicon supplement for my plants. From other posts, I recall you mentioning that you do not adjust your pH when you fertigate with Pro-Tekt, and a representative from Dyna-Grow said that it was not necessary to adjust pH when using Pro-Tekt with Foliage Focus because the pH of latter is enough to offset the former (please correct me if I misunderstood something here). If I add a silicon supplement like the one that Fahmy mentioned (soluble silica as SiO2 6%: http://www.vitalink.eu/additives/silicon-max/) or Growth Technology Liquid Silicon (potassium silicate 6%: https://www.growthtechnology.com/product/liquid-silicon/) to my weekly fertilizer regimen and the instructions for the supplement say to adjust the pH down, do I need to follow those instructions or can I skip that step (as if I was using Foliage Focus and Pro-Tekt)?

Thank you again!

Pretty low on nitrogen for citruscitrus with the formulex, the meine would definitely be better for citrus.

@Ken B Zone 7 There are a number of considerations involved in determining which fertilizer of the 2 is most appropriate. On what did you base your opinion, Ken?

@HU-504793490 - I'm a firm believer in bare-rooting and root pruning at repotting time, but I also am familiar with what can happen when a repot is done out of season, so I adhere pretty rigidly (where my own trees are concerned) to the idea that a full repot out of season is very risky. I have done them from time to time, but always with a hard top pruning at the same time so the entire organism won't collapse due to a demand for water to the canopy that roots can't keep up with. Normally though, my strategy is as I described above. Do a little perimeter root pruning and pot up until a more appropriate time. Of course, it's your call, but I'm thinking it's not a good idea to take unnecessary risks during your first repot. I considered both scenarios (repotting w/o root pruning and potting up with some cursory root work, and my experience forces me to say the later is the best of the two choices.

I've been really short of time (and sleep) lately, so I likely won't be back to answer the rest of your questions until later tomo or Fri, but I won't forget.

Al

@tapla (mid-Michigan, USDA z5b-6a) Thank you for your explanation! It helps me better understand your recommendation. I am impatient to get my citrus into the gritty mix, but I will take your advice: do some minimal perimeter root pruning and pot up. Next March/April, I'll tackle the bare-rooting, etc. I needed to adjust my timeline to tree-time. :)

Yesterday, I dove deeper into fertilizer options and found one more possible contender that contains calcium and magnesium. It's called Compo Complete (from what I can tell, Compo is sort of like the Miracle Gro brand in the US). Here are the specs:

6% N total nitrogen
- 4.5% N nitric nitrogen
- 1.5% N ammonium nitrogen
4% P2O5 water-soluble phosphate
6% K2O water-soluble potassium oxide
2% MgO water-soluble magnesium oxide
2% CaO water-soluble calcium oxide
0.014% B water-soluble boron
0.003% Cu water-soluble copper chelated by EDTA
0.093% Fe water-soluble iron chelated by EDTA
0.013% Mn water-soluble manganese chelated by EDTA
0.0013% Mo water-soluble molybdenum
0.003% Zn water-soluble zinc chelated by EDTA

Low in chloride

To clarify (in case it may shape your response), my primary goal is to find one kind of fertilizer plus a silicon supplement that I can use for all of my houseplants when I water them (like the Foliage Focus and Pro-Tekt combination). I would like to have the simplest routine possible (partly because I need to entrust my routine to someone else when I travel). At the same time, I am willing to take extra steps (e.g. adjusting water pH or mixing fertilizers to get the right NPK ratio) if there is significant upside. Secondarily, I would like to be able to use up the Meine Orangerie (let's call it MO) fertilizer, but if it isn't going to work, I am willing to eat the cost as part of my learning experience. I am also willing to use MO exclusively for one plant, e.g. my citrus, until it is used up while using a different fertilizer for my other houseplants (peace lily, ficus elastica, ficus benghalensis, laurus nobilis, spider plant, monstera adansonii, zz plant, dracaena marginata, aglaonema, jade, sansevieria) or alternate weeks with the MO fertilizer and another fertilizer.

Al, I completely understand if you cannot respond right away, so no worries! I am reassured that you won't forget. :) Thank you again!

Stress caused citrus to flower. Flowers is how the tree reproduces so when stressed it tries to reproduce to keep the generations going.

Stress didn't cause the blooms to open. To some degree, some stress factors can increase the number of blooms produced by a plant, but too great a stress factor typically causes regression - less of everything. As long as the tree is alive, and whether it has leaves on it or not, the plant will bloom when it's ready. Blooms don't require a current supply of photosynthate (food) to open because there is a grain of glucose polymer (starch) at the base of each bloom bud, already bought and paid for. All that the plant needs for the blooms to open is a source of water and the means to transport it to the base of the bloom bud. The plant does the rest. This is made apparent by the multiplicity of plants that bloom in winter or early spring before a single leaf has been produced.

Al

so, on the positive side, the tree is still alive :) and as there are bloom buds opening at the tips of the branches, it seems there was no die back !

I will stick to fertilizing every 3rd time at full rate and hope to see some leaves on the branches and a full recovery soon

Thanks everyone for the valuable inputs,

Fahmy

I wanted to get back to everyone's questions sooner, but we had a birthday party for my youngest son and we had people from all over the country in town for several days, so I only had a few short opportunities to keep up with what's going on here at GW.

@HU-504793490 From your first paragraph in your post above, I can tell you've been doing some reading.

I dove deeper into fertilizer options and found one more possible contender ..... my primary goal is to find one kind of fertilizer plus a silicon supplement that I can use for all of my houseplants .....

The fertilizer you listed above is probably ok for your plants and appropriate for using the potassium/silicon supplement, but it does contain about twice as much phosphorous as the plant will likely use. Phosphorous (P) is iron's (Fe) primary antagonist, meaning excess P can limit the plant's uptake of Fe. The clue that there is a problem with P would likely be in the form of interveinal chlorosis. If you see that and you are keeping up with the necessary frequency/rate of applications, you'll probably need to look for something with less P. If I was in your place, I'd try it.

Secondarily, I would like to be able to use up the Meine Orangerie fertilizer, but if it isn't going to work, I am willing to eat the cost as part of my learning experience. It Given it's contents, it should work fine with fast-draining, well-aerated media. If your main focus is to use it up and avoid waste, use it for the plants that get the most light. There is greater potential for excessively long internodes when the combination is low light with high N - much less of a problem in high light situations, which tends to shorten internode length.

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

@Fahmy who said "i noticed my citrus (acrobal) is pushing a couple of new flower buds! It is a bit unexpected as it hardly have any leaves left on the branches ! I am not sure if this is a good sign of recovery or what is happening ..... It's a good sign in that it reveals the plant has energy enough to take up water and nutrients and deliver both to the plant's distal parts. That means the root system is functional and vasculature still unobstructed by fungal invaders. The key factor is whether or not the plant has enough energy to support at least a few leaves to the break even point. When new leaves are about 75% mature, they turn from net users of energy to net producers of energy, so it would be something of a tipping point. I'm very glad to hear your plant seems to be doing better. Strong work!

Al

Thanks for getting back @tapla (mid-Michigan, USDA z5b-6a)! I will use up the MO fertilizer for my plants getting the most sunlight, like my citrus. I can also keep an eye out for interveinal chlorosis (thanks for the explanation about that). If you don't mind, I have two quick followup questions:

1. Between GT Formulex and Compo, which fertilizer would you recommend for general use (or should I keep looking for a better option altogether)? I already bought the Formulex but can return it if the Compo is preferable. So that you don't have to go back through my posts above, here is the Formulex:

And here are the specs for the Compo:

6% N total nitrogen
- 4.5% N nitric nitrogen
- 1.5% N ammonium nitrogen
4% P2O5 water-soluble phosphate
6% K2O water-soluble potassium oxide
2% MgO water-soluble magnesium oxide
2% CaO water-soluble calcium oxide
0.014% B water-soluble boron
0.003% Cu water-soluble copper chelated by EDTA
0.093% Fe water-soluble iron chelated by EDTA
0.013% Mn water-soluble manganese chelated by EDTA
0.0013% Mo water-soluble molybdenum
0.003% Zn water-soluble zinc chelated by EDTA

I'm asking this question for not only a practical reason (to select the best available fertilizer for general use for my houseplants), but also to increase my knowledge of how to evaluate fertilizers. (For instance, Formulex has additional micro-nutrients like cobalt, sulfur, and nickel while Compo doesn't--does that matter here?)

2. If the instructions for my silicon supplement recommend adjusting the pH down, it it necessary to do that? Or can I safely use it in the same way that you use Pro-Tekt? I'm willing to take the extra step of adjusting the pH if there is significant upside, but I'm also trying to keep my watering routine as simple as possible.

Thank you again for your advice. It's a privilege to pick your brain!

@Fahmy So glad that your citrus is showing some positive signs, and I hope that it will start pushing out new leaves soon! :) The warm sunny weather that we're having right now should hopefully help!

Between GT Formulex and Compo, which fertilizer would you recommend for general use (or should I keep looking for a better option altogether)? Most hobby growers, probably 80-90%, lack a working knowledge of how to best provide for their plant's nutritional needs. It's probably close but not as high as the % of growers who think roots will immediately forfeit their viability, and I might as well include an appropriate grow medium and sound watering practices on the list of vital parts of a care regimen if you do anything to mess with them. Full repots rather than potting up, and a sound nutritional supplementation are both critical to the grower's ability to maximize their plants' opportunity to realize as much of their genetic potential as possible.

Between the two fertilizers, I'd choose the Compo 6:4:6 as the one likely to cause the least issues; however, I don't think either of them are appropriate to be used in combination with a silicon/potassium supplement, or, for use with grow media that use coir or CHCs as a major fraction of the medium. Reason: Coir has a very high potassium content that needs to have a work-around in place for best results, so you shouldn't use either fertilizer or the potassium/silicon supplement in combination with coir or CHCs, nor should dolomite be used as a liming agent due to coir's high pH.

I'm not sure if you have seen this piece on Fertilizing Containerized Plantings. It should be helpful.

If the instructions for my silicon supplement recommend adjusting the pH down, it it necessary to do that? Or can I safely use it in the same way that you use Pro-Tekt? The pH of silicon is pretty neutral (6.5-7.5) but the pH of potassium compounds are very alkaline, but that fact is offset in that small amount used in comparison to the amount of most acid-forming fertilizers makes it mostly a non-issue. This is a direct quote from an email conversation I had with Dave Neal, CEO of Dyna-Gro Nutrition Solutions:

"Because silicon, like calcium, is a non-translocatable element, optimum benefits require regular applications in growing plants to insure that the new tissue obtains soluble silicon. Benefits provided include increased resistance to fungi, insects, low light levels, increased mechanical strength and less reliance upon osmotic pressure for leaf turgidity (longer between waterings). While silicon is incorporated in the cell walls, the principal benefits come from the deposition of silicon in an opalene form in the epidermis of leaves and stems. This mechanical barrier deters many insects as it makes the leaves too tough for insects to feed upon.

To date more than 200 university studies have been published regarding the multiple benefits of soluble silicon. If you are using distilled water, presumably you are adding fertilizer. Since most [fertilizers] are acidic and applied at a rate higher than Pro-TeKt, the fact that Pro-TeKt has a high pH is more than offset by the low pH of the fertilizer. With many thousands of long time users of Pro-TeKt, I know of no one who has lost a plant due to high pH."

Al

Tapla I am probably in the 80% to 90% that don't have a good working knowledge of caring for my citrus plants.

Steve

@poncirusguy6b452xx I'm not sure how to read what you said. I didn't intend it as a pejorative statement, only to impress on the person above who seeks a better understanding of nutritional supplementation that (s)he's not alone. We're all scattered somewhere along the scale of understanding and far from the top, including me, and I have no problem willingly admitting that.

Al

I will say it's been a rough ride.

Do you have an idea of where the problem(s) is/are? Underlying most issues is a root system not performing to its potential, and that is often the result of a less than ideal medium and watering habits that that are mutually antagonistic. Even insect infestations and diseases are very often the result of the stress and inhibited metabolic processes caused by limited root function.

Do you live where growing citrus outdoors is realistic?

Al

@tapla (mid-Michigan, USDA z5b-6a) Thank you for your feedback! I've reread your post on fertilizing containerized plantings. I'm not using coir or coconut husk chips, so that's not an issue in my case (but good to know nonetheless).

I'm determined to find a great fertilizer for my plants. After the time and effort that I invested in learning about, sourcing ingredients for, and repotting my houseplants into the gritty mix (minus the citrus plant, which will wait until next spring), I don't want to come up short when it comes to my plants' nutrition. In other words, I didn't just go through all of that effort with the gritty mix to not try to maximize my plants' genetic potential! :)

In case it helps anyone else in Europe struggling with sourcing fertilizer similar to Foliage Pro, PLNTS.com has an NPK 6-2-4 fertilizer including calcium and magnesium with the following specs: N Nitrogen 5.50 %, P2O5 Phosphorus Pentoxide 1.70 %, K2O Potassium oxide 4.00 %, CaO Calcium oxide 4.30 %, MgO Magnesium oxide 3.20 %, and additional trace elements: Iron (Fe), Manganese (Mn), Zinc (Zn) and Molybdenum (Mo). Maybe I'm not looking in the right places, but after many hours of searching, it's the closest thing that I could find.

I almost bought the PLNTS fertilizer and called it a day, but in the end, I decided to import Foliage Pro 9-3-6 and Pro-Tekt from a hydroponics shop in the UK. The shipping cost was about the same as the cost of both products combined (ouch) and I still have to pay VAT. It's an expensive choice, but I don't have 100+ plants, so these products (each container is aprox. 1L) should last me many years, thus spreading out the cost. I wanted something proven that would give me peace of mind.

Thanks again Al. And Fahmy, I wouldn't have had the courage to post here if I hadn't seen your post, so thank you for that (and making room for me in this thread)!

@bluebelle_7a_germany What a helpful post, and a valuable one for our European friends.

I can see what you meant about the time and effort. I'm not sure why the site makes it so difficult to find the fertilizers nutrient %s, but I finally found them. That product IS a 3:1:2 ratio fertilizer, and it contains all of the nutrients likely to be missing from most substrate ingredients. Thanks for you're efforts. I'll figure out a way to save the info so I have it at my fingertips, because this question comes up frequently. Great find - thank you!

Al

My problem iswith little light at ground level so my citrus trees are on my rooftop 42 feet above the center of my street. This limits container size. I do not have access to pine bark fines so I use un dyed pine bark mulch. I add compost from my compost pile and pearlite at a 5-3-1 mixture. I am feeding with Jacks 25-5-15 till heavy blead through to drain into my vegetable garden. I have never lost a tree to root rot but I have lost a few and set back many to drought. My trees do most of their growing from September though February. I live and grow these in Cincinnati, Ohio zone 6 Just 8 hundred feet north of the 6a/6b growing zone

winter

6-15-23 now

Steve

Hey, Steve. I see what you mean. Unfortunately, Liebigs Law of the Minimum states that the cultural necessity least available is what limits a plant's rate of growth, the size to which it ultimately grows, and its overall health. It further states that increasing the supply of non-limiting factors will not increase plant growth rate, size, of vitality levels, and only by increasing availability of the most deficient factor will the plant performance improve. There is also an optimum combination of the factors and increasing them, individually or in various combinations, can lead to toxicity for the plant.

So, why do you grow citrus - for the fruit or the challenge?

Al

I get more fruit of my citrus trees than my apples, peaches ,grapes, blueberries, honey berries, cherries, figs, and goose berries. Before my New Zealand lemonade died I got 74 large lemons from it. I have gotten over 50 Fukushu kumquats and 30 Meiwa kumquats. The squrrels pike and discard all my non citrus fruit at half size. My NZL was growing big enough that I was hoping to get 100 or more lemons. After a years research I felt confident that citrus would be and excellent fruit to grow here.

So I have to laugh at myself. I spent hours looking for a complete fertilizer with with the elusive 3-1-2 NPK ratio in the EU and thought that I found something pretty good. Nevertheless, I was so exhausted, fed up, and uncertain that I went ahead and shelled out to import Foliage Pro and Pro-Tekt from the UK. And then Al tells me that I found a great Foliage Pro replacement in the EU. *Facepalm* But if my efforts end up helping some else, I'm glad! :)

I thought about that as I was sharing the info. As I noted, this question comes up a LOT, so I'm really glad to have the info, which I also posted on another forum site. It also prompted me to write a short piece about the attributes of Foliage-Pro 9-3-6, so I now have all that info saved as word documents I can cut/paste whenever. Thanks again.

Steve - wish I had some little nugget of knowledge that would help you deal with your concerns about low light, unfortunately ......

Al

@bluebelle_7a_germany

Thanks for the research and the useful information, I also spent hours looking for FP in europe or an alternative and was one click away from ordering it from the UK :D , but why I reconsidered it was actually the water analysis report which showed the tap water which showed 80mg ca and 20mg Mg, do you use tap water, in germany the chances are high that the water has enough calcium and Mg

@tapla (mid-Michigan, USDA z5b-6a)

Thanks for the wealth of useful info, I am learning a lot, I wish one day you can share all your posts in a FAQ style, the search function in the forum is very hard to make use of.

Regarding my citrus tree, it pushed a new cluster of flower buds, so good sign, but still no leaves

Earlier in the thread you mentioned that the crushed basalt i used to replace the granite could cause magnesium issues, I couldn’t figure out how much can end up being soluble in water, any ideas what to expect? And what would be the best way to balance it if needed ?

Also before starting this thread I was fertilizing with ~ 1/3 strength every time i water and I would flush every fourth time with water, are there pros/cons for the full dose i am using now or the diluted approach ? And when do use which approach

Many thanks

Fahmy

@Fahmy Lol I'm glad that I'm not the only one looking at hydroponics shops in the UK. :) I currently use tap water and am aware that it's hard (probably similar to your tap water). I would love to use distilled/filtered/rainwater/etc., but was going to address that issue down the road, once I have more time to see what is feasible. May I ask, how did you get your water analysis report?

Also, for some reason, I was operating under the assumption that my hard water wouldn't provide enough calcium and magnesium for plants, and so it is still important to use a fertilizer with those elements. But based on your comment and given our (probably similar) hard water, I'm now wondering if I don't actually need a fertilizer with calcium and magnesium (presumably it's not harmful to have though... ). @tapla (mid-Michigan, USDA z5b-6a), if you don't mind, how does water hardness bear on the necessity of using a fertilizer with calcium and magnesium? For the future, do I need/should I ideally use a fertilizer with calcium and magnesium if my water is similar to Fahmy's?

Thanks Tapla. I have a large tree that blocks light from 1 hour after TRUE noon for 2 hours. It is badly rotted and will come down. I suspect that my trees need more heat to induce flowering than I get. My new Zealand lemonade tree is happy with the lower temperatures and flowers profusely.

@bluebelle_7a_germany

May I ask, how did you get your water analysis report?

I live in Munich, the reports are published online, but as far as I know each provider is obliged to test their water, so easiest would be to email yours or give them a call, here are some of the published reports, check this link (water analysis Munich) for the reports of Munich (water from Mangfall), here is report for Berlin (they also have a tool to see the results by postal code) , and this one for Stuttgart (from Bodensee)

@tapla (mid-Michigan, USDA z5b-6a) Hi Al, I've potted up my citrus plant. The old soil is very hard, but I'm hoping that the new situation will be okay until next March/April when I will transplant the plant into gritty mix. Since repotting, the soil seems to be staying damp for a longer time (I previously went about 6-7 days between watering). The plant seems fine so far and its lemons are still visibly getting bigger.

As a thank you for your advice, I wanted to share a picture of my citrus plant:

Inside the larger pot, the plant is in a plastic pot that rests on a generous bed of stones. The plant sits on a long windowsill in front of a high (1.5-story) bank of SE-facing windows with a wide, unobstructed view of the sky. In the picture (though it might be hard to see), there are about 6 medium- to large-sized lemons visible (and not visible, about 8 marble- to medium-sized lemons on the other side). When I bought the plant at the end of March, it had two lemons on it and I've had two flushes of flowers since then. Truthfully, the shape of the plant needs work, but I can't really prune it without cutting off some lemons right now (although maybe that wouldn't be a bad thing to help the plant focus its energy). In any case, I have the impression that the plant is healthy and happy, which gives me a lot of satisfaction.

If you have a moment, I would still appreciate hearing your thoughts on how water hardness bears on the necessity of using a fertilizer with calcium and magnesium. Will plants take up the calcium and magnesium from hard water such that fertilizer with calcium and magnesium is optional?

Thanks again and have a good day!

It has been almost two month since the transplant

the plant had a signficant number of blooms, I counted more than twenty very fragrant flowers, came in clusters of 3-4, some of them developed small fruits before falling, was an unusual thing to see a tree covered with blooms but no leaves, and for the past two weeks it seemed like nothing is happening, i checked the mix without disturbing the roots and i found a lot of root growth, tiny white root tips looked healthy

I am watering every 3-4 days, it has been warm here (27c-30c) and the plant is facing a south-east window, sometimes i am fertilizing at full rate every 3rd time or half rate every other time, with silica added and ph dialed down using citric acid

Once i forgot to water and on the 5th day i noticed that the leaves wilted, I watered and in few hours the -few- leaves on the plant looked happy, this was a very good indication of quick water uptake by the roots

Yet the plant is not growing any leaves :( and after the blooms/fruits fell 2 weeks ago nothing visible has happened, today i noticed LOTS of tiny sprouts on the stem, but all of them are below the graft :(, I am so frustrated, i think i will remove all of that growth, but I don’t understand why the plant now has decided to focus the energy growing from the rootstock

All the tips on the plant top had flowers and some of them developed into fruits, so it is not dead

Any advices ?

on the other hand my hibiscus plants are exceptionally happy this summer

@Fahmy I noted your message, but we had company this weekend and I had little time to myself.

I checked the mix without disturbing the roots and i found a lot of root growth, tiny white root tips looked healthy. That's encouraging - a good sign.

Sometimes I am fertilizing at full rate every 3rd time or half rate every other time, with silica added and pH dialed down using citric acid. Dial back on the fertilizer until you see new top growth.Fertilizer doesn't provide energy, just the building blocks plants use to grow.If the plant isn't growing, it needs considerably less in the way of nutrition.How are you determining water pH and what is the actual pH of your water after has rested for 24 hours? Water fresh from the tap has a lot of dissolved CO2 which forms carbonic acid and lowers pH. Allowing the CO2 to gas off gives a much more accurate reading of pH levels.

Yet the plant is not growing any leaves :( and after the blooms/fruits fell 2 weeks ago nothing visible has happened, It's pretty much to be expected that when you do r ootwork, the plant halts top growth until it has a volume of healthy roots to support the additional top mass. today i noticed LOTS of tiny sprouts on the stem, but all of them are below the graft :(, I am so frustrated, i think i will remove all of that growth, Yes - no that. but I don’t understand why the plant now has decided to focus the energy growing from the rootstock. Perhaps a failed graft union?

Al