Compost Tea for fertilizing trees

[az10sgal]

I had an arborist come to my house to give me an estimate for deep root fertilizing the many trees on my property. He said he uses compost tea instead of chemical fertilizers. I am familiar with compost tea for use in gardens and for lawn care, but am uncertain if this is an effective fertilization method for trees. I'd like to hear some opinions from other professional arborists before I make a decision. Thank you!

 

[Urban Forester]

I have no problem using compost tea for trees. I also have no problem w/synthetic fertilizer. It really depends on what the tree needs. It would be reasonable to me to start w/a soil test to determine what the soil already contains, or doesn't. Tea is very effective at reducing pathogenic soil fungi. This has been proving many times in vineyards. The NPK count, while organic in nature is low, compared to synthetic and has no slow release element. If your trees are lacking in one of the "macro" (NPK) nutrients than synthetic may be the way to go. A soil test will determine what is or isn't needed.

 

[Ekka]

I am familiar with compost tea for use in gardens and for lawn care, but am uncertain if this is an effective fertilization method for trees. I'd like to hear some opinions from other professional arborists before I make a decision. Thank you!

Answer this question for me.

In a forest, or rain forest, are the trees fertilized ever?

Synthetic or chemical fertilizers ARE NOT the answer, but building a comprehensive soil food web is.

I liken trees being fertilized to people on life support. Wouldn't you rather a self supportive environment?

Deep root fertilizing, spears go down and inject a solution, lots of evidence suggesting it's very beneficial to the applicators bank balance rather than the soil profile and tree roots.

You can make your own tea easily, but better still .... why not simply mix a concoction of readily available ingredients and water in. Mix up some seaweed product, soluble silicon, mycorrhizal fungi, liquid blood and bone and a dash of soil wetting agent all in a watering can with rainwater and water in. Might have to mix a few watering cans up that's all.

Mulch (natural in forests) is also a key component, lawn around trees not so good, so see if you can get a better environment for your trees.

Not all mulches are good either, avoid the 100% bark one (pine bark mostly) and the fine ones, best ones are coarse mulches preferably aged from wood chippers of tree guys, they contain a blend of leaves, wood and bark.

There's some good info here about fertilizers, soils, and fungi.

 

[Bermie]

Why deep root fertilizing when most of the feeder roots are in the top 18"...hmmm.

And...is there anything wrong with your tree now? Are they showing symptoms of any problem? Yes, no?
If they are, has the problem been correctly identified so the solution is tailored to that problem?

'Fertilizing' seems to be a one size fits all 'treatment'...when large established trees are generally just fine on their own.

Improving the root environment is the best start if there is a problem, relieve compaction and add good quality organic matter.

 

[Ekka]

Inserting a spear only compacts it more, a core decompacts ... if soil is not removed from the existing mass (like a core) then all you are doing when entering the spear is compacting it at the edges of the hole ... the facts have been out a long time about this inaccurate process. Surface applications have been shown to be most effective. Add core holes and mulch and you have an unbeatable combination.

You would be better off drilling holes with an auger and removing the soil swarf, adding matter down the hole but beware of adding material that can decompose turning anaerobic, there are processes that replace the core with polystyrene balls, coarse sand and an extremely good one called zeolite etc.

 

[treeseer]

I had an arborist come to my house to give me an estimate for deep root fertilizing the many trees on my property. He said he uses compost tea instead of chemical fertilizers. I am familiar with compost tea for use in gardens and for lawn care, but am uncertain if this is an effective fertilization method for trees. I'd like to hear some opinions from other professional arborists before I make a decision. Thank you!

Since we do not know about your soils or the proposed work ("deep root" might mean 6") it would be crazy to criticize it, or to diy. Your arborist likely has a better handle on what to apply and how. Ask for, and follow up on, local references; they are your best source of info.

My experience is like TreeCo's--aeration and blending is very beneficial.

 

[Ekka]

aeration and blending is very beneficial.

That is old school, new school has debunked this old tale and provided better alternatives.

 

[treeseer]

I am familiar with compost tea for use in gardens and for lawn care, but am uncertain if this is an effective fertilization method for trees.

It can be very effective, depending on the application. If you have clay subsoil, as much of southern AZ has, aeration helps a lot. Using a wand and delivering liquid under pressure helps break up the clay. So does a punch bar or a pick, with little root disturbance. Augering (drilling) cuts a lot more roots, and glazes the sides of the holes, like clay on a potter's wheel. This was commonly done in the last millennium; not now.

The ISA distributes peer-reviewed science from university researchers from around the world. Here's a start:

http://auf.isa-arbor.com/request.asp?JournalID=1&ArticleID=29&volume=28&issue=2&Type=1

This study shows that organic amendments even without aeration is beneficial:

http://auf.isa-arbor.com/request.asp?JournalID=1&ArticleID=2987&volume=33&issue=2&Type=1

As Urban Forester said, inoculating with good microbes can decrease the bad microbes that cause disease.

If your arborist is familiar with the ISA Best Management Practices on fertilization, that's a good indicator of competence. Let us know how other trees cared for by this arborist are doing.

 

[Boa07]

I had an arborist come to my house to give me an estimate for deep root fertilizing the many trees on my property. He said he uses compost tea instead of chemical fertilizers. I am familiar with compost tea for use in gardens and for lawn care, but am uncertain if this is an effective fertilization method for trees. I'd like to hear some opinions from other professional arborists before I make a decision. Thank you!

If someone is charging you for a fertilization program then ensure that you are happy with the methods they have used to determine what they propose to add to your soil, and what they claim these amendments are going to do for your plants.

It should not be too difficult to determine if the Arborist really has a grasp of soil and plant biology, of the physical and chemical properties of your soil. There are these days a very large range of tests that can be conducted to support or refute opinions about your specific soil problems...not all of those basic tests require a lab in a major teaching University to complete either!

I am always very willing to give the kind of general advice others have written here, and like them (I assume) do so without charge. General soil amendments like seaweed extract, fish emulsion, black strap molasses and organic silicon should by now be common knowledge amongst Horticulturalists and Arborists.

Individually tailored PHC is something that requires more detailed investigation and testing (the results of which the client should be provided with) and the application of both the experience, knowledge and understanding of the professional and as such should be paid for.

 

[Ekka]

If you have clay subsoil, as much of southern AZ has, aeration helps a lot. Using a wand and delivering liquid under pressure helps break up the clay.

Incorrect. :monkey:

One of the key things to note about compacted soils is that inserting a solid tube or tine increases compaction. Whilst you have a hole you actually have not heaved or removed soil so "squashed" soil adjacent to the hole you made.

Hollow tubes or tines like a corer on golf courses removes soil, you have the same volume but less mass now. ripping does the same, it increases the volume of soil.

So if you insert a probe into the soil, hit it with compressed air and there's no heave or increase in volume has the density changed? Nope.

In effect to decompact the soil you need to decrease it's density or mass for the volume..... if 1m3 of uncompacted soil weighed 1500kg and then you drove over it wet with a 10 ton truck 100 times and re-weighed it taking 1m3 of soil you'd find now you'd have perhaps 1800kg of weight. In effect the particles have been rearranged and pores made smaller or removed.

Now to decompact it the volume has to increase.

What some studies have shown is that roots exploit tiny cracks and fissures, they take the path of least resistance. I have spoken previously about literally getting an auger drill bit and drilling the ground creating holes, which removes soil. Then getting a steel rod or something and roughing up the edges of the hole. That will create fissures for roots to go down, it will allow air and water down along with organic matter. We cant rip around tree roots but we can drill verticle holes removing mass and allowing microbes to work deeper.

These holes do not have to be large diameter or very deep. I would say 1' deep would be plenty and 3/8 dia plenty. To prevent root damage you can root map and stay outside of the SRZ, mind you ramming crow bars and leveraging the soil damages roots.

Read Tree roots in the built environment
By John Roberts, Nick Jackson, Mark Smith

 

[Ekka]

If you are washing material up and out of the hole then you are correct, many do not, they inject with no washout. You have a good system then. Maybe you'd like to expand on the system you use with some demo or pics.

The reasoning behind my statement was provided, soil to be removed otherwise no reduction of mass, logical. Some just have a spear go down and blast liquids or air, not much use in clay, although in sandy soils it does help, but compacting sandy soils is also difficult to do.

The only negative I see in your method is using lots of water and making the site wet, and working on wet clay is not the best. with drilling you'd do that dry.

I'm sure a drill could be made that when it's in it's desired length then stopped from rotating and pulled straight up and it it scores the hole ... be the go, then put that on a multi-head plate and do like 1m2 at a time on a Kanga attachment.... I have been thinking about this for a while.

 

[Urban Forester]

I have always been under the assumption (obviously wrong) that forest trees are constantly being "fertilized" by the process of biogeochemistry. The introduction of the elements essential for life. The "introduction" of these elements is VERY different than in an urban forest where a sustainable source of these elements is not readily available due to the loss of organic matter and the natural decay process. It amazes me that an Arborist would not make use of ALL the tools that are available to him/her. Everything has its place, some more than others, but to dismiss fertlization to is limit your options.

 

[az10sgal]

Thank you for all your excellent feedback. You have given me some important information and now I know what kind of questions to ask.

This is the second time in 12 months that I have had a company come out to give me an estimate for treating my trees. Most of my trees actually look good, but I have 2 "orchid" trees (I don't kinow the correct name for them, but that's the common name in the Phoenix, AZ area) that look sickly. The edges of the leaves are brown and the interior of the leaves are a yellow/light green color instead of deep green. After the first estimate, I did not go ahead with any fertilization because the estimator, who was a certified arborist, just took one look at the trees on my property and then prescribed deep root fertlization. I was left with a feeling that this company was more interested in collecting money from me than actually diagnosing and creating a specific treatment plan for my trees. It was as if I went to a doctor who prescribed the same medication for all his/her patients no matter what the symptions were.

I talked to two more companies on the phone and had the feeling they operated the same way. Then I had this second company come last week and that arborist said he prescribes compost tea because salts build up in our arizona soil and that heavy treatments of synthetic/chemical fertilizers can add to that problem.

I've given you this lengthy discussion because I would like to know how to find an arborist who actually analyzes the soil and decides on the treatment accordingly. Our yellow pages are full of tree companies with certified arborists, but they all seem to operate the way I described above. How do I find an arborist like those who have responded to my post?

Thank you so much for your help!

 

[Ekka]

I have always been under the assumption (obviously wrong) that forest trees are constantly being "fertilized" by the process of biogeochemistry. The introduction of the elements essential for life. The "introduction" of these elements is VERY different than in an urban forest where a sustainable source of these elements is not readily available due to the loss of organic matter and the natural decay process. It amazes me that an Arborist would not make use of ALL the tools that are available to him/her. Everything has its place, some more than others, but to dismiss fertlization to is limit your options.

Who dismissed it?

Are forests fertilized or soil conditioned?

I say fertilizer in the context of a chemical compound that is ready for take up by the tree (not organic) usually manufactured.

As az10sgal has shown, deep root fertilizer prescription for what could be existing root damage, excess soil salts or pH out of range. The thing about organics is it's hard to do damage and over do it.

One method builds a long term sustainable soil profile the other can build an imbalanced hostile environment and a life support system for the tree.

Options considered which is the better way to go? And to steer the client toward a self sustainable environment less susceptible to pathogens is preferential than one that becomes a life support system and hostile.

TreeCo, your device sounds great, like to see it in action, is it a shelf item or home made?

 

[Urban Forester]

Are forests fertilized or soil conditioned?

As I said in my original post, Yes, forests are continually "fertilized" and/or "conditioned" by the process of biogeochemistry. The "elements" they receive come from a different source, but none the less it is "elemental additons" to existing soil. While the addition of salt in some situations may not be recommended in other situations the addition of NPK may be what the tree needs to increase photosynthesis thereby increasing sugar production, i.e. root development. By definition, the elements that trees need regardless of the source ARE all "chemical compounds". An organic molecule of N has the same molecular construction as a synthetic molecule of N and biological nitrogen fixation is needed to make "either" available to trees. The presence of salt or other compounds can exist in organic N or synthetic N. Fertilization by synthetic products (if done properly) is no more harmful than any other process that potentially adjusts the root development/growth or overall health of the tree. In the urban forest, watching a clients tree slowly decline due to a lack of elemental resources, due to a fear of "synthetic", "chemical compounds" is not an option.

 

[Ekka]

One process involves the use of soil bacteria and fungi plus higher chain vertebrates the other is simply available.

Did you know that only recently they're discovering how trees actually "mine" what they need. Trees actually control their exudates to influence the soil biology around their roots so that the preferred resource comes into play, so for instance if a tree needs nitrogen it will change it's exudates to encourage the type of environment that brings that resource to it .... so hypothetically microbe B comes along, feeds on whatever the substance is that was secreted, excretes it own product or dies and becomes the resource the tree uses. Natural diverse forests, like say Lamington Park rain forest here has a rich humus layer, moist shaded soils and is teaming with life. Very hard to repeat in suburbia for sure however the less reliant you make a tree on spoon feeding the better it is, and it can to a degree control it's own resources provided they're there.

Another option for an ailing tree in good soil would be say a mauget injection (or similar), leaves the soil chemistry alone and gives the tree a temporary hit as required.

az10sgal, try the calico test, it's mentioned in the PDF I loaded.

Calico test
A simple qualitative assay for general activity is the
cotton strip test. It involves inserting a strip of
unbleached calico into the ground and examining it
three weeks later for decay. The greater the decay,
the greater the biological activity.

Basically get a strip of unbleached cotton, say 1" wide and 8" long, bury it vertically with just the tip sticking out.

The above says check it at 3 weeks, should have a few holes through it, at 6 weeks should be gone.

 

[semiferger]

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