Deep root fertilizing?

My question is this, is there an ideal time to deep root fertilize trees? I use Arbor Green and would like to get it done soon so the fertilizer is well distributed into the soil by spring.

The main problem here is no rain and rock hard ground, there is no way I can push the injector into the ground. Will it be ok to let the fertilizing go a few weeks until it rains and the ground softens?

Ray

Personally, I think deep-root fertilizing is over-rated and over-used. It seems to me the "arborist" benefits($$$) more than the trees. But to answer your question, I think application of fertilizers should be done in the late dormant season just before spring growth. Applying nitrogen fertilizers now may encourage a late flush of new growth which will be susceptible to cold damage. And on sandy soils, most of the fertilizer can leach out before its used. In a perfect world, fertilizers would only be applied as needed after a soil or plant tissue analysis.

If leaves are falling and the ground is not frozen (does that happen in NC? I remember it getting chilly for only a few weeks of the year.) then fall application of nitrogen fertilizer will help stimulate new root growth.

Though I come from the camp that believes that using a NPK fert without other benificial elements is not good for a tree. The theories that brought us these practices come from annual crop agronomics.

I wont say that companies that do it are only looking at their bottom line, they may just not keep up with current research. Or maybe they don't believe it.

Why is it called "Deep Root" fertilizing?

It is squerted into the soil about six to eight inchs down as aposed to soil drench or dry spreader.

Fetilizing trees is a tremendous money maker for my company and we have the results from saving thousands of trees to back our work up for. Some of the posters here think that fertilizing is a waste of time well there nuts and they have obviously made no money in this great avenue of tree care to make money. There are thousands of tree companies throughout the country that fertilize trees and shrubs on clients properties and they make tons of money at it. I have one simple saying when it comes to the tree industry --- you can only cut a tree down one time but you can prune it, fertilize it, cable it many many times over and make money every time doing the application to a tree. To say that fertilizing is a waste of time is ridicolous in my book.

Thanks for the replies! I do not question the effectiveness of deep root fertilizing, I know it works! I have several customers who wish to have it done I just can't get into the ground right now without drilling. Here is a photo of how well it works, both of these trees were the same size and planted the same time, can you guess which was deep root fertilized?

Originally posted by KevinM
Some of the posters here think that fertilizing is a waste of time well there nuts and they have obviously made no money in this great avenue of tree care to make money.

Click to expand...

Au contrare, mon frere, I made a lot of money fertilizing trees also. I do not dispute the fact that it is tremendously profitable. However, my conscience and published research have led me away from fertilizing. In the past 3 or 4 years, I have only done a handful of fertilizing jobs, mostly for chlorotic oaks or manganese deficient palms. You think I'm nuts for refusing to rip off my customers? Maybe I am. Your post makes it sound like all we should care about is making as much money as possible. I have nothing against making money, I just think as professionals our first concern should be for our clients, the trees. By the way, current research is showing a correlation between excessive fertilizing and increased insect pest activity.

To KirbysLawn,
Congratulations. Now that you've forced that tree to grow up into the wires, are you going to top it, too! (Oh, sorry, am I being rude?)

...or is the tree just growing faster because it has already been pruned (hacked) for line clearance. The trunk diameter and leaf color look about the same.

If 90% of the absorbing root hairs are located in the top 6-8 inches then why inject it below?

We'll actually Eric...the fertilized tree has a 9" larger trunk, one is 22" the other is 31" . I don't want to start a debate, just looking for an answer to the above question.

Originally posted by KirbysLawn
1-My question is this, is there an ideal time to deep root fertilize trees?


2-The main problem here is no rain and rock hard ground, there is no way I can push the injector into the ground.


3-Will it be ok to let the fertilizing go a few weeks until it rains and the ground softens?
Ray

Click to expand...

1-According to Shigo the ideal time is when the tree has put out the initial flush of growth and is beginning to store nutrients. New Tree Biology and Modern Arboriculture are great sources for more infomation.

2-If your customers want it then have them put the sprinkler out around the trees. If it is so dry then the trees need water more than they need fert. There will also be more root burn when the soil is so dry. You can also use the technique of "greasing the probe" which is when a small amount of fert is released while pushing the probe into the ground. In the many years doing ferts up and down the east coast I never had a problem with actually getting the material into the ground. I had many questions as to wether it was good for the trees/shrubs.

3-Yes, Roots are active through out the winter, just not as much. I have fertilized well into Dec. when I worked for other companies.

I'm not looking for debates either. I do think that we should know and understand (as much as possible) what we are actually doing and wether it is actually benifiting the the plant. Yes, fert does produce results, the subject of much current research is wether it is of benifit to the tree. See some of Ed Gilman's stuff. It's time to think outside the box.

Due to lack of time I won't even go into the "deep root" issue but think about where the majority of the absorbing root hairs and mycorrhizae are located.

Thanks for the great reply. I'm sure there are differing views on this as with most any subject. Around here we deal with clay/rock soil which hold hardly any nutrents or water. Soil testing here usually shows low pH levels and CEC's that are close to nothing. My opinion (as dumb as it may be) any nutrents provided to the trees is much better that what is in the soil now. I have tried the "greasing the probe" method, it works sometimes, most of the time it does not.

Again, thanks for the great info.

Any is better then nothing....

Hmmm.

I love discourse! I want it!

Then go "organic". Use fish (Peeyueeww) or seaweed emulsions.

I see the big problem as being that we gige this big dose of N that boosts growth but there are no other other of the needed elements availible in the quantites needed to produce phytotxins.

Shoot length and leaf size may increase but studies show that photosynthesis does not!

The seaweed stuff I was useing at MCC cost me .75-1.00 per gallon.

Now for the question, why do we realy. I worked for one of the biggest fert squerting companies around, I know the profits that can be made. I've also seen the pest problems increase with using science based on agronomics developed from annual crops.

For some interesting reading on fert see what the A-300 Fertilization standard says. That might get you out side of the box.

I don't know about paying a dollar a gallon for dead fish... I always figured fertilizing was about nitrogen, period.
If a soil test reveals some other deficiency, then that can be supplimented, but to randomly add micro nutriants seems silly and expensive to me.
I would look at what nursery producers are up to, after all, they know how to make the trees grow.
Find a cheap source of nitrogen, apply it at a modest rate, and apply it often.
On phytotoxins, sure there may be a few more insects attracted to the tree, what self respecting bug wants to chew on a sickly tree that smells like dead fish? And with all those beatiful, lush, green leaves, on that huge, healthy tree, who cares if a few get chewed?
Tell me that photosynthesis isn't greater on a large tree than a small one...sheez.

Mike, I agree with your Nitrogen bit. Makes logical sense to me. Fish seems........fishy. If the fish is not totally broke down, it will take nitrogen from the soil in order to break it down, then later it will help in the fertilization. The idea stinks to me Just an honest joke JPM. I have heard of it, just not sold on it.

Buy a bottle of Alaskan Deoderized Fish Emultion and apply it to a chlorotic oak (be perpared to heave your last meal. I'ld hate to smell the stuff with an oder!) Heck the Amerinds taught the white invaders to plant crops with dead fish.

We talk about plant health. If the treatment makes the tree less resistant to pests (I&D) then how are we contributing to health?

If we want to make a growth spurt, why dont we make sure that the other elements are availible?

I can see a short term program to getab a tree started, but many companies fert trees year after year after year. With just NPK, or maybe N alone.

Shigo talks about paying the taxes, the sead parts of a tree fall to the ground an the constituant elements get used again. But we in our persute of "neatness" rake the laeves and pick up twigs. This on land where the topsoil has been robbed. Mike I know a lot of new developments around you have vertualy no organic topsoil. So where are the trees going to find avalible parts of Mr Hopkins CaFe? The grass clippings?

John, if I get up and jog around the block a few times I'll be in better shape, but with your philosophy, I'm better of staying home so I don't get hit by a truck.

My guess is the Amerinds used dead fish "leftovers" because they had it, and rather than throw it away, put it to use, to add organic matter to the soil. I doubt they would spend the day fishing and then throw the whole fish away.

What the hell is my point? Amerinds had extra fish guts, we have cow droppings. Compare the price per pound of cow manure to fish emulsion, then tell me which product would improve the soil structure and fertility better, for your dollar.

Now, on chlorotic oaks, you and I live in southeastern Wisconsin, which sits on a limestone bedrock and we have typically HIGH soil pH. Every homeowner thinks their oak is chlorotic because of it, but you and I know it's because of what they did to the root zone, change grade, trench, rototill, add septic, compact, ect.

I visit a site with chlorotic oaks (typically white oak, pin oaks do fine here and they are the one's that like acid soils) and see root damage. I can make them green by drilling the trunk and injecting iron, dumping nitrogen, or squirting fish guts on them(your method of choice), but the underlying problem is root damage.

What might be better for the tree is to reduce stresses and slowly improve soil structure. One could do a soil test to see if there are deficancies and correct those, water during times of drought, control pests, aerate soil, modestly apply organic matter in the root area, carefully remove plants that compete with the tree(buckthorne, grass, hostas, ect.), and for the trees sake don't remove ANY live branches, yes, even suckers and even lower branches.

My point is that if we are going to add something that will increase the mass of the plant dramaticly, we should have the other elements needed for growth redily availible also.

I whole heartedly agree that there are other regimines that can be done to improve tree health. (pneumatic soil fracturing, introduction of soil macro organisms..).

Like I said above, we remove the organs that acumulate the elements as they are shed. The soil is lowly deleated. Cow manure wont have the same concentration or wide spectrum of elements that guts will, these things accumulate in the organs. Another reson why I tought the emultions is that they are availible OTC RTU. No need to age or anything. you can tank mix and soil inject. As for this seaweed stuff that Danny Quast sells it has a high analysis of cytokinin which is a root hormone.

I once went to a seminar on fertilization by Dr Ed Gilman. He said something to the effect of just use N unless soil test or preferrable tissue analysis shows deficiencyof another element. He said that his studies show that N does more for root, flower, resistance,etc than P and K were thought to.

The A-300 fertilization standards talk about soil tests before doing any fert and appling only what is needed.

Perscription fertilization!

Now that sounds like a Professional arborist. I wonder what high end clients will pay for that verses one tank for all plants at 1#N/1000 sq ft.