I believe Chlorosis is a deficiency in magnesium.

Dump a bag of greensand all around its drip line. As I mentioned elsewhere, it worked wonders for a tree I have in heavy clay soil that was chlorotic.

Second, heavily amending planting holes is usually not recommended. That could be contributing to your tree's decline. If you use the search function on this forum you'll see alot of thoughts on the good and bad of that.

I read something on a University website about taking 12-18 inch cores of soil from around the dripline and refilling them with a half sulfer/half chelated iron mixture. What do you think about that? Good idea or bad idea?

The chemistry of alkaline soil binds Iron and makes it inaccessible to plants, adding Iron to the soil would not fix it because the problem is not a lack of Iron, but a lack of the plant's ability to take in the Iron.

But... sulphur/half chelated iron is the best advice, as the sulphur will help acidify the soil at the same time. Great advice, I say go for it.

Then how come greensand worked great on this red maple that is growing right into caliche soil when I told my neighbor to try it? I'm not the only one that saw success with greensand which had pH of 8.0 when adding to alkaline soil....

I don't know what greensand is. We do not have it over here where I live. If enough of this amendment was added change the chemistry of the soil then that may be a part... I know from firsthand experience that simply adding iron does not help, not in the alkaline clay that makes up my part of the state, atleast.

Greensand is a source of potassium.

Yes, I've never heard of or seen greensand either. If any amendment or nutrient COULD make it to the roots, I think it would work. But I dump stuff on top of the soil (last year I dumped half a can of chelated iron on top) and my shallow-rooted flowers and shrubs all benefit, but my tree stays the same. I think the roots are too deep and the clay inbetween the surface and roots too dense.

HOW can I fix the dense clay issue around the tree without damaging the roots? I obviously can't till up the dirt where the roots are :(

Years ago, I had a rose friend in San Antonio. Every spring, her roses got quite chlorotic from a combination of high pH and a lot of rain. It happened to me once too, a couple of years later. It fixes itself when the soil dries out.

Unquestionably, this thing is living in a bathtub. How you fix that without digging it up, I don't know.

LOL. Greensand is 15-20% iron by weight! Ever heard of google??? All we did was throw on the top of the ground and it worked....

Greensand is a naturally occuring, mined, long-accepted and organic source of minerals: composition 1%P, 5-7%K; 50% silica, 18-23% iron oxide; 22 trace minerals. Its effects last for up to 10 years, applied at a rate of 10 lb. per 100 sq. ft. It loosens clay soils and is slowly available to the roots.

Mulching with a good organic mulch (in the sense of able to rot and break down, not as in certified) as widely as possible, no deeper than 4" and no mulch on the inch or 2 next to the trunk, will also help. Encouraging a goodly amount of earthworms (which usually means using little to no chemical fertilizers) will also help in breaking up and improving the soil - they help mix the mulch into the top of the soil as the mulch breaks down. I know that my clay soil is much improved from when I first dug holes and planted a trees or shrubs in it - mostly all I did was mulch since I started with a pasture and had no time to improve the soil with amendments except for flower beds and the vegetable garden areas.

lou, I don't doubt that it worked for you, but the thing about Chlorosis is that the alkaline soil does not LACK Iron, it binds the iron and makes it so plants cannot chemically extract it. That is soil science 101.

I did many searches on the subject but there was precious little information on the how and why it would work besides coming from companies selling the product or garden sources that don't explain how greensand 'works' to my satisfaction. I did a search for a real study with several phrases but no university studies or anything came up that would indisputably support it with hard evidence... This is not meant to be rudeness or anything, just me being cautious because I have heard many insta-fix home remedies that really have never been what they were cut out to be, see.

Fledgeling,

You're right about lack of studies and I had my doubts too but there were a couple guys that I have a lot of respect for and they did experiments to test it on their alkaline soil and they worked great. They too had doubt about it and they don't really know how it worked but it worked better than any other iron products like Ironite. Soil science 101? It has nothing to do with soil biology. You;re thinking in terms of chemistry. I'm thinking in terms of biology. Two very different things. We are a long way from figuring out what is going on in soil biology. Plant roots do produce a weak carbonic acid that would help extract nutrients and having mulch around plants help greatly as it promotes earthworm activities. They tend to make nutrients more available after they've passed through their guts. We have an advantage of having dirt cheap greensand in Texas to try out them out and most of us saw improvement from it . It doesn't appear to be the case in other states so I don't know if it's worth it.

Hey Fledgling and Tweedbunny, advice was asked for. Something from experience that worked in seemingly similar circumstances was suggested. For about 10 or 15 bucks you can try it or not. Do or don't your choice.

Will it work in other situations? Don't know. Is the same problem causing the decline in both situations? Don't know. Exactly what in greensand allows it to work where adding other forms of fertilizer and iron failed for me? Don't know.

But, don't suggest those offering results based advice don't know what they are talking about. I'll take experience 101 over soil theory, myself. It worked and continues to work for me every year. TB, if its a soil issue, odds are you won't be able to "fix" the clay issue. The greensand will get to the roots. Keeping it mulched and favorable to earthworms will help. Anything else really gets back to choosing a plant that is suited for the soil you are planting it in.

Give greensand a shot... or not.

Lou did say he used greensand on a Maple, notorious for being shallow rooted. Pears are not shallow rooted in my experience. So my thought would be that the maple got to the greensand nutrients faster, easier, because of the shallow roots. Showed improvement quickly. The greensand was quite expensive for a small quantity, when I checked it out.

I would be more likely to use the deep core method in clay,for getting some nutrients down to the root level of the Pear. I would also use Dibbets methods of mulching around the tree, don't let mulch touch the tree bark. Mulching is a very good way to have your earthworms come work for you. I like the shredded wood and my shredded leaves as a mulch food to feed worms, loosen up my soil. The wider the mulch ring, the better chance of tree getting some benefit.

Have you done a soil test? Recently?

Locally I need to add lime in my pastures of clay, to get the nitrogen loose from the soil, available to the grass roots. Without the lime addition, the nitrogen just sits there, plants can't get it.

This was explained to me by the fertilizer man, when I asked why I didn't need much of the other minerals in my pasture fertilizer like I had gotten before. He had the results from soil test number 2, which told us I needed to change products since the first soil test. I had improved things greatly, but now needed lime to "set the nitrogen free" for the plants to use.

I will be getting soil test number 3 on each of the fields, so we can check the progress of minerals in the soil. I need good grass for the horses, they do better on it. Grass is a cheaper feed than grain and hay.

Amazing what a soil test can tell you.

How often would Greensand have to be put out and how thick?
How long will the effect of it last? (1 yr, 2?)

Scotjute; as I said above - "Its effects last for up to 10 years, applied at a rate of 10 lb. per 100 sq. ft."

I would reapply it in about 9 years, if it were me, before the chlorotic effects showed up again.

Thanks to those who gave kind advice. Dibbit, I didn't know that greensand could actually loosen my clay soil - which I think is my main problem.

Since greensand is unavailable in my area (though I still may go with it later), I decided to go with the 'core method'. I bought a 2ft long piece of copper pipe, about 3/4 inch diameter and used a hammer to pound the pipe down into the soil, taking about 10 cores from around the tree. You should have seen the nasty soil that came out! It was red CLAY to the max, I could have fired vases with it! :)

I refilled the holes with granulated sulfer and Ironsafe and topped them off with soil. I realize it is going to be awhile before that sulfer and iron breaks down a bit and becomes avaialble to the roots. Since my tree needs help NOW (it has worsened from the pictures above and has brown edges and spots all over the leaves now), I also made a foliar leaf spray by dissolving some of the Ironsafe in water (0.3% solution recommended from university of utah website) and used a spray bottle to apply it after sundown.

I pulled the 3 inch deep mulch away from the trunk about six inches so the roots can breathe a bit (thanks for that advice, it made a lot of sense and I hadn't thought of it).

I did this all earlier today so no visible effects yet.
I'm thinking of taking 15-20 more cores and refilling with with compost to sort of deeply "aerate" the soil. I just don't want to damage the roots.

Well, in the name of full reporting, and I'm a little embarrassed to admit this, I put a forty pound bag around my pin oak every year.

Yes, its probably overkill. And, yes, I could probably back off of it and apply less now that I have brought it back, literally, from the brink of death, with greensand. Another pin oak literally died that was about forty feet away before I stumbled across the greensand "cure" (I had a bag left over one fall and just dumped it around the tree late in the fall in desperation and to get rid of the bag).

But, heck, it is working and the tree is a large nice one now that continues to thrive, so... why change what is working? Been doing it annually for about five years now.

It would probably cost a thousand bucks to replace the tree, so what is ten bucks a year?

I've got many other trees that don't need or get the special treatment. They get a little greensand in quantities along the lines of 10 pounds per thousand sq ft. But, the pin oak gets its dose of "mega vitamins" once a year. Its happy, I'm happy.

It sounds like green sand has some great nutrients in it that would greatly benefit your tree. But to fix your clay organic matter is what's needed, and not sand. Sand mixed into heavy clay does not loosen it, it makes it hard like concrete. I recommend copiuous amounts of mature compost, as much as you can afford, and as far from the trunk as you can. Worms WILL work this into the clay overtime. If you have no worms, buy some.

In the meantime, have your soil tested by a lab for pH levels. That will tell you immediately if you are having a plant problem or soil problem.

If your pH is too high, add sulphur. The coring and packing method is a very recommended one.

I have red worms in my soil, but how deep will they dig?! Not as deep as the roots of a tree will they?

rcnaylor,

I certainly never meant to suggest that the people who are offering their experiences dont know what they are talking about. I do not doubt the results and observations! I was trying to sound a cautious note because there is a large number of people in the local community, at least, who swear by salt as a herbicide. They use it and it works the point I was making was that while experience is important, knowing how and why it works is just as important, if not more so. For example, there was an elderly woman in a town I once lived in who grew the biggest and best tomatoes in the area, and how did she achieve such results? She claimed her ceramic garden gnomes were a part of her secret. Slat, gnomes my point is that experience in and of itself does not necessarily mean that it will work or that the process is not harmful.

However, there are many people not just here but, as I could see from the internet searches I did, elsewhere that have said that greensand has achieved remarkable results for them. That is a large number of people and their collective experience points that there is something significant about what is happening. Scientific studies simply prove beyond a doubt what was there all along. It is a confirmation more than a validation. Because there has apparently not been a study done does not mean that this does not work, will not work.
However, knowing how and why it works is absolutely vital, because it is through that knowledge that we can begin to know where, when, and under what conditions said process works in a reliable and consistent manner. Personal observation is valuable but it cannot tell us these things. So I am skeptical not because I believe the people who are offering their experiences with greensand donÂt know what they are talking about but simply because the available information on the process and results are not sufficient to completely dispel the potential that it is not the cure it is said to be. And I personally must know these things before I would recommend it to anyone as a remedy. So my skepticism is not dismissal, that is just how I personally operate with such subjects.

tweedbunny,

Your soil sounds horrible! If the clay is that dense then the planting hole could be collecting water. The problem could be excess water and poor aeration more than a chemistry problem. Do take greenhavens advice and get a soil test. It may be a larger issue than simple lack of iron.

Admittedly, your tree may be so unhealthy now that there is a potential that it might not survive but dont give hope because plants can stage remarkable recoveries. Ultimately the tree might turn out to simply not be adapted to your site. IF the tree dies, know that there are other kinds of trees that can survive on your land even if your pear cannot.

tweedbunny said:"I have red worms in my soil, but how deep will they dig?! Not as deep as the roots of a tree will they?"

I dunno...guess I'll have to look that up, but it really depends on how deep your roots go, and that is impossible to know. Redworms are good in your yard.

Have your soil tested, and add some compost to your soil until you get your results back.

In my personal opinion soil science, when it comes to understanding the vast interaction between soil, soil oranganisms, bacteria, and organic and chemical uptake of plants and companion plants is about where medical science was when doctors were applying leeches.

So, you can rely on that to supply all your answers before using "home" remedies that have been proven to work, many of them for thousands of years, or you can wait on science to advance with explanations that most soil scientists are not even looking to explain.

Personally I will go with trying an organic product like greensand that comes from the earth that has virtually no chance of doing any harm but might help over sitting around waiting for some soil scientist to get around to figuring out why it works scientifically.

Following your approach, I'd have two dead pin oaks instead of one dead one and one thriving one. At the rate we are funding science to research the interaction of the billions of interactions that can go on in soil/plant biology, they'll probably have a paper out on it some time next century.

But, to each their own.

And, having been there and done that a few times, after you've planted a tree if you want to do much for the soil around it and/or drainage and/or clay problem... keep it mulched with about 3 to 4 inches of hardwood mulch out to the drip line, try the greensand if you have chlorosis issues and water and fertilize enough but not too much. Big drainage or soil compatibility problems should have been factored in or fixed before planting (raised bed, drainage tile, wholesale soil changes, or simply a plant/tree adapted for the area and soil).

While the interactions of microbes in the soil biosphere are obscure, the chemistry and research regarding plant nutrition and nutrient deficiencies is solid and not in question. the agriculture and horticulture industry pours vast money into the field and the results are basically know. There is no ambiguity in this. There is no "theory" involved in plant nutrient needs. Are there things that are not known? Yes, but simply because scientists don't know everything about the subject is not grounds to dismiss everything they do know.

In regards to the pin oak, this greensand method is not the only way to acidify soil, there are other that could have been used. Personally I don't like to baby my trees with amendments to help them live in a soil chemistry that they are not adapted to. If they live they live - but i don't want to have to pour things on them every few years lest they expire. That just my personal opinion on the matter, though.

There is "no ambiguity in plant nutrition and nutrient "

Well, until they can explain the vast interworkings and symbiotic relationships of soil microbes, and various plants and nutrient types they haven't even studied, I would say your claim is extemely over broad and one no real soil scientist would try to make. You seem to be intent on tying your implied position, because soil science says iron gets bound up in alkaline soils it can't be remedied with organic amendments to a "scientific principle" which doesn't go that far.

You then attempt to use that overly broad claim of scientific unerpinning to determine that "acification" solved my problem. Really? How do you know that? It might have. You certainly can't know that as a scientific fact. Several other actions, or more likely combination of actions, probably contributed to the tree's vigor. 40 lbs of straight sulfer over the size of the area involved probably wouldn't have lowered the ph enough to overcome the bonding problem. The organic approach and trace minerals might supply, for instance, some microbial action that allows the binding effect to be lessened at the root level. Some microbes help plants generate nitrogen fixing at the root level, for instance. Microbes facilitate actions in the soil in ways large and small that we have little knowledge of or appreciation of at the moment. My personal guess is its less complicated. I just applied enough iron and trace nutrients to overcome the binding effect. The "get a bigger hammer" approach.

And, quite to the contrary of what you claim, I don't suggest that people "dismiss everything soil scientist know". In fact, I did a lot of review of the binding problem they point out about iron and alkaline soils and various possible remedies before I tried the greensand. The best scientific answer I found was to drill holes and place iron supplements in the tree trunk. But, the studies suggested it had to be maintained, was costly and rarely had good long term results. NO studies (generally funded by chemical companies) suggested greensand, despite its high iron content and trace minerals. And yet it worked. Likely, in my humble opinion, just because of the volume. (As mentioned above, the "get a bigger hammer approach" is one that I usually don't use in gardening, but keeps working here.)

As you can probably tell from my response one of my pet peeves is scientist who over state what they really know and can prove up scientifically. Like many on the global warming debate. We know something scientifically, the earth has been in a warming period of late, and then half baked psuedo science types insist we extrapolate from that scientific confirmation things like: therefore mankind did it, mankind has the ability to effect it, its definitely going to continue if we don't devote huge amounts of our economic resources to try to change it. Starting with one legit scientific observation doesn't give free reign to supply whatever next step one might be inclined to plug in UNTIL scientific trial and error has established it.

But, like with most debates, just because you over state your position about what science "knows" in this specific inquiry, and doesn't, doesn't mean you are entirely wrong.

I agree that its much better to not have to give supplements to a tree to keep it healthy. Whether by dry product, liquid or pellet form. If this wasn't already an otherwise nice tree in a location where I needed a nice shade tree, I probably wouldn't be bothering. But, since I inherited it and it takes about ten bucks and one act of "maintenance" a (or perhaps less if I experimented a little)to keep a tree that would cost a lot of money to replace with one of like size going strong, I think it well worth my time and money.