Can I Compost Weeds? Chicken Manure? Sheep Manure? How Moist?
Question
July 30, 2016
I am new to gardening and my question for a compost pile is: Can weeds be used in the compost bin? If so, are there any specific ones that should be avoided?
I’ve been working on my bin for a couple of months now, just adding material as it is available and before I found your site with information specific to New Mexico. I may not have kept it wet enough, I’m not sure. I have added a small amount of chicken manure (free range). Is that acceptable? How about sheep manure? I haven’t used it, but some of it is available to me.
I would appreciate any information you can provide. Thank you.
Answer(s)
Answer by JZ: Excellent!
* Weeds without seeds may be added to a composting operation. Fresh weeds are a source of nitrogen. A large pile of weeds should be bulked with coarse bulking materials to prevent compaction as they are very moist.
* Weeds with seeds already formed are best avoided. Noxious weeds with seeds, e.g., puncture vine (goat heads) and sand burrs should be avoided. Parts of the bindweed plant and Bermuda grass are best avoided.
* Alternatively weeds with seeds may be placed in a plastic bag, put in the sun until the contents liquefy. That would destroy the seeds. Then add to composting operation.
* A well managed hot composting operation will destroy seeds. My sense is that you have a cold composting operation, that is fine.
* Your composting operation should be in the shade. Maintain 50% moisture at all times = to the moisture content of freshly brewed coffee grounds. Sprinkle as necessary. Cover the top of the pile with a piece of plastic. See our brochure about Composting in the Desert.
* You may add any manure from vegetarian animals, so chicken and sheep manure are OK.
* We suggest leaving out cat, dog, pig manures, as they may contain diseases that are communicable to humans. They could be composted separately, then the end product used around ornamental plants.
Hope this is helpful.
Answer by JH: Since I coordinate the compost systems we maintain at the County Extension Office and Albuquerque Garden Center, I can explain how we handle weeds.
At both locations we attempt to build a hot pile in which the temperature will maintain 150 degrees for a period of time. This is not always accomplished and as a result most of the time, both piles are cold piles. For this reason, we do not put bind weed or Bermuda grass into either pile. We also will not knowingly add diseased plants.
Manures are good sources of nitrogen and can be composted. However, if the animal feed contains herbicide which is likely if it isn't organic, the chemical can remain active for as much as three years. Any such compost applied to a garden bed can potentially kill or otherwise harm plants. For this reason, we do not use horse manure or other manures if we cannot confirm the absence of herbicides.
My backyard compost pile contains chicken manure. The chickens receive organic feed and various kitchen scraps that may or may not be organic and I have not experienced any problems using their composted manure.
I applaud your efforts and encourage you to attend one of our classes. Desert composting is made easier with the helpful hints required to keep compost piles moist in our harsh, dry environment.