Wood chips to hill potatoes???

[freddiefalcon]

Are there any problems associated with using wood chips to hill potatoes? I am not talking about including any wood chips below the soil line. I know this can rob plants from the nitrogen they need.

All of my wood chips would be above the soil line and would be primarily used to protect against any potatoes that protrude the soil. I used straw last year with good success, but this year I have access to an abundance of free wood chips. I couldn't find a lot of agreement on the web searches I conducted (some people say no problem and others say it is not a good idea).

[stevecrouse]

There were some studies done by Cornell U a few years ago using wood chips as a soil amendment.
The size of the chip, with a fairly small surface area, means that it is not the nitrogen hog that something like sawdust would be, making it a a slowly disintegrating, water holding material.
The study was never finished beyond those conclusions as far as I know.
If I were to try it, I would definately stay away from pitch laden woods such as pine, spruce, and fir.

[paquebot]

Used for hilling potatoes, wood chips will not affect the plant growth any more than if hay, straw, sand, or shredded rubber or plastic is used. The roots are not up where the tubers are being formed. Since I have common scab in my gardens, I hill with a mix of 50/50 soil and fine-shredded Christmas tree boughs. That combination is acidic enough to deter scab. It's only good for one season and then breaks down to humus. Much cheaper than having to add a lot of sulfur year after year.

Martin

[jimmie the spud]

Do a row with woodchips, and see how it compares to the rest.I don't trust what I hear or read fully until I've tried it myself.I know of people who use nothing but and get great results. I prefer mine previously composted, but may rethink that.

[paquebot]

Most common mulch for potatoes is straw. Seed pieces are planted shallow and covered with up to a foot of straw. Tubers develop only in the straw and about guaranteed to be clean and have no scab. Straw and wood are comprised mainly of the same element, carbon. One is no worse or better than the other. If shredded pine boughs are used, there's the advantage of a high percentage of nitrogen which would not be present in straw or plain wood.

Martin

[freddiefalcon]

Jun 5, 2013 16:43:25 GMT -8 stevecrouse said:

There were some studies done by Cornell U a few years ago using wood chips as a soil amendment.
The size of the chip, with a fairly small surface area, means that it is not the nitrogen hog that something like sawdust would be, making it a a slowly disintegrating, water holding material.
The study was never finished beyond those conclusions as far as I know.
If I were to try it, I would definately stay away from pitch laden woods such as pine, spruce, and fir.

Thanks for the information. The Cornell U study sounds very interesting. It is too bad they didn't go beyond those conclusions.

There is an online film called "Back to Eden" that I watched recently and found very interesting. It focuses on the natural decay process of a forest and how that process can be applied to gardening. The film also promotes the use of wood chips due to their water holding properties. They primarily suggested using wood chips as the top layer of any type of compost that is used in the garden.

Pine, spruce and fir aren't too much of a concern in my area. We primarily have wood chips from maple, oak, etc.

[freddiefalcon]

Jun 6, 2013 17:30:19 GMT -8 paquebot said:

Most common mulch for potatoes is straw. Seed pieces are planted shallow and covered with up to a foot of straw. Tubers develop only in the straw and about guaranteed to be clean and have no scab. Straw and wood are comprised mainly of the same element, carbon. One is no worse or better than the other. If shredded pine boughs are used, there's the advantage of a high percentage of nitrogen which would not be present in straw or plain wood.

Martin

Thanks Martin! I never really stopped to think about straw and wood being comprised of mainly the same element. Straw worked extremely well for me last year. I only had 2 or 3 potatoes with any green spots. I assume I didn't have the straw thick enough in those few areas.

[containergrower]

although straw and wood are both primarily carbon, they support very different microflora when composted or when used as a mulch. Wood chips last longer and tend to favor microflora that might stimulate more flowers than straw does, once the chips are actively colonized and have been in place long enough.
Straw has a much larger surface area than chips in relation to total volume, AND it has far less lignins than chips, so it decomposes much faster & robs considerably more nitrogen than chips do.
This is an area I have recently begun learning about, so am no expert; but I HAVE learned that without the microflora that converts nutrients to bioavailable forms and feeds it to plants' roots, there is minimal growth with very little vigor.
Feed the soil, providing as many beneficial micro-organisms as possible, and it will feed the plant.

I'd think using wood chips would be better than straw over the course of several years because the chips will do more to improve soil quality as they decompose and become humus, while being habitat for a vast array of mostly-beneficial fungi and bacteria.

this forum is teaching me So much. thank you, Tom!

[paquebot]

Wood chips indeed are a better choice for long term soil amending. They eventually break down to humus and that may last a thousand years in the soil. The smaller they are, the quicker they break down. During the winter, I collect discarded Christmas trees. The boughs are stripped off and the trunks become poles for bean tepees. (In addition to potatoes and tomatoes, I also grow about 35 varieties of pole beans,) What remains are the soft boughs and needles. As soon as it is warm enough, they are run about 3 times through a bagging/mulching mower. The results are something more green than brown and little bigger than a piece of oatmeal. There's enough nitrogen in that combination which would allow it to compost on its own with nothing added. Incorporated 50/50 in the soil above the seed piece, they are barely recognizable in the fall. And since they have completed their process of breaking down, they are no problem when tilled in. I ran short this year as 25 white pine did not give me enough for the 192 total hills. Neighbor cut down a huge maple tree and prepared for a major project to clean up all of the chainsaw sawdust. Instead, 9 very heavy bags were filled via my bagging mower which made it even finer. That will be about gone when the potatoes are dug in the fall. And, won't be any problem in 2014. Unlike the pine, very little nitrogen in it but the small size allows it all to be consumed in one season.

Martin

[GunnarSK]

Jun 9, 2013 19:35:37 GMT -8 paquebot said:

Neighbor cut down a huge maple tree and prepared for a major project to clean up all of the chainsaw sawdust. Instead, 9 very heavy bags were filled via my bagging mower which made it even finer. That will be about gone when the potatoes are dug in the fall. And, won't be any problem in 2014. Unlike the pine, very little nitrogen in it but the small size allows it all to be consumed in one season. Martin

Did you use fertilizer with that maple sawdust?

[paquebot]

Jun 21, 2013 2:27:18 GMT -8 GunnarSK said:

Did you use fertilizer with that maple sawdust?

No fertilizer added. The sawdust was spread atop shredded oak and maple leaves which I used to fill the valleys between potato rows. Elsewhere it was applied atop the same combination which is used to mulch other vegetable varieties. By being almost totally broken down by fall, the sawdust will be close to neutral humus by the time it is plowwed under. In the case of using it when hilling, and mixed 50/50 with soil, there is virtually nothing left when tilled in the fall.

I might add that how fast it breaks down depends upon how small the material is and how much rainfall is involved. In dry climates, it will last longer but help by retaining any moisture. Thus it is a benefit under either condition.

Martin

[Deleted]

You would want to make sure there are no Black Walnut, or any Walnut chips for that matter, to avoid alelopathy from the juglone. As far as I know composting degrades the toxins. Although I am just learning about this since we have lots of Black Walnut trees on our property.

[paquebot]

The walnut mention is the prime reason why I prefer to make my own chips and sawdust. Although there isn't much juglone in old walnut wood, there would be some in new bark or branches. Normally not enough to make a difference but not needed if a plant is stressed from something else.

I'm also not too worried about some of the wood not being entirely reduced to humus and removing nitrogen from the soil. Potatoes don't need as much nitrogen as many other garden plants. For 11 years I worked for a fertilizer company and our potato formula was 5-10-30. Although there aren't many nutrients in wood chips, what's there is what the potatoes need and that's potassium.

Martin

[stevecrouse]

WOW!
The fertilizer I use is either 10-10-10 or 14-14-14.
We here in Maine very rarely side dress more N later in the season unless, like this year, there is substantial rain fall resulting in N leaching.

[paquebot]

Nothing wrong with a 1-1-1 ratio. I also think that the high potassium need is a regional ing. For corn, a 1-4-4 ratio was for most of Wisconsin while 1-4-2 was for the 50 miles and Northern Illinois. It depended upon where the glacier stopped. It brought down a lot of potash but then washed it all south. The official potato sites from different states and each will give different advice. The average might be something like a 2-1-4 with less phosphorus than most vegetables. I've generally relied on oak leaves and/or horse or pigeon manure for fertilizer and done quite well. Now and then I'll till in some muriate of potash to cover the natural deficiency of that.

Martin