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Mulching around fruit trees

Posted by sfg_newbie 6 (My Page) on
Thu, Dec 13, 07 at 13:31

I'm planning to plant a small (ie 4-6 dwarf trees) orchard of fruit trees in the Spring. I'm wondering what to use as mulch around them (I'm planning to mulch the entire area between the trees so I won't have to mow there). I have an abundance of leaves in the fall, and an abundance of fallen branches in spring.

My question is, is it reasonable to spread the leaves as mulch in the fall, and then cover them with a layer of chipped branches in the spring (so they look more attractive and I can use up all those darn chipped branches)? It would all eventually break down anyway, so I shouldn't really have to worry too much about it getting too deep. Plus, it would enrich the soil as it breaks down. Does that make sense?


Follow-Up Postings:

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RE: Mulching around fruit trees

g'day,

we sue spoilt hay type mulches where we can ie.,. luceren hay or pasture grass hay (and seeds are never an issue as we mulch to around 20"s deep).

for convenience we are using sugar cane mulch at present.

len

Here is a link that might be useful: len's garden page


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RE: Mulching around fruit trees

Wood chips that had previously been allowed to age a bit worked well for me around crab apple trees and a peach tree.


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RE: Mulching around fruit trees

May I suggest heavy stones on top of the root ball after planting. This will prevent movement of the root ball in the planting hole and prevent breaking off of the fine roots that are growing into the soil.

This has a couple of additional benefits. The stones will act as a mulch if you have no other material. Also keeping the root ball steady will allow the tree trunk normal movement and development that does not happen when the trunk is staked.

Your plan to mulch with leaves and wood will of course be beneficial.


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RE: Mulching around fruit trees

Thanks everyone!

I was just wondering if I should also spread grass clippings in a thin layer over the leaf/chip mulch. Would that help or hurt? And would it be too funky to walk on?


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RE: Mulching around fruit trees

A thin layer of grass clippings should be o.k. unless the grass clippings have pesticide or herbicide in them. A thin layer of grass clippings should disappear fairly quickly, at least in warmer months, but might be a little slippery until they decompose.


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RE: Mulching around fruit trees

I don't want to be a negative Nancy, but you may want to reconsider using the chipped branches. The leaves are a great mulch, and I would chop them up before applying. They'll add vital organic matter, reduce weed growth, and conserve moisture. Make sure you give some N

The wood mulch on the other hand brings a couple problems with its use. It has a very high carbon to nitrogen ratio, so it lasts a long time but will tie up nitrogen in your soil, also for a long time. It breeds artillery fungus, something you won't need to worry about unless your trees are close to any of your property. Artillery fungus will shoot spores high into the air where they will attach to your siding and car paint. It's nearly impossible to remove. The wood mulch could also harbor disease from the tree it came from. Your whole orchard could be infected. Try compost for a mulch that does it all: feeds, inhibits weeds, suppresses moisture and disease, and conserves moisture.

You could always use the wood chips anywhere you won't be growing plants. Try using it for garden paths or any other walkway away from your house and car.

I know this all sounds rather much, but you have quite an investment in that orchard. Best to err on the side of caution. Good luck.

M


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RE: Mulching around fruit trees

My fruit trees are mulched with shredded leaves and wood chips, although I've not plunked grass clippings down since I never pick any up. I do need to add some manure periodically, for nitrogen, but whether that is because of the sandy soil I have or the needs of the soil bacteria digesting the wood chips I'm not real sure, just that the trees don't blossom or fruit quite as well if I don't add the manure.
I have not seen any artillary fungus growing in any of the woody mulches I have, I have never seen an plant disease because of the woody mulches I use, I have never seen a problem with using woody mulches that people that have never used them seem to think they will generate. Like any other mulch material woody mulches aid in soil moisture conservation, in suppressing "weed" (unwanted plant) growth, and in keeping the soil cooler which your plants like, as well as slowly, over a long period of time, adding organic matter to your soil. Leaves will do the same, but are digested faster. Stones do not add any organic matter to soil and can cost large sums of money, but do not need to be replaced periodically. However, I have seen soils under stone mulches becoming anaerobic because of the lack of air exchange.


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RE: Mulching around fruit trees

Wood chip mulches do consume some nitrogen in the top inch or two of your soil. Wood chips here take about 3 years to compost when spread at about 4 inch depths. At that time their use of nitrogen has turned from negative to positive and in most soils I don't think for orchard use I would be concerned. Using large rocks as a mulch around a newly planted tree would in all but the sandiest soils, be a cause of soil compaction and loss of oxygen in the root zone, not a good thing for tree or root growth. Al


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RE: Mulching around fruit trees

While I have gardened for years, I'm new to the study of soil. Working on improving my lack of knowledge is my main project for this winter. I am reading a book on soils called Teaming with Microbes right now. I'm halfway through at this point, but I got the impression that we want all those fungi decomposing wood chips. Aren't they mostly beneficial? I do understand that they reduce nitrogen in the top inch or two for the first year or two or three, depending on how finely chipped they are.

Rosefolly


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RE: Mulching around fruit trees

Newbie, if you feel the leaves have come from where they have lain a long time, possibly where they have picked up disease pathogens, then it is suggested to not use them around your fruit trees.
In any case, keep any mulch away from the base of the trees.

Mulch is a great place where insects and disease can take refuge. Winter is not going to remedy that.
They will find a way to live til spring when the larvae that has come from eggs laid in the fall emerge and your fruit trees will make a fine place to reside in.

So keep the mulch at least a foot or two away from the base of the tree.

If you are planning an orchard, then you will have cause to do dormant oil spray applications to kill overwintering pests and disease.
After that, you will, of course, follow a strict guideline on fruit tree spray applications throughout the seasons at the appropriate times.

Any fruit tree spray bottle will guide you on when and how to spray for the benefit of the trees and the fruit.
Your first application though is the dormant oil/lime sulfur application made when the temperatures are above fifty fahrenheit, when rain is not forecast for at least 48 hours....and nighttime temperatures do not fall below 32.


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RE: Mulching around fruit trees

You're right, fungi decomposing the wood mulch is a good thing. They're the main decomposers of wood mulch and good for your soil. There are many types of mycorrhizal fungi that form symbiotic relationships with your plants and help deliver water and phosphorous. The artillery fungus though can stain anything within "shooting distance." Like I said, you really don't have to worry about it when the mulch isn't near your property. Don't believe me? Read for yourself here. Check the archives on this site for more about mulch.

M

Here is a link that might be useful: About Wood Mulch


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RE: Mulching around fruit trees

People that have relatively good, healthy soils need not concern themselves with plant diseases since plants growing in good, helahty soils are better able to ward them off than plants growing in the unhealthy soils some people must have to be so concerned about that problem.
Sometimes people have seen growth problems when using mulch material purchased at stores, generally not something that need to be done given the abundance of free mulch material, however, more often than not these problems back be traced back to the soil and a lack of nutrient balance in that soil. Spending some time with this Soil Food Web Primer can help people understand what is happening in their soil.

Here is a link that might be useful: The Soil Food Web Primer


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RE: Mulching around fruit trees

I'm not sure where some of these posters are getting their information, but if you do the research, you'll find a great deal of documentation on the benefits of wood chip mulches, especially as applied to woody plants (trees and shrubs). Nitrogen unavailability has not been shown to be of significance with regards to woody plants unless the mulches are incorporated into the soil and there is no scientific evidence to support the contention that disease pathogens are spread or encouraged by wood chip mulches. The benefits of ANY organic mulch and the pluses of recycling what is typically considered to be a waste product (fallen branches/prunings/brush) override any potential drawbacks. Plus, wood chip mulches are slower to break down depending on chip size and do not need to be replaced as often as finer sized or more easily decomposed mulches. The only caution is to keep any mulches from direct contact with trunks or stems - 2-3 inches away is sufficient; 1-2 feet is unnecessarily distant.

The need for dormant season spraying is not automatic. There are scores of disease resistant tree fruit cultivars on the market and insect problems need to be present and identified before any treatment is advised. Developing a healthy soil and practicing good garden sanitation will often prevent the need for any regular spray program.


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RE: Mulching around fruit trees

there is no scientific evidence to support the contention that disease pathogens are spread or encouraged by wood chip mulches.

I would agree that, generally speaking, wood mulch as a source of inoculum isn't a huge concern but I wouldn't go so far as to say that there is "no scientific evidence...."

There's this:
"Cankered branch pieces were placed into mulched areas surrounding honeylocust trees growing under two irrigation regimes. Thyronectria austroamericana recovered from cankered wood pieces after 98 weeks produced cankers when inoculated into branches of honeylocusl trees. Irrigation regimes did not affect recovery of the fungus. Cankered wood pieces remained a source of inoculum for 143 weeks after placement in the mulched areas."
From Journal of Arboriculture, May 2004 by Koski, Ronda, Jacobi, William R

And then there's this:
"Verticillium wilt is a serious problem of trees, especially maple species. This research shows that V. dahliae can survive in mulch, compost, and is a source of inoculum for susceptible plants."
From G. L. Foreman, Douglas I. Rouse, and Brian D. Hudelson, Department of Plant Pathology, University of Wisconsin

On the whole I do agree with you but there is a pretty big gap between limited evidence and no evidence at all. That's only what I dug up in a quick google search.


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RE: Mulching around fruit trees

You're right - that was perhaps too much of a blanket statement :-) However, there is very little literature that supports the contention that disease pathogens are easily spread through the use of wood chip mulches. And there is even less of a concern if the mulch is derived from known sources that are apparently disease-free.

In support, I'd offer the following report by a local extension head and horticultural professor and researcher:

Here is a link that might be useful: wood chip mulch myths


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RE: Mulching around fruit trees

Like I said, I pretty much agree with you. When I hear anything stated as an absolute though, it flips a little switch in me and I just gotta say, "Hey, what about....". It's like an illness or something. ;)


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RE: Mulching around fruit trees

Kimm, I just recalled what they call you. "Cass"...John Cass ---isn't it?

I'll call you Jack.


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RE: Mulching around fruit trees

  • Posted by whip1 z5 ne Ohio (My Page) on
    Sun, Dec 16, 07 at 2:15

Jeannie, in another thread, you mentioned that name calling violates the terms of use. You clearly know the rules, so why are you breaking them? I think they have a name for that also.


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RE: Mulching around fruit trees

is it reasonable to spread the leaves as mulch in the fall, and then cover them with a layer of chipped branches in the spring

Perfect. That is what I've been doing for 30 years and it has worked wonderfully so far. ::smiles his jolly smile:: Just leave it right on top of the ground, you do not need to work it it.
Grass trimmings are ok to, but may lock up nitrogen. The first year with new trees you don't want to come up short of nitrogen, so if you use grass trimming, you may also want to use some bird or horse manure.


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RE: Mulching around fruit trees

I've never heard of grass clippings being a problem with tying up nitrogen when used as a mulch. I expect them to be considered a source of nitrogen more than a nitrogen immobilizer. They have a much lower C:N ratio than leaves or wood mulches and would be a good alternative to protein based fertilizers for balancing high carbon materials.

M


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RE: Mulching around fruit trees

Gardengal,

Your link made me laugh when I saw that name...

Linda Chalker-Scott, Ph.D intentionally tried to discredit the use of aerated compost tea. She specifically asked for E.Coli infested unfinished compost for brewing just to discredit compost tea as a whole. She didn't even mention that part when she showed the study to the public...


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RE: Mulching around fruit trees

  • Posted by rdak z5MI (My Page) on
    Wed, Dec 19, 07 at 14:59

I've never had a problem with wood mulch around my fruit trees FWIW.

Yes Lou, I started to worry when Chalker-Scott said diseased wood chips are no problem. Now I wonder?! LOL!!

Her compost tea study was dishonest and laughable IMHO.


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RE: Mulching around fruit trees

  • Posted by pt03 3 Southern Manitoba (My Page) on
    Wed, Dec 19, 07 at 15:57

My story is somewhat different. I used several tons of chipped Xmas trees as a mulch on some Saskatoon seedlings (2 years old)in the field. I only did two rows of about 175 trees per row. About 2/3rds of them died. The adjacent rows with no mulch had a normal 10% die off over the cold season (afraid to use the word winter). I have no idea what caused the kill off of the trees with the mulch. The wood chips were relatively fresh, I was just using them for moisture retention. The saskatoon is susceptible to the wooly elm avid and maybe the mulch provided protection, I have no clue. Might be a coincidence. I did put a bunch of aged chips around the cherry trees when they were older with no ill effect. Not much help for you but that is what happened to my trees.

Lloyd


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RE: Mulching around fruit trees

Lloyd, thanks for posting your experiences. Obviously, you expected the wood mulch to help the trees. Obviously it had the opposite effect.

What I find so interesting about this is that the 'expert' advice for so long has been to lay down this sort of chipped wood mulch. Now it seems clear that these mulches are actually bad for the soil.

I'm going to guess that chipped wood needs to be aged, or composted for a year or more before use.


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RE: Mulching around fruit trees

Lloyds experience may be related to the mulches or any of a number of other problems newly planted trees are subject to. One of the research papers quoted above indicates that the disease pathogen was innoculated in to the trees, not that the trees got the disease from the mulch, while the other states that the disease pathogens can survive in mulches but not that any plants actually were infected from the mulch.


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RE: Mulching around fruit trees

  • Posted by pt03 3 Southern Manitoba (My Page) on
    Thu, Dec 20, 07 at 13:17

I seriously don't believe the die back had anything to do with diseases or pathogens. It might have something to do with the pests (aphids) i.e. providing more shelter for them but this is speculation. I had considered a nitrogen problem as well. The area where the most trees survived was on better soil. Once again I have no evidence of what caused the die back but it was only the rows with the chipped xmas trees that suffered such losses.

Lloyd


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RE my comment about grass locking nitrogen, around here grass trimmings are usually the dry woody stuff when the scalp lawns for fall rye plantings. That sort is very brown and locks nitrogen. Sorry I wasn't thinking of the fresh green stuff you may have. The fresh green will not be a problem, use it.


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LLoyd, since the are where the most trees survived was "better" soil and the area where the most trees died then mist not have been "good" soil what did a good, reliable soil test have to say about the nutrient load in those soils? If no soil test was done then the cause of death could have been any number of other problems unrelated to the mulch. Without that good, reliable soil test you cannot state that the only difference was the mulch because you simply do not know enough about the soil.


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  • Posted by pt03 3 Southern Manitoba (My Page) on
    Sat, Dec 22, 07 at 7:06

Kimmsr, perhaps if one thinks of "good", "better", "best" one can imagine the soil in a field. The north end of the two rows of trees is somewhat better soil, that area had the least die back but it still had die back. The south end soil is not quite as good and it had the worst die back. The rows immediately to the east and west that had no mulch applied had normal die back along the entire length of the rows. These rows are only 18 feet away, they were planted at the same time and they are the same kind of seedlings.. Trust me, the mulch somehow contributed to the die back. As I stated twice already and now for the third and last time, I do not know what caused the increased mortality but the mulch had something to do with it.

I understand you are a soil test proponent, I have seen the several hundred references you have made regarding it therefore I understand your point of view. I didn't intend to get into a 10 post discussion about my trees.

I applied mulch on some trees, those trees had a greater mortality rate than those that did not get mulch applied, the mulch somehow contributed to the increased mortality. Cause not known.

Lloyd


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