Two of my apple trees have this yellow/bronze look to the new growth. And another is all around very light green/yellow. Is this a simple nitrogen deficiency or something else?
The trees are in a yard and I fertilized with a 26-0-4 fertilizer in April. So I’m a bit surprised if it is an N deficiency.
Does anyone have thoughts on what deficiency this might be?
Wow thats a high nitrogen content! Most people wouldnt use something that high. I use a 5-10-10 granular. Im looking to attain some new growth along with developing flowering wood.
Could be micronutrients or phosphorus.
Did you do a soil sample, pH test?
The trees are in my lawn, so they do get a bit of N from the lawn fertilizer. I don’t aim for the trees, but they do get a bit of granules in the mulch rings.
Yes, generally I wouldn’t put much N on trees. At our previous house, I was managing vigor and not putting much N around my trees. In this new house I’m scraping the bottom of the barrel to get a few inches of leader growth.
I had a soil test last year, but I can’t find the analysis results. I recall soil pH is a bit high at 7.2 or so. I think potassium and zinc stood out as low. I think iron was fine, but that pH certainly is limiting on Fe. The problem was that the test was some new technology over your standard Mehlich 3 test, so the results were really hard to compare to your standard extension test…
In high pH soil the tree’s ability to uptake iron is diminished. Try to give them soluble iron in water acidified by vinegar.
Your fertilizer has no phosporus, so maybe a phosporus deficiency? I haven’t personally seen it in apples, but I know in some of my other plants a phosphorus deficiency can cause oddly colored foliage. Maybe use a more balanced fertilizer in the future?
Like Poppy says, I’ve recently been looking into phosphorus deficiency as I’m not getting good bloom on a number of things and apparently our area can be low. I’ve seen reference to deficiency in pear that seem to match.
Apparently higher than neutral PH can inhibit phosphorus take up by trees. So that acidifying/iron rec might help too.
I’ve bought a 50lb bag of bone meal to try.
I would suggest acidifying the whole area to bring it below 7. Then put on a nice balanced fertilizer to bring up the phosphorous and adding in some micro nutrients such as iron, boron, zinc, etc. I have a fertilizer company in my area, that usually carries a 5-10-10 fertilizer that i put down in spring and summer. Helps add in the phosphorus and potassium to help develop fruiting wood and it also helps to control vigor, while still making the plants grow some.
I doubt your soil ph is that much of an issue. Plenty of apples grow in similar ph (just ask Washington state). The leaves do not look chlorotic.
Its not that the pH is to high that is the issue, its that when the pH rises, it makes nutrients unavailable to the plant to be taken into the system.
Based on the chart, ideal pH would probably be between 6.5 and 7.0
Is that an apple chart or a general plant chart? Honestly apples aren’t that picky. 7.2 ph in Iowa should be plenty ok. That chart suggests that iron wouldn’t be that big of a deal…and those leaves don’t show an iron deficiency. Other nutrients, yes. It kind of depends on how heavily modified the soil is. Is it high clay due to home construction, or normal Iowa top soil? Does it drain?
Okay, so I found my soil test. Clearly it is lower on P than I thought. I have added K to the lawn with several fertilizer applications since Aug (one last fall and one this spring).
I took the sample from around 3 trees and mixed it. This “Soil Savvy” test is not a traditional test. I did not know that when I bought it. They advertise it as some sort of ion-exchange extraction method for short-term growing needs. It is not Mehlich 3 or Bray etc. So you can’t pull up an extension publication and compare.
pH is 6.85. Should be OK for iron, and I agree that the symptoms are not iron chlorosis-like.
The soil is glacial till modified from grading/home construction. Most people would call it clay but it really is probably more of a loam. (You can’t make a thumb ribbon with it very well.)
The developer did not do a bad job of adhering to the city ordinance and they put 6" of “black dirt” back in most places in our yard. It is a melange, really. I have spots where the sub-soil is gravel-and cobble-containing till and spots where you hit sand and dig sand for many feet.
I would not call what they put back “top soil” as it once was top soil that was removed and placed in piles for at least several years and put back on a few days before slapping sod on it. It drains OK. The back is low but I have M. fusca rootstocks there that are supposed to be able to take the wet. Incidentally, they seem to be very dwarfing here in my soil, and are probably the most affected by whatever nutrient deficiency there is. (Very little growth.)
Also of note: generally the rule here in Iowa is to never amend soil, but my trees that look the best and aren’t showing any deficiencies were in pots and planted with the potting soil left on the root ball. Those also had been fertilized with Osmocote 2 years ago.
After seeing the test, id be inclined to say that you are severly lacking in your micro nutrients, iron, boron and zinc. Id adjust those. Its amazing that adjusting a little thing or two can totally change a crop.
So the test results I have from last year generally were accurate enough. I sent out samples this week and got both leaf nutrient analysis and soil analysis back. I definitely have a significant soil pH problem as it is pretty high at 7.6. (I ran the same test at home and got 7.7 with my pencil pH probe I use for cider, so I buy that.) Also with the high soil pH there is also a clear deficiency of potassium, zinc, sulfur, and maybe manganese. 
The low Zn, S, Mn and S are reflected in the leaf analysis.
Mulch the tree with at least a 3’ diameter circle, better 5’ with shredded leaves and/or wood (or chips from an arborist) and you begin to create the forest soil parfait in which trees find what they need- sometimes from different layers. The interface between soil and mulch will represent a completely different nutritional harvest than the base soil.
Prairie plants tend to create a homogeneous soil while forest soils tend to be highly stratified. Ones good for herbaceous perennials and grasses the other for trees.
My theory, but I’ve seen anecdotes that support it hundreds of times- although prairie plants do thrive under most mulches as well.
And something you should know about grasses, they tend to produce chemicals poisonous to trees to control territory and assure access to sun. It is about more than just the competition for water and nutrients via root crowding. These chemicals stunt tree growth.
Alan - I might have to move that up on the to-do list. I do plan to put in a more defined area with a border and mulch around my orchard area in the yard. The leaf mulch is a good idea. A layer of leaves under wood chips would be easy to source locally in the fall. You are right that the best idea would be to treat the problem holistically - but I don’t know if I am patient enough for that…
I guess I’m really just a bit surprised that I have such a problem in this new yard compared to my last home. The strange thing to me is the free carbonate content of the soil. Generally the soils in this part of Iowa are leached of carbonate, even under historic prairie cover. I’m guessing most of the problem I have is due to the process of removing top soil to big piles and and replacing it during construction.
Since I am not doing anything different in the new yard, it was obviously a soil problem and I was trying to figure out what it was. The trees get the same sized mulch ring here as there and I treat it yearly with roundup (with a tree-tube collar around the trees) to kill the encroaching grass. I had way more vigor than I knew what to do with in my old orchard and climate is the same. Varieties are mostly the same, and while I have more Geneva rootstocks here, I do have several of the same combos and they are showing less vigor too. If I would have known I would have planted trees on M111…
You know what absolutely has no problem with this soil? Romance series cherries. My Juliet looks happy as can be.
Bush cherries are Prunus cerasus x Prunus fruticosa hybrids. Prunus fruticosa, which is also known as Mongolian cherry or steppe cherry, is native to the Eurasian steppe, which is similar to the North American prairie.
Texture can be more important than nutritional content. of course. Also OM works wonders. Usually when topsoil is replaced by contractors around here they replace it with something dreadful besides 2 or 3 inches of enough good soil to make it possible to grow grass. The most popular fill seems to be something called bank-run, which is course, full of gravel and very low on organic matter, but it’s still a lot better than the nearly pure subsoil clay one sometimes has to deal with.
I have one site where the contractor used pulverized concrete (pH in the 8’s!) covered by about 5" of bank run. I added about a half yard of compost per tree, mixing half of it with the “soil” and the other half as dressing under a quarter yard of shredded wood mulch, creating slight mounds. The trees have grown very well and are large enough now to bear good crops. They started as about 2.25" diameter “bearing age” trees from my nursery.
Incidentally, eliminating grass competition and providing mulch often gets about as quick results as fertilizer.
