Wanting to understand mulch


The research on mulching trees has always been extremely positive. Not so, the application of mychorizal products, except with soils historically devoid of tree species (such as a midwestern praerie soil). I tried to provide a link to the download that the below will bring you too with a goosearch. I couldn’t do it but it is an interesting description of research done way back in the 1940’s.

Mycorrhizae and Phosphorus Nutrition of Pine Seedlings

For most situations in areas with native trees adding mychorizae will likely not improve tree growth, but I don’t doubt it would in Kansas.

I also have invasive bindweed well established in my property. Unfortunately, even a layer of wood chips over cardboard does not keep it at bay for long. It is by far the worst of weed pests I have to deal with, particularly in my veg garden and baby tree nursery. Woven landscape fabric is a better barrier than cardboard, although it is not something I love to use at all, but it is the best of three choices for me, the other two being pulling it out endlessly by hand and herbicides. Unfortunately I can only use it in the veg garden and it is not even practical with all kinds of vegies.

Voles have to be either trapped out or poisoned out here, pretty much whether you use mulch or not. They especially love the protection of landscape fabric, it seems. However, young fruit trees are at risk no matter how you manage the ground under them and simply reducing the risk is not adequate. It makes no more work having to kill more of them.


Ditto all that. Bindweed is so bad in some places, it’s choking out my ragweed crop, lol. Glyphosate sort of works on it, but as mentioned one can’t really use it around veggies or young trees much.

For annual crops like tomatoes, I’ve been spraying the bindweed w/ glyphosate when the tomatoes are about done. If bindweed is like trees, it is moving lots of nutrients (and the herbicide) down to the roots where it can do more damage. I use Prowl as a pre-emergent which seems to slow it down too.

One good thing is that bindweed doesn’t do as well under full sized trees. I think it must need full sun.


Roundup isn’t very effective on bindweed. It knocks the top back but doesn’t kill much of the root system. The 2-4D type herbicides are better. But it takes repeated sprays over several yrs to deplete the roots. And the seeds last up to 50 yrs in the soil so it comes back as soon as one quits spraying.


Thank you those are excellent points that I’m glad you brought up. If we don’t need to apply something we shouldn’t do it. In Kansas where I live we do need these types of things applied. I always apply things with a specific purpose in mind. I had a hypothesis for example our potatoes needed azomite because they never got larger than marbles. I applied 2 cups of azomite to that potato bed and this year they were normal sized potatoes. That not conclusive evidence but over time I go by cause and result. Magnesium in my area makes trees green up better but I would say that’s not true in most places. Mulch changes our soil to grow trees better. Truthfully I have found its a bad idea in my vegetable garden to apply wood mulch because it changes soil organisms. Long term wood chips in my opinion change garden soil for the worst in my area. Cardboard, hay etc change garden soil for the better here. What’s good for growing fruit trees is not good for vegetables in my opinion.


Clark, I agree with most everything you posted and the only reason I brought up the specifics of when mychorizal supplements are effective is because they are one of the current “fairy dusts” marketed as an all purpose beneficial for all gardeners willing to pay for the products although I believe most research indicates they are of no benefit in most soils where native trees thrive or have thrived within the last 100 years or so.

Anecdotal observation only takes you so far if you stop at the point of immediate results without knowing why. Woodchips make a fine garden soil amendment IMO, provided they are well leached of any phyto-toxic chemicals to which I believe young veg plants can be very sensitive. I fail to see how they would affect Kansas soil differently than the various soils I’ve used and seem them used in here. With seedlings with roots close to the surface they can suck available N from the soil to the point of stunting plants, particularly fresh chips and particularly in wet heavy soils. However, their ultimate effect on soils is bound to be positive for most vegetables and even before breaking down the problem with N can easily be compensated for.

The less studied issue is possible phyto-toxic interactions which I believe can be very species specific on both sides (species of chipped trees and species of vegies). With young trees I’ve never had a problem with fresh chips but I’ve occasionally observed serious stunting apparently from fresh wood chips in my vegetable garden.


The reason I’m against using a large amount of wood chips in the main part of the garden against many experts advice is because gardens are not strictly fungus based soils they are bacteria. Fruit trees need fungus based soils so wood chips are highly beneficial to trees http://permaculturenews.org/2014/05/07/fungal-soil-want/. I have applied wood chips in the garden but just 4 years ago so my soil may be different than other peoples meaning I don’t need or want more of those particular soil organisms. My belief is unless a garden is void of organic material and nothing else is available there is not a need for wood chips and there are better things to use such as grass clippings on a yearly basis. That’s not to say wood chips are not beneficial once in awhile. My organic matter is very high in my garden because I use cow manure , hay, etc. I’m also assuming most of us are using no till gardens because we all know the negatives the wood chip have temporarily on nitrogen should they get into the soil. I grow (as your likely aware) large quantities of mustard etc. so in my situation with my soil Mycorrhiza is less beneficial to my garden than someone else. I was being lazy and not fully explaining my logic and for that I apologize. Soil science is very complicated and still not fully understood but these are the basics for other readers https://en.wikipedia.org/wiki/Soil_biology. The benefits of the trace minerals of wood chips I have already applied in the form of azomite http://www.azomite.com/. This article explains it better than I can http://extension.illinois.edu/soil/SoilBiology/fungi.htm. Every plant needs different amounts of fungi and 50% of what I grow is in the Cruciferae family which does not benefit from the fungi found in wood chips at all. With all that said keep in mind I could see how wood chips would be beneficial to other people in their gardening situations.


I’m sorry Clark but your first link leads me to what strikes me as science babble- not even to the level of pseudo-science. Absolutely no research references so I can’t accurately evaluate the sweeping statements made, but I certainly have decades of contradictory anecdotal evidence… When one clears a forest soil of trees, productive annual crops can generally be grown in it instantly, and, in fact, productivity is likely to go down after a few years of cultivation as organic matter declines. When I grow annuals in a medium of half sand and half composted wood they thrive.

My success as a horticulturist began in CA when I began mixing oak compost with the sandy soiil at a 50-50 ratio. Such compost is like medicine for annual plants in my experience. The first half of my life required the success of wood based compost in stimulating the growth of annual plants for my entire income.


This article discusses the fungi / bacterial relationship I’m doing a bad job of explaining http://www.biodynamics.net.au/articles/51_BD_and_soil_food.pdf. You might or might not agree with the overall topic but it does a good job of explaining my perspective on bacteria vs. fungi based soils and the types of things grown using each type of soil.


OK, read it, but in the real world I grow in, “highly fungal” soils do not appear to be barrier to productive and vigorous growth of annual plants if the soil is at the proper pH- a very simple adjustment in slightly acid forest soils. I would like to see research as opposed to logical seeming explanations on this topic simply because my own experience strongly and unanimously contradicts the claims being made.


Here is the kind of stuff you can buy from www.biodynamics.net.au

Horn Manure (BD 500) 1kg
Horn Manure Prep 500 is the original biodynamic soil spray and is made from fresh cow manure, buried in cow horns over winter. It is a powerful soil activator helping root development and growth of the plant as well as humus formation in the soil. $130.50

Hey folks don’t miss out on 2.2 lbs of cow manure for only $130.50.

This isn’t science it’s salesmanship.


The person being direct quoted in that article from the biodynamics website referred to is highly respected Dr. Elaine Ingham. What else they sell on their website does not take away from her expertise in the field. This is her linked in account https://www.linkedin.com/pub/elaine-r-ingham/6/52b/96a. This is the .gov article that states what was said about bacterial vs. Fungal based soil types http://www.icbemp.gov/science/ingham.pdf. This is her speaking on soil fertility at the Oxford Real Farming Conference https://www.youtube.com/watch?v=pDtGxOdDj1A. She is definitely a scientist. She may have a different point of view from other experts but that does not detract from the validity of her research.


I doubt anyone has done conclusive research for or against either method. Soil needs are different in almost every situation.


So Clark this lady formerly worked at OSU and now the Rodale Institute. I’ve seen that before. Escape the crush of university, publish or perish, peer reviewed research for a cushy special interest job.

I’m not saying soil health isn’t important, it is. Nature has a system millions of yrs in the making: the tree feeds the soil and the soil feeds the tree. That’s basically what I do. With very minimal inputs my soil has high water intake and great structure. My trees are healthy and my fruit has been well documented on the internet for yrs. I don’t think anyone is growing better fruit than mine.


Fruitnut is soooo humble. :stuck_out_tongue: lol


Isn’t there a saying something to the effect: It’s not bragging if it’s true. Maybe I’ve got that wrong but guess what at my age I don’t care anymore. Anyone reading the fruit and orchard forum on the gardenweb for the past 10 yrs knows what’s up.



“It is not bragging if you can back it up”. I’ve read Garden Forum since 2009. You are not bragging.


Noone is questioning your fruit growing results. I’ve learned plenty from You, Scott ,Alan and others through the years. Woodchips always bring up difcerent schools of thought eg. Alleopathic chips such as cedar some say are harmless others say harmful etc. I guess we all grow excellent fruits and veggies even if we have different methods at times.



I don’t hear of much use of 2-4D in orchards presumably because of leaching potential to fruit tree roots. Have you ever used 2-4D around fruit trees and noticed any problems?


Only around grapes once and that was a big mistake. I’m not recommending it around fruit trees by any means. My experience is in crops like wheat and sorghum.


Clark, I just looked up your doctor on google under the words “Elaine Ingham research” and instead of finding any actual studies she has led I find pages of promotional material of stuff she wants us to buy or articles in magazines with a strong new agey feel to them. She has made herself a product and does no work with any universities. She left Rodale last year and Rodale recently released a study debunking her claims about compost tea.

I had written a couple paragraphs dissing biodynamics, but rereading your comments i realized that you were not endorsing their methodology only the Dr.'s article.