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Composting pine needles (pine straw)

Posted by DonZone8 8 (My Page) on
Wed, Aug 6, 14 at 12:50

I'm a composting newbie.

My property has "regular" leaves and pine needles (pine straw) mixed together -- about 20-30% pine straw. I've read conflicting reports about pine needle acidity and the speed of decomposition.

If I compost this mix, will the pine needles remain relatively decomposed when the other leaves have finished composting? Can I then sift out or otherwise remove the pine needles?

Do I need to supplement with a lot of other brown materials?

Or is it all more trouble than it's worth?

I have a new tumbler composter.

Thanks for any insights,

Follow-Up Postings:

RE: Composting pine needles (pine straw)

Pine needles will compost about as fast ans anything else if you keep it damp and have some source of nitrogen (greens, not browns)

HOWEVER - why not use them as mulch without composting them? It makes a nice mulch that tends to stay in place.

RE: Composting pine needles (pine straw)

lazygardens: Thanks for the reply. One problem is that the pine needles are mixed in with the other leaves.

Does anyone know a (relatively) easy way to separate the needles from everything else?

RE: Composting pine needles (pine straw)

Compost those Pine Needles right along with the other leaves. While the pH of Pine Needles is in the range of 4.0 to 5.0 the pH range of other tree leaves is in the same range and compost finishes at a pH of near neutral, 6.8 quite often. A study done some time back by Dr. Abigail Maynard at the New Haven Agricultural Research Station of UCONN found that adding Pine Needles, or Oak leaves, to soils did not significantly affect the soils pH, even over a fairly long time.
The only problem I have seen with composting the needles from Red and White Pine and Spruces is that they needles can present a problem of digestion for the bacteria if adequate amounts of Nitrogen are not added to the mix.

RE: Composting pine needles (pine straw)

Pine needles will compost in my bins with coffee grounds, but take longer, so I have to remove them if they are not decompose yet and put them back for more treatment. But, if you are cold composting them, it will take even longer to do it. Most tumblers have too small a volume to generate heat, at least that is reported to me.
Since I don't have a tumbler the pine needles are sort in big clumps, so I can just take them out. It is not all mixed up very well. But if I few stay in the compost I am using, I just let them go and they do breakdown very shortly once the compost is used. I don't fret a few of them in the finished compost.

This post was edited by tropical_thought on Thu, Aug 7, 14 at 11:08

RE: Composting pine needles (pine straw)

So, according to UCONN pine needles are of no benefit to alkaline soil? Or they will help lower the pH to neutral but not drive it into the acidic range? I ask because I'm trying to reconstitute some extremely alkaline soil, I stirred 600 liters of peat moss into 300 SqFt of garden last year and still am not at even a pH neutral level. I just mixed in 1 kilo of sulfur (amount suggested by a local garden center based on my current pH level) and will test again before planting but was going to go harvest a bunch of pine needles over the next couple of weeks.

RE: Composting pine needles (pine straw)

CypExile ... compost tends to end up close to pH 7 or so, no matter what it started with. If you have arid alkaline dirt, the best thing is liberal amounts of soil sulfur ... and more compost.

Be careful with peat in an arid climate - when it gets dry it becomes hard and dry and repels water. Getting it damp again is difficult.

RE: Composting pine needles (pine straw)

I don't know how peat moss came to have a reputation as something you'd want in your garden.

Not only is it a water-sucking dryness factory, it also has so much tanin (tannin?) in it that the Vikings used it to preserve fish on their long voyages, & a number of strikingly preserved human bodies have been recovered from Irish bogs (google bog bodies).

Some of the bodies, 800 or so years old, are so well-preserved that you can see the pores in the skin.

Preservatives *stop* organic action;
doesn't sound like anything I would want in my garden or soil.

I live in what must be the alkaline soil capitol of the world, north central Texas, & it's a lost cause to try to change the Ph of the soil on any kind of long-lasting basis, because...
the water is alkaline.

Every time we water, we're raising the Ph.

I once read an article on how to grow azaleas in the Dallas area in a Highland Park Garden Club magazine from the 1940's.

The technique involved digging a 6' deep flower bed & putting layers of straw, manure, soil, then a little sulphur, etc.

& the last sentence said that this was for a 20-year bed;
at the end of 20 years, you have to dig it all out & start over!

My experience with pine needles in my pla-doh-like alkaline clay soil is that the needles do decompose, & they improve the tilth of the soil.

I generally ignore the ph, since there's not anything I can do about it anyway, short of moving to Tyler.

Some plants are "ph adaptable";
even if they're advertised as acid or alkaline loving plants, they can adjust.

If your plants need a more acidic soil, maybe you can just apply some rose or azalea food.

I'd use the autumn leaves/pine needles mixture as a mulch & let nature take its course.

They'll eventually all rot together.

but if you want to use your composter, go ahead & toss them all in there;
Not every material decomposes at the same rate, but, again, they'll eventually all rot together.

When you harvest your finished compost, if there are identifiable pine needles remaining in the tumbler, just toss them back in, just as you would any other material that you can still identify.

There used to be a poster on this forum who composted a thick city phone book!
but she had to pitch it back in the compost pile a few times.

Have fun!

Here is a link that might be useful: Peat Moss as a Food Preservative

RE: Composting pine needles (pine straw)

Thank you, sylviatexas, for the info. I have a 2000 liter water tank and circulation pump which I bought for 10 Euros from a recently closed factory. I've it it full of water and 1 kilo of sulfur (the maximum level allowed in drinking water) this is what I am watering my Evil Sweat Generator from. My cactus in front don't get this water but maybe I'll see how they do on it as well. Lotsa roses in Tyler.

RE: Composting pine needles (pine straw)

Don't know about the drying, re-wetting problem as my clay soil seems almost water proof on it's own? BUT since adding the Peat I've broken no implements in the front and the soil doesn't seem to turn into bricks quite so readily this year. Maybe that's because we've had less rain and most of the implement breaking in front happened last year? The soil doesn't seem better but it IS looser which is a good thing, yeah?

RE: Composting pine needles (pine straw)

As I recall the soil on Cyprus is calcareous, or limestone based, so it will tend to be alkaline. For eons Cypriots have been growing food and other things in that soil so possibly a discussion with some of the elders on the island would be of some help.
Neither UCONN, nor Dr. Maynard, never stated anything that could possibly lead one to believe Pine Needles would be of no benefit to alkaline soils, organic matter will be of benefit to most any soil.

RE: Composting pine needles (pine straw)

I use pine straw for organic material in my vegetable garden. I have Alluvial fine sand. It is better now than it used to be.

RE: Composting pine needles (pine straw)

I'd guess peat *would* improve tilth, but so would pine needles, autumn leaves, even cardboard.

& all of those things will add some organic value to the soil, & none of those things inhibit organic activity.

& they're...

you know.


RE: Composting pine needles (pine straw)

Pine needles will decompose nicely if they are in contact with clay soil. From my experience, they make an ideal mulch under raspberries. I have run pine needles through my chipper/shredder and they will decompose much faster in a compost bin when they've been shredded. If you're going to put unshredded pine needles in your compost bin, I would try including liberal amounts of clay soil that's been dried out so that it can be added as a fine powder. Clumped clay soil won't be as effective.

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