Fertilizer Program for Containerized Plants III

11 years ago

This subject has proven popular on the Container Gardening Forum, having reached the maximum number of posts allowed on two previous occasions, so I'll post it for its third go-round. Nutrient supplementation has been discussed frequently, but usually in piecemeal fashion on this and forum and other forums related. Prompted originally by a question about fertilizers in another thread, I decided to collect a few thoughts & present a personal overview.

Fertilizer Program - Containerized Plants IIIsize>color>

Let me begin with a brief and hopefully not too technical explanation of how plants absorb water from the soil and how they obtain the nutrients/solutes that are dissolved in that water. Most of us remember from our biology classes that cells have membranes that are semi-permeable. That is, they allow some things to pass through the walls, like water and select elements in ionic form dissolved in the water, while excluding other materials like large organic molecules. Osmosis is a natural phenomenon that is nature's attempt at creating a balance (isotonicity) in the concentration of solutes in water inside and outside of cells. Water and ionic solutes will pass in and out of cell walls until an equilibrium is reached and the level of solutes in the water surrounding the cell is the same as the level of solutes in the cell.

This process begins when the finest roots absorb water molecule by molecule at the cellular level from colloidal surfaces and water vapor in soil gasses, along with the nutrient load dissolved in that water, and distribute water and nutrients throughout the plant. I want to keep this simple, so I'll just say that the best water absorption occurs when the level of solutes in soil water is lowest, and in the presence of good amounts of oxygen (this is where I get to plug a well-aerated and free-draining soil). Deionized (distilled) water contains no solutes, and is easiest for plants to absorb. Of course, since distilled water contains no nutrients, using it alone practically guarantees deficiencies of multiple nutrients as the plant is shorted the building materials (nutrients) it needs to manufacture food, keep its systems orderly, and keep its metabolism running smoothly.

We already learned that if the dissolved solutes in soil water are low, the plant may be well-hydrated, but starving; however, if they are too high, the plant may have a large store of nutrients in the soil but because of osmotic interference the plant may be unable to absorb the water and could die of thirst in a sea of plenty. When this condition occurs, and is severe enough (high concentrations of solutes in soil water), it causes fertilizer burn (plasmolysis), a condition seen when plasma is torn from cell walls as the water inside the cell exits to maintain solute equilibrium with the water surrounding the cell.

Our job, because we cannot depend on an adequate supply of nutrients being supplied by the organic component of a container soil as it breaks down, is to provide a solution of dissolved nutrients in a concentration high enough that the supply remains in the adequate to luxury range, yet still low enough that it remains easy for the plant to take up enough water to be well-hydrated and free of drought stress. Electrical conductivity (EC) of, and the level of TDS (total dissolved solids) in the soil solution is a reliable way to judge the adequacy of solute concentrations and the plant's ability to take up water. There are meters that measure these concentrations, and for most plants the ideal range of conductivity is from 1.5 - 3.5 mS, with some, like tomatoes, being as high as 4.5 mS. This is more technical than I wanted to be, but I added it in case someone wanted to search 'mS' or 'TDS' or 'EC'. Most of us, including me, will have to be satisfied with simply guessing at concentrations, but understanding how plants take up water and fertilizer, as well as the effects of solute concentrations in soil water is an important piece of the fertilizing puzzle.

Now, some disconcerting news - you have listened to all this talk about nutrient concentrations, but what do we supply, when, and how do we supply them? We have to decide what nutrients are appropriate to add to our supplementation program, but how? Most of us are just hobby growers and cannot do tissue analysis to determine what is lacking. We CAN be observant tough, and learn the symptoms of various nutrient deficiencies - and we CAN make some surprising generalizations.

What if I said that the nutritional needs of all plants is basically the same and that one fertilizer could suit almost all the plants we grow in containers - that by increasing/decreasing the dosage as we water, we could even manipulate plants to bloom and fruit more abundantly? It�s really quite logical, so please let me explain.

Tissue analysis of plants will nearly always show NPK %s to be very close to an average ratio of approximately 10:1.5:7. If we assign N the constant of 100, P and K will range from 13-19 and 45-70 respectively. (I'll try to remember to make a chart showing the relative ratios of all the other essential nutrients plants normally take from the soil at the end of what I write.) All we need to do is supply nutrients in approximately the same ratio as plants use them, and at concentrations sufficient to keep them in the adequate to luxury range at all times.

Remember that we can maximize water uptake by keeping the concentrations of solutes low, so a continual supply of a weak solution is best. Nutrients don't often just suddenly appear in large quantities in nature, so the low and continual dose method most closely mimics the nutritional supply Mother Nature offers. If you decide to adopt a "fertilize every time you water" approach, most liquid fertilizers can be applied at 3/4 to 1 tsp per gallon for best results. If you decide that is too much work, try halving the dose recommended & cutting the interval in half. You can work out the math for granular soluble fertilizers and apply at a similar rate.

The system is rather self regulating if fertilizer is applied in low concentrations each time you water, even with houseplants in winter. As the plant's growth slows, so does its need for both water and nutrients. Larger plants and plants that are growing robustly will need more water and nutrients, so linking nutrient supply to the water supply is a win/win situation all around.

Another advantage to supplying a continual low concentration of fertilizer is, it eliminates the tendency of plants to show symptoms of nutrient deficiencies after they have received high doses of fertilizer and then been allowed to return to a more favorable level of soil solute concentrations. Even at perfectly acceptable concentrations of nutrients in the soil, plants previously exposed to high concentrations of nutrients readily display deficiency symptoms, even at normal nutrient loads.

You will still need to guard against watering in sips, and that habit's accompanying tendency to ensure solute (salt) accumulation in soils. Remember that as salts accumulate, both water and nutrient uptake is made more difficult and finally impaired or made impossible in severe cases. Your soils should always allow you to water so that at least 10-15% of the total volume of water applied passes through the soil and out the drain hole to be discarded. This flushes the soil and carries accumulating solutes out the drain hole.

I use a liquid fertilizer with a full compliment of nutrients and micronutrients in a 3:1:2 ratio. Note that 'RATIO' is different than NPK %s. Also note how closely the 3:1:2 ratio fits the average ratio of NPK content in plant tissues, noted above (10:1.5:7). If the P looks a little high at 4, consider that in container soils, P begins to be more tightly held as pH goes from 6.5 to below 6.0, which is on the high side of most container soil's pH, so the manufacturer probably gave this some careful consideration. Also, P and K percentages shown on fertilizer packages are not the actual amount of P or K in the blend. The percentage of P on the package is the percentage of P2O5 (phosphorous pentoxide) and you need to multiply the percentage shown by .43 to get the actual amount of P in the fertilizer. Similarly, the K level percentage shown is actually the level of K2O ( potassium oxide) and must be multiplied by .83 to arrive at the actual amount of K supplied.

To answer the inevitable questions about specialty fertilizers and "special" plant nutritional requirements, let me repeat that plants need nutrients in roughly the same ratio. 'RATIO' is also an entirely a separate consideration from dosage. You�ll need to adjust the dosage to fit the plant and perhaps strike a happy medium in containers that have a diversity of material.

If nutrient availability is unbalanced - if plants are getting more than they need of certain nutrients, but less than they need of others, the nutrient they need the most will be the one that limits growth. There are 6 factors that affect plant growth, vitality and yield; they are: air, water, light, temperature, soil or media and nutrients. Liebig's Law of Limiting Factors states the most deficient factor limits plant growth, and increasing the supply of non-limiting factors will not increase plant growth. Only by increasing most deficient nutrient will the plant growth increase. There is also an optimum combination/ratio of nutrients, and increasing them, individually or in various combinations can lead to toxicities and be as limiting as deficiencies.

When individual nutrients are available in excess, it not only unnecessarily contributes to the total volume of solutes in the soil solution, which makes it more difficult for the plant to absorb water and nutrients, it can also create an antagonistic deficiency of other nutrients as toxicity levels block a plant's ability to take them up. E.g., too much Fe (iron) can cause a Mn (manganese) deficiency, with the converse also true, Too much Ca (calcium) can cause a Mg (magnesium) deficiency. Too much P (phosphorous) can cause an insoluble precipitate with Fe and make Fe unavailable. It also interferes with the uptake of several other micro-nutrients. You can see why it is advantageous to supply nutrients in as close to the same ratio in which plants use them and at levels not so high that they interfere with water uptake. I know I'm repeating myself here, but this is an important point.

What about the high-P "Bloom Booster" fertilizers you might ask? To induce more prolific flowering, a reduced N supply will have more and better effect than the high P bloom formulas. When N is reduced, it slows vegetative growth without reducing photosynthesis. Since vegetative growth is limited by a lack of N, and the photosynthetic machinery continues to turn out food, it leaves an expendable surplus for the plant to spend on flowers and fruit. Plants use about 6 times more N than P, so fertilizers that supply more P than N are wasteful and more likely to inhibit blooms (remember that too much P inhibits uptake of Fe and many micro-nutrients - it raises pH unnecessarily as well, which could also be problematic). Popular "bloom-booster" fertilizers like 10-52-10 actually supply about 32x more P than your plant could ever use (in relationship to how much N it uses) and has the potential to wreak all kinds of havoc with your plants.

In a recent conversation with the CEO of Dyna-Gro, he confirmed my long held belief that circumstances would have to be very highly unusual for it to be ever beneficial to use a fertilizer in containers that supplies as much or more P than either N or K. This means that even commonly found 1:1:1 ratios like 20-20-20 or 14-14-14 supply more P than is necessary for best results.

The fact that different species of plants grow in different types of soil where they are naturally found, does not mean that one needs more of a certain nutrient than the other. It just means that the plants have developed strategies to adapt to certain conditions, like excesses and deficiencies of particular nutrients.

Plants that "love" acid soils, e.g., have simply developed strategies to cope with those soils. Their calcium needs are still the same as any other plant and no different from the nutrient requirements of plants that thrive in alkaline soils. The problem for acid-loving plants is that they are unable to adequately limit their calcium uptake, and will absorb too much of it when available, resulting in cellular pH-values that are too high. Some acid-loving plants also have difficulties absorbing Fe, Mn, Cu, or Zn, which is more tightly held in alkaline soils, another reason why they thrive in low pH (acid) soils.

So, If you select a fertilizer that is close in ratio to the concentration of major elements in plant tissues, you are going to be in good shape. Whether the fertilizer is furnished in chemical or organic form matters not a whit to the plant. Ions are ions, but there is one major consideration. Chemical fertilizers are available for immediate uptake while organic fertilizers must be acted on by passing through the gut of micro-organisms to break them down into usable elemental form. Since microorganism populations are affected by cultural conditions like moisture/air levels in the soil, soil pH, fertility levels, temperature, etc., they tend to follow a boom/bust cycle that has an impact on the reliability and timing of delivery of nutrients supplied in organic form, in container culture. Nutrients locked in hydrocarbon chains cannot be relied upon to be available when the plant needs them. This is a particular issue with the immobile nutrients that must be present in the nutrient stream at all times for the plant to grow normally.

What is my approach? I have been very happy with Foliage-Pro 9-3-6 liquid fertilizer. It has all the essential elements in a favorable ratio, and even includes Ca and Mg, which is unusual in soluble fertilizers. Miracle-Gro granular all-purpose fertilizer in 24-8-16 or liquid 12-4-8 are both close seconds and completely soluble, though they do lack Ca and Mg, which you can supply by incorporating lime or by including gypsum and Epsom salts in your fertilizer supplementation program. Ask if you need clarification on this point.

I often incorporate a granular micro-nutrient supplement in my soils when I make them (Micromax) or use a soluble micro-nutrient blend (STEM). I would encourage you to make sure your plants are getting all the micro-nutrients. More readily available than the supplements I use is Earth Juice's 'Microblast'.

When plants are growing robustly, I try to fertilize my plants weakly (pun intended) with a half recommended dose of the concentrate at half the suggested intervals. When plants are growing slowly, I fertilize more often with very weak doses. It is important to realize your soil must drain freely and you must water so a fair amount of water drains from your container each time you water to fertilize this way. Last year, my display containers performed better than they ever have in years past & they were still all looking amazingly attractive at the beginning of Oct when I finally decided to dismantle them because of imminent cold weather. I attribute results primarily to a good soil and a healthy nutrient supplementation program.

What would I recommend to someone who asked what to use as an all-purpose fertilizer for nearly all their container plantings? If you can find it, a 3:1:2 ratio soluble liquid fertilizer (24-8-16, 12-4-8, 9-3-6 are all 3:1:2 ratio fertilizers) that contains all the minor elements would great.

How plants use nutrients - the chart I promised:

I gave Nitrogen, because it is the largest nutrient component, the value of 100. Other nutrients are listed as a weight percentage of N.

N 100

P 13-19 (16) 1/6

K 45-80 (62) 3/5

S 6-9 (8) 1/12

Mg 5-15 (10) 1/10

Ca 5-15 (10) 1/10

Fe 0.7

Mn 0.4

B(oron) 0.2

Zn 0.06

Cu 0.03

Cl 0.03

M(olybden) 0.003

To read the chart: P - plants use 13-19 parts of P or an average of about 16 parts for every 100 parts of N, or 6 times more N than P. Plants use about 45-80 parts of K or an average of about 62 parts for every 100 parts of N, or about 3/5 as much K as N, and so on.

If you're still with me - thanks for reading. It makes me feel like the effort was worth it. ;o) Let me know what you think - please.

AL

Here is a link to the second posting of A Fertilizer Program for Containers

Another link to information about Container Soils- Water Movement and Retention.

Featured Answer

tapla (mid-Michigan, USDA z5b-6a)
Original Author

11 years ago

last modified: 8 years ago

Grizz - The average P use for every 100 parts of N would be about 17 parts of N (100:17). 1:1:1 fertilizers like 20-20-20 still supply more P than plants will use as a function of N usage. P is reported as the amount of P2O5, so to determine how much P is in a 1:1:1 ratio fertilizer, we need to adjust the 1 part of reported P by a factor of .43, so 1:1:1 ratio fertilizers actually supply NPK at a ratio of 1:.43:.83. Since plants (on average) only need about .17 parts of P for every 1 part of N, 1:1:1 ratio fertilizers can easily be considered high P fertilizers because on average they supply 2.5x more P than the plant will use.

Once the photosynthesizing machinery is in place, reducing the N supplied to 50:15(P), or 100:30(P) would be a good starting point. It is also common in greenhouse applications to start the crop with 3:1:2 ratios and then change to a 2:1:2 ratio to curtail vegetative growth but still allow bloom formation. This is part of the reason you see small, stocky, yet sexually mature plants blooming in tiny cell packs. Switching to a nitrate source of N (I think FP 9-3-3 supplies 60% of its N in nitrate form) also helps keep plants compact and from stretching out.

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Comments (150)

Bob1016
11 years ago
last modified: 8 years ago
Al, please understand that I did not mean to offend you, or to seem arrogant. These were not my intentions, in fact I respect your opinion very much because I have not seen many people use a fast draining coarse mix for regular containers, and the independent genises of the idea proves that it is a logical conclusion (although they may be different, the intentions are the same; as you said). I asked your opinion because I value your advise.
And I accidentally assumed, which I'm sure you know what that means (an ASS of U and ME), that you did not repot often due to my lack of knowing your bonsai background.
jdwhitaker
11 years ago
last modified: 8 years ago
"...occasionally I purposely use the stress of tight roots to achieve a particular end."

What would that end purpose be, Al? I'm guessing that the stress increases blooms.
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"It looks like you switched to the Dyna grow 9-3-6 last year. Do you still use CRF in your soil mix if you are still using this fert?" Actually, I rarely use the CRFs at all. I like the near complete control the soluble fertilizers give me in containers. I'm pretty diligent about fertilizer applications, so I really don't need the CRFs to cover the 'in case I forget' base, or for any minor elements they might supply. I included them in the soil recipes to make it easier for others. As long as you're faithful to your nutrient supplementation program, you can easily do w.o them. If you think you'll be lax at times, I'd include them. 109 ppm alkalinity is nothing to be overly concerned about with fast container soils. It would be interesting to learn how the Ca and Mg levels are though. Alkalinity is related to pH because alkalinity (practically speaking and for our applications) determines your water's resistance to pH changes. If you have water 'A' at a pH of 9.0 with an alkalinity of 75 mg/L CaCO3, and water 'B', with a pH of 8.0 (a full point lower to begin with) and alkalinity of 300 mg/L CaCO3, it will take about 4 times as much 35% H2SO4 (sulfuric acid) to bring the water with the lower pH down to That aside - your water is better than mine, so I really doubt you'll have Fe/Mn issues if you're using either the 9-3-6 or MG. I will say though, that bark/peat soils have a potentially high Fe:Mn ratio, so applying Fe w/o Mn could easily create a deficiency of Mn. If I were in your shoes, I would do nothing until I actually saw evidence of an Fe deficiency. Then, I would acidify. Oh - the other likely cause of an Fe deficiency is too much P, which combines with the Fe to form an insoluble precipitate, so avoid the high P fertilizers - they are useless unless you are using them to supply the exact amount of P needed while intentionally (severely) limiting N. I used this strategy last year: I fertilized with regular dosages of 9-3-6 until the plants were well established. I then cut way back on the dosage and added ProTeKt to the solution. I rather like to envision that I used the added K (and got the benefit of the added silicon) to change the fertilizer ratio to 3:1:3 from a 3:1:2. This allowed me to reduce the dosage of N (reducing vegetative growth) while still having adequate P and K. Take care. Al
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Hi, Al. I see this is an old post, but I'm hoping you get to see this comment because, well, I'm in NZ, and some things (like liquid fertilisers) just aren't as cheap here as they are in the States, and I'm wanting to come up with a cheap way to feed my containers (and mostly because I am endowed with the blood of Scotsmen.....extra-cheap Scotsmen at that!). :) Soooooooo, here are my thoughts. In NZ, we have grass.....like, LOTS of grass....enough grass to feed about 30 million hungry sheep! My lawn has got to be more useful than just to provide my weekly exercise cutting the darn thing. I was browsing around the net and found an interesting article on grass tea as fertiliser. To cut a long article short, the science behind this 'tea' said the NKP turned out to be about 1-.5-3.1. I'm no maths professor (so correct me if I'm wrong), but I figured the ratio of this to be 2:1:6.2. Right? Anyway, I know this is a little off your recommended ratio of 3:1:, so I'm just wondering if I can add a little (cheap) something to improve the ratio, or is this a pipe dream? I can get the STEM quite cheaply (because it goes a long way). So, what do you think? If you have the time to indulge me, I'd appreciate your advice. Thanks. :) Michaela
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TheMasterGardener1
11 years ago
last modified: 8 years ago
"...occasionally I purposely use the stress of tight roots to achieve a particular end."

Yes. I was thinking of the same thing today!!!

When a plant gets root bound it starts to bloom more.

So if you plant right you will end up with the right size plant full of fruits/blooms.

This is what I think it meant anyway.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
Bob - I'm not easily offended or moved to ire unless I think someone's agenda includes intentional personal effrontery. You've been polite & given no indication of anything other than honest intentions, so I'm fine with our exchange - no bad or sour note as you hoped against on another thread you recently initiated. All's well.

JD - Tight roots can to some degree be a bonsai practitioner's friend, if they are managed judiciously. Other growers can employ the strategy for the same reason a bonsai artist might. Tight roots slow growth; cause reduced branch extension, which means shorter internodes; and reduce leaf size. Because tight roots also affect vitality and have a tendency to cause the shedding of foliage proximal to meristematic regions (branch tips), you can easily end up with a weak plant and the poodle look resultant from tufts of foliage only near branch ends.

If I want to maximize growth and o/a vitality, I'll grow in a large soil volume & repot every other year. I actually make an educated guess about how much soil volume I'll need to keep the roots from getting compacted to the degree that I can lift the root/soil mass from the pot intact. An excellent guideline is, once that state of root congestion is reached, the plant will be negatively affected in growth (as measured by the increase in o/a mass) and vitality, permanently, unless the root congestion in the original root ball is corrected.

A plant can regain lost vitality, but it can never regain lost growth potential, something particularly important when growth:time is a consideration.

..... and yes, tight roots can induce a more prolific bloom period in many plants. It's important to recognize though, that the result of the stress of tight roots pleases the grower, and not the plant. Stress always carries danger with it because it indicates an organism operating under energy drain or life processes operating at/near the limits for which they were programmed. Unchecked, stress always leads to strain, which is a permanently injurious condition that can lead to death of the organism.

Al
Bob1016
11 years ago
last modified: 8 years ago
Thank you for understanding Al, it is not the first (and unoftunately, probably not the last) time my tone has come across as offensive.
I am interested in getting your opinion on the other topic i started (I didn't want to overrun your fertilizer thread with a soil question). Thanks for the help.
Also is the art of bonsai hard to get started in? I have always wanted to try but never got around to it.
TheMasterGardener1
11 years ago
last modified: 8 years ago
Was doing a study on specific acids on plants and they are NOT amino acids. Can I confirm one more time that there really is no reason for them or they dont do anything?

Thanks.
TheMasterGardener1
11 years ago
last modified: 8 years ago
Just looked up the ingredients of dyna-gro and found it has Indole-3-Butyric Acid. It seems it enhances the growth of plants. It says it's uses "Growth enhancer to increase both yield and quality."

Not sure which one it was.
Bob1016
11 years ago
last modified: 8 years ago
MG - IBA (indole-3-butyric acid) is a plant hormone in the auxin family, it is very commonly found in rooting powders and the like. Auxins are produced in the buds on a plant, and are responsible for many of the plants activities: fruit development, branching and elongating roots, elongation of other cells, and quite a few others that I can't remember. If you choose enlist this powerful force, be careful, because an imbalance of phytochemicals can cause many irreversable growth defects. If a fertilizer you have includes any of these it is probably ok to use, just be aware that they are there. If you want be more adventurous and try your hand at dosing out these chems yourself, know that you should keep constant balance between auxins, cytokinins, and gibberellins. It can yeild amazing results if you dose them yourself (and it's a great learning experience), but I honestly don't think it is worth the trouble for my small gardening, if I had a greenhouse the that would be a different story.
Sorry to ramble, just thought it might be useful info if you have never heard some of these terms, Bob
TheMasterGardener1
11 years ago
last modified: 8 years ago
"Sorry to ramble, just thought it might be useful info if you have never heard some of these terms, Bob"

Ramble? Yea right, you have a lot of very good information. Thanks.

Yea that must of been their rooting compound.
Bob1016
11 years ago
last modified: 8 years ago
Just out of curiousity, are you a certified MG, I always wondered if it was worth it?
capoman
11 years ago
last modified: 8 years ago
On the note about tight roots, I have another example as well. I have several young plum trees in my yard. One of them got accidentally girdled by a whipper. The next year, it flowered and fruited like crazy, but not a lot of vegetative growth. Meanwhile, the plum trees that did not get girdled doubled in size, but had fewer flowers and no fruit. I would assume the girdling would be an equivalent to tight roots in a pot.
TheMasterGardener1
11 years ago
last modified: 8 years ago
I looked high and low for foliage pro but my local retailer only has grow 7-9-5. I know the p level is way high but it says it is a good fertilizer to use all the time on all plants. What do you think about grow?
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
You answered your own question.

In a conversation with Dave Neal, the CEO of Dyna-Gro, he mentioned that virtually everyone using 7-9-5 SHOULD be using 9-3-6.

Al
TheMasterGardener1
11 years ago
last modified: 8 years ago
Well in that case, I will try to get them to order it. So glad you take the time to teach this, I would not know these things. Thanks Al. : )
octoberust
11 years ago
last modified: 8 years ago
I am catching up as quickly as possible, but the amount of information provided here is amazing! I may have found the issue to my problem is the need for gypsum, but am not sure. I have become a "Taplite" if you will and have been transferring my plants to the Gritty Mix as well as using Foliage Pro 9-3-6. I am growing several tropical bonsai under a 400w metal halide lamp and have begun running into problems. My Schefflera loves it and can't seem to get enough, but two ficus microcarpa have been showing signs of what I believed to be iron deficiency. The new growth slowly turns yellow and falls of while the old growth remains and appears healthy. All of these plants are in my old soil mix which does include more fines, so is more water retentive. Also, all of the plants showed signs of general fertilizer deficiency and became a pale green. I doubled the fertilizer dose, as recommended on the package, and the plants greened back up. Only the ficus are having problems at this point, but are slowly dropping 3-5 new growth leaves a week. If gypsum is the answer, where can I find it? Thank you in advance for any advice, and in the mean time I will also be trying to digest all of the information on these forum threads!
octoberust
11 years ago
last modified: 8 years ago
Okay maybe no gypsum. I almost forgot to mention my very hard tap water has a pH of 8.5 or higher. Way to high! The double dose of foliage pro, recommended for deficiencies, lowers the pH to 6.o. Sorry for the additional post, but I thought the information might be helpful.
TheMasterGardener1
11 years ago
last modified: 8 years ago
Would I be better off just staying with MG all purpose fertilizer rather then dyna gro grow 7-9-5, considering it is like a 3;1;2 ratio? And added gypsum. I have MG tomatoe fertilizer on hand too.

Thanks.
octoberust
11 years ago
last modified: 8 years ago
A photos of the leaf progression from bottom to top; old growth, new growth beginning to yellow, new growth very yellow just before falling from tree, and a dead leaf after falling and drying.
{{gwi:27796}}

Here is a link that might be useful: Bonsaisite forum thread
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
So you're fertilizing with 9-3-6 at double the recommended dose & your tree is dying ..... or at least leaves are abscising (being shed)?

Al
octoberust
11 years ago
last modified: 8 years ago
Yes, but only on my ficus microcarpa. The rest of the plants under the light are doing great. Well my ficus benjamina does show yellowing in the new leaves but then it fades back to green. My brazilian rain tree has stopped growing but is not loosing leaves, and the schefflera has been thriving.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
Ok - how about describing how you're fertilizing - a double dose how often? My first thought right off the bat, if I understand you correctly, is that you're dealing with a very high level of EC/TDS, which is essentially the level of dissolved solids & salt) in the soil, leaving your plant unable to take up water properly, dying of thirst in a sea of plenty.

How recently was the plant moved under the lights, and what was the light level like where they were formerly sited?

Al
octoberust
11 years ago
last modified: 8 years ago
I am thinking you are on the money with the dying of thirst in a sea of plenty. I water once or twice a week if needed and have been using the double dose for about a 3 weeks every time I water. The plants were moved under the light about three months ago and really became pale and washed out with the normal fertilizer dose about three weeks ago. The light they were moved from is a southern exposure with direct light four to five hours a day and a very high level of reflected light all day. I was not exactly clear before that it is two ficus microcarpa dealing with these issues. Thanks for the replies and let me know what other information I can give you.
octoberust
11 years ago
last modified: 8 years ago
Today was watering day, and before I did anything I took some time to research the signs of over fertilizing. Thick leathery leaves with a bluish tinge on older growth, as well as yellowing and abscessing leaves on new growth. Both signs were apparent on my plants. Even if I am misreading the signs I felt giving my plants a good flush couldn't do any harm. I watered with luke warm tap water and made sure to really flood and drain the soil multiple times. I then let the plants to sit for fifteen minutes and watered again with distilled water. My thinking is that the luke warm water would help to loosen up the mineral deposits during the fifteen minute delay between watering and ending with distilled water would help to flush everything possible out. There is still a very week dose of pelleted Bougain fertilizer on the soil surface, but it is very week and most likely predominately micro nutrients at this point.

I believe my my metal halide growing expectations have been unrealistic. I felt with the abundance of new light my fertilizer program had to go through the roof. I am starting over with a much more diluted fertilizer program. I will start with my pre lamp winter fertilizer program, which was half recommended strength twice a month. Thanks again for all of the help and please correct me if any of this is incorrect.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
I think your plan is well-considered and very realistic, and pretty much coincides with what I might have done. Great job on the research too, btw.

Take care.

Al
weirdflowers
11 years ago
last modified: 8 years ago
Any recommendations on how to add Ca during fertilization, rather than mixing gypsum or lime into the potting medium beforehand?
Bob1016
11 years ago
last modified: 8 years ago
Hard water usually has a decent amount of Ca. I take my old egg shells and dissolve them In lemon juice or vinegar, just be carefully of the amounts you use: you want to make sure you nurtralize the acetic acid, either use a pH test, or simply keep adding eggshells until they stop dissolving. This is very strong, so you really don't need much at all, plus if you use cider vinegar you will give the plants a lot of extra trace minerals and some other useful compounds (vitamins and such).
I use this method because it gets rid of garbage and makes almost free fertilizer. You could also use pickling lime or many other common substances, but calcium acetate and calcium citrate are some of the most soluble forms of calcium.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
WF - First, let's visit why you think you need an extra measure of Ca, or why you don't wish to use dolomite as a Ca/Mg source.

Al
weirdflowers
11 years ago
last modified: 8 years ago
Curiosity I guess. When you add dolomite, what form is it in?
DaMonkey007
11 years ago
last modified: 8 years ago
It's generally prilled or in a fine powder form. It is the cheapest and easiest step in the process, there is absolutley no reason to skip it.

I use the prilled form, by Espoma. I have noticed that, at least with this brand, it is best to let the lime react for a few days, or even a week or more. Watering too soon after mixing, for me anyways, has resulted in grey runoff laden with lime. I also use landscape fabric at the bottom of my pots, and the lime runoff does not play nice with this product, it seems to clog up the pores. I tested this a number of times in a number of pots by immediately watering a fresh mix with no lime, and the runoff drained freely and was clear every time. I'm not sure how much you actually lose, but it's enough to make me simply mix it a week or two before I actually use it.

PJ
TheMasterGardener1
11 years ago
last modified: 8 years ago
"Hard water usually has a decent amount of Ca. I take my old egg shells and dissolve them In lemon juice or vinegar, just be carefully of the amounts you use: you want to make sure you nurtralize the acetic acid, either use a pH test, or simply keep adding eggshells until they stop dissolving. This is very strong, so you really don't need much at all, plus if you use cider vinegar you will give the plants a lot of extra trace minerals and some other useful compounds (vitamins and such).
I use this method because it gets rid of garbage and makes almost free fertilizer. You could also use pickling lime or many other common substances, but calcium acetate and calcium citrate are some of the most soluble forms of calcium."

Wow!!!!
katorahble
11 years ago
last modified: 8 years ago
I have a question concerning the weak fertilizing method with Foliage Pro. I apologize if this has already been answered. I read through most of the forum, but just wanted to clarify. I noticed most of the users speak about using the gritty mix with this method. I'm a beginner gardener so I was looking to pick up a potting mix from a local nursery. I've read that most commercials don't aerate and drain well so I figured I would have better luck from someone local where I could discuss the recipe and get a better idea of texture. Would I still have success with this method if using a sphagnum peat moss recipe? I'm growing a variety of vegetables in large containers and I like the idea of a basic fertilizer that I can use for all of them. I've already worked out companion plants, spacing, and successive planting plan so right now it's really a matter of proper water and fertilizing.

Also, can someone point me in the direction (or link) of where I might find more information about using a wick for gauging moisture? I've read about testing the soil using your finger up to your knuckle but not the wick and would like to learn more about it.

Thanks!
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
Your plant's preference would be that you fertilize in such a way that insures that all the essential nutrients plant normally take from the soil are present and available for uptake at all times, in the ratio at which the plant uses the nutrients, and at a concentration high enough to ensure no deficiencies yet low enough to ensure the plant has no difficulty taking up water and by default, the nutrients dissolved in that water (a high level of fertility makes it more difficult for the plant to absorb water).

It's easiest to achieve that through regular applications of a soluble fertilizer that closely matches the plants uptake ratio and with a dosage in a range that keeps the level of fertility in the favorable range. In order to use this strategy, your soil must be open enough that you can flush it to rid it of accumulating salts when you water.

How successful you might be depends on whether you can get accumulating salts out of the soil w/o impeding root function. There are ways you can do that with wicks and techniques that are variations of pot-in-pot or pot-in-trench, so you're on the right track in that regard if you intend to use a heavier soil. There is really nothing wrong with a program that's based on 1-2-3-4 .... week intervals between applications if you're diligent. I think the 'low dose/frequent application' method is better, but other methods sure won't bring the sky crashing down around your shoulders. ;-)

When using water retentive soils, a wick used correctly is very helpful for removing excess water. When the planting matures so you need a longer interval between waterings, simply pull the wick out. To determine when water retentive soils need to be watered when a wick is in place, feel the wick where it exits the soil. If damp - withhold water unless you're sure the plant will be (drought) stressed before your next opportunity to water.

You can also use a long wood skewer stuck deep into the soil as a 'tell'. If it comes out damp/dirty/cool on your cheek or inside of wrist, don't water. If it comes out clean/dry - water.

Best to you!

Al
paul61nakz4
11 years ago
last modified: 8 years ago
AL.

I will be receiving 1 yr old blueberry cuttings in a couple of weeks,I will be using the 5-1-1 mix which has a 4.4ph. on some of them I will use the foliage pro and to make up for the lack of ammo nitrogen I would like to use urea as ammo sulphate would lower the ph. My question is how much urea would I mix with the foliage pro if I watered every week?
I really appreciate all you do AL. You are a God sent for your knowledge, and your willingness to educate us.
Thank you very much
fortyonenorth
11 years ago
last modified: 8 years ago
Paul - FP wouldn't be my first choice for fertilizing blueberries. As you've suggested, most of it's nitrogen is in the nitrate form. Why not choose another, more appropriate, fertilizer?
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
..... like MG 24-8-16 or 30-10-10 ..... or other fertilizers that derive their N from urea.

Al
TheMasterGardener1
11 years ago
last modified: 8 years ago
Yes I am agreeing with Al. If your medium for your blueberry plants are adjusted to the right ph the fertilizer is only to give nutrition.
bronxfigs: New York City/7b
11 years ago
last modified: 8 years ago
There was a time in the recent past, when I would spend my too-scarce money on gardening books. No more. Now the "book-money" gets converted to "plant-buying money"...and I just read all of Al's postings on how to grow plants, and why certain things work...all backed up by science, and scholarship.

I stripped all my gardening products to the barest minimum, and I am much better off with fewer mediums/fertilizers/supplements/ macro-micro tonics that WORK!

Thanks, Al for the Botany Class on the Forum. We are all in your debt...and we're better growers because of your shared knowledge, and postings.

Thanks a million.

BronxFigs/Frank DV
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
MG - That's not something I would say because I understand the impact fertilizers have on media pH and how difficult it is for the hobby grower to adjust to, or maintain pH at a particular level. Neither would I say fertilizers are used to provide nutrition because it's so obvious, or that they are ONLY used as a nutritional source w/o qualifying that statement. It's always nice to have someone agree with you, but please make sure you're agreeing with something I said, to avoid putting words in my mouth. Also, my request doesn't require an explanation or a lengthy back and forth exchange, so I would appreciate having this as the last word on the matter - please?

Thank you.

Al
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
Thank you, Frank. That was a wonderful compliment & I sincerely appreciate it. No need to feel indebted. I get a lot of satisfaction from helping where I can; so much so I guess I probably feel like I get much more than I give. In that light, I suppose you could say it's sort of in the light of selfishness that I post. At any rate, I enjoy nurturing plants, so why not add nurturing people who nurture plants as a way to broaden the scope of my interest?

Thanks again.

Al
greenman28 NorCal 7b/8a
11 years ago
last modified: 8 years ago
Good morning, Al!

I just purchased my first bottle of Pro-TeKt, and I want to make sure I'm using it correctly.
The label says add Pro-Tekt to water first, then my fertilizer. Anyhow, that's what I'm about
to do, and thought this might be helpful to others.

Also, got a fairly decent price on the Pro-TeKt ($13) and another bottle of Foliage Pro 9-3-6 ($17).
The Hydro store owner is making me a happy return customer :-)

Josh
TheMasterGardener1
11 years ago
last modified: 8 years ago
Al,

"That's not something I would say because I understand the impact fertilizers have on media pH and how difficult it is for the hobby grower to adjust to"

That says it all right there. Ok thanks. I enjoyed reading about the fertilizer program.
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
Josh - if you add the Pro-TeKt to undiluted fertilizer, one or more of the nutrients precipitate and you end up with material that won't go back into solution when you dilute it. It doesn't matter which you add (to the water) first, only that you don't mix the two together before you add to water. Sort of like it's ok to add really concentrated acids to water, but adding water to concentrated acids is sure to make you blink when it erupts.

Al
greenman28 NorCal 7b/8a
11 years ago
last modified: 8 years ago
Hehe...thanks, Al ;-)

Josh
Loveplants2 8b Virginia Beach, Virginia
11 years ago
last modified: 8 years ago
Hey Josh,

I have been been using Pro-Tekt with my Foliage Pro all winter and i can say that my plants have definately been happier than in the past...

When i take my rain water and place it in my watering cans, i add the Pro Tekt first to all of the water and then stir it in. (1/4 tsp per gallon) Then i go back and add my Foliage Pro to the water. I keep it upstairs and let it warm to room temperature and then water.

The combination of the two will definately help your plants and im so happy to have found my Pro Tekt. My Hydroponics dealer had to order it for me. I still can't find or he wont (says he cant..) order it for me. He looked it up and says its not available. Hmm? I still order my Foliage Pro from Ebay. They have free shipping anyway.

Have fun with your Pro Tekt!!!

Hope you are feeling better!!!

Happy Spring AL!!!

Take Care,

Laura
greenman28 NorCal 7b/8a
11 years ago
last modified: 8 years ago
Thanks, Laura!

I am much recovered, and I think that only allergies are plaguing me now ;-)

I gave all my citrus, my avocado, and my potted Hungarian wax pepper the Pro-TeKt treatment
on Saturday, and now I'll see how they all react. It will take some time before I can tell, of course.

I'll start my Hoyas soon, too, since they seem to attract pests more than my other plants.

Are you adding Pro-TeKt with every watering?

Josh
Loveplants2 8b Virginia Beach, Virginia
11 years ago
last modified: 8 years ago
Hi Josh!!!

I do add Pro-Tekt at every watering (1/4 tsp) as well as (1/4 tsp) of Foliage Pro during the winter. Once summer arrives and my trees/plants are placed outside, i will raise to 1/2 tsp of Foliage Pro. I use this on all of my trees, C & S , Citrus etc.

Today i placed about 60+ Plumeria outside. We are expected to have temps all week in the mid 70's and the lows in the mid 50's. So... i decided to pull them out to enjoy the temps. Since i did this... We will have a blizzard next week! : ) They are all doing well and i have about 6-7 inflos already!

Hope your Allergies calm down..i also have the same problem. Definitely isnt fun. So glad to hear that you are feeling better tho!

My Hydro dealer can order the Pro-Tekt, but for some reason he cant order the Foliage Pro.. HUH?

Take care,

Laura
maple_grove_gw
11 years ago
last modified: 8 years ago
Hello,

I am thinking about adding silicon (i.e., Pro-TeKt) to my fertilizer regimen and have a question: will it benefit all container plants, or just deciduous plants? Don't know why it crossed my mind that there might be a difference, but I was wondering whether or not it would be beneficial to conifers in particular.

Alex
tapla (mid-Michigan, USDA z5b-6a)
Original Author
11 years ago
last modified: 8 years ago
I've noticed a difference in my plants since I started using the Pro-TeKt several years ago. I have less issues with insects & fungal infections, and my plants seem to tolerate heat much better. I have at least 100 conifers in containers, and they seem to benefit as much as the other plants.

Al
tapla (mid-Michigan, USDA z5b-6a)
Original Author
10 years ago
last modified: 8 years ago
I had to look up this thread so I could post a link to it, when I did, I noted it was about to top out at the maximum number of posts allowed. In order that I might link to the new thread, I'll take the liberty of using up the last couple of posts so there is an easy to find link at the end. See you at the new thread (see next post).

Al
tapla (mid-Michigan, USDA z5b-6a)
Original Author
10 years ago
last modified: 8 years ago
Hopefully, this will close out the thread & provide an easy link to the new one.

Thanks for your participation and the good fellowship!

Al

Here is a link that might be useful: Fertilizing Containerized Plants IV

Fertilizer Program for Containerized Plants III

tapla (mid-Michigan, USDA z5b-6a)Original Author

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