Iron Treatments for Chlorosis
An Iron deficiency in trees and shrubs can be spotted by the tell-tale yellow leaves. A further clue is that the leaf veins will be darker green than the rest of the leaf. Some trees become Iron deficient because the soil is depleted, others have problems picking up Iron out of the ground.
Treating an Iron deficiency in trees is often said to be difficult or impossible but I can tell you this is not the case. I have successfully and permanently corrected hundreds of trees in Northern Colorado.
Not all of them are easy: pin oak and Autumn Blaze can be particularly tough to treat. Most other plants are fairly easy.
We often see Iron deficiency in roses, pear trees, crabapple, grape vine, birch, aspen and serviceberry. These plants can be turned around usually in a couple weeks, but some may take up to a year or so.
As I said, pin oak and Autumn Blaze maple are harder to treat. About 6 out of 10 that I treat look better after the first treatment, which is actually pretty good results. Those 6 that do respond will just need continued Iron treatments once to twice per year and evetually they’ll be close to 100%. Sometimes all it takes is one treatment for a near complete turn-around.
The other 4 out of 10 trees, the ones that don’t respond, I can tell you: more soil-applied Iron will not help so don’t waste your money (Note: this only applies if ArboRx is doing the application. Most companies have no luck with Iron treatments even on the easy trees). These stubborn trees have one last shot at redemption, described below.
I start with soil-applied Chelated Iron. Basically I mix up a tank full of water and powdered Iron and pump it in the ground around the plant. It takes a lot of Iron, and I use from 8 to 100 times as much as my competitors to get the results I get. It’s not complicated but if you don’t give the plant enough, nothing happens.
If that treatment option fails, which usually only happens with some Autumn Blaze maples and pin oak, we go to Plan B. This involves a “macro” trunk injection of Iron solution and two secret ingredients. A macro injection is different from the micro injection most companies do in that instead of injecting a few ounces (or worse, stuffing capusles in the trunk) we are injecting a few gallons. The treatment is so powerful it blows the leaves off the tree, so we do it in October only. The next spring, the tree should leaf out nice and green and stay that way for two years and then another treatment is needed.
Iron Treatment Timing
Timing an Iron treatment is important. The first year, treatment is done as soon as possible, but in subsequent years I prefer to apply the Chelated Iron in the fall. This is because tree roots do most of their growing in the fall, picking up trace elements (such as Iron) for use in next year’s foliage as they go. Roots continue to expand pretty much right up until the ground starts to freeze. Applying the Iron in late September to early October puts the full amount of Iron at root’s reach when they are most able to absorb it. Trunk injections are done only in October.
Soil applied Iron treatments are about $110 to $160 for the first tree for most small to medium trees. The “Plan B” Iron treatment is considerably more expensive.
Complete recovery for this hawthorn in just a few weeks!
This Birch tree was looking like maybe it just needed to be removed, but less than a month after its treatment it was well on the way to recovery.
This rose bush was so low in Iron the leaves were almost white. A few months later it was looking much better.
Another dramatic single season change after just one treatment.
Complete turn-around in serviceberry in just a couple months. I consider this typical results for serviceberry.
A Pin oak five weeks after treatment starting to get some color and push out some new growth.