My husband has piled grass clippings and chopped leaves in our side yard for 2 years. A few weeks ago, I decided to try my hand at composting. I divided the pile into three sections so that I could realistically keep it turned. I also added a couple shovels of dirt to section #1. Surprisingly, section #1 is "cooking" very well after I started adding kitchen scraps. I'm wondering if the dried out grass still has nitrogen to give or if it is considered brown. At what point to I stop adding kitchen scraps and start another pile with them? Thanks.
When they are dried out ,just like the look they are a brown,I don't know about the scraps as throw mine in a hot or active pile,that will eat up an old head of about anything in about a week and a half, cool huh!!?
I don't know it from experience or reading, but I agree with Juhur that dry, brown grass clippings have l;ost most of their nitrogen, so they count as brown or near-brown.
I would assume / expect them to "cook" fast for four reasons:
- they are fine and thin. thin things cook faster in a compost heap
- they do have some N left in them
- they already broke down part way as they dried out, years ago
- they are soft, not woody. Stiff woody things (and waxy things) break down slower.
>> At what point to I stop adding kitchen scraps and start another pile with them?
If you have plenty of browns and only a few scraps per week, I would encourage you to run your heaps "lean". Only give as many scraps as necessary to get the clippings to change from individual brown threads to crumbly black stuff that no longer looks like dry grass. When iot looks more like soil than like drylawn clippings, it is totally ready to use.
The tradeoff is that you might want to let your heap "cook" longer to break down any woody twigs and chips or added paper.
Also,the longer you age your compost, the more weed and other seeds will be eaten, or sprout and be eaten, or rot. That way you add fewer weed seeds into your garden.
If there were long-lasting general herbicides on your lawn, more composting time gives them more time to break down. If you add a lot of weed-killer to sensitive plants, they won't like it much.
Finally, for some reason the conditions in compost heaps seem to encourage beneficial microorganisms more than ones that harm plants. My guess is that plant pathogens are evolved to invade living plants and thrive in their tissues. Soil and compost organisms are evolved to live in soil and digest dead plant parts ... and each other ... and any plant pathogens they encounter.
Most people won't add ANY visibly diseased plant parts to a compost heap at all, but a hot heap that you let digest for along time seems to digest many of the disease organisms along with plant matter. Probably most people are SMART to throw away anything obviously diseased. So the wiser path is to throw away anything diseased with things that seem to be a problem in your climate. (If it just has a few spots, or it started to die and THEN looked sickly I compost it, wisely or unwisely. Rick needs compost!)
My theory is that if I am choosing between burying slightly sick raw plant parts right under something's roots, or composting that thing first, it carries fewer plant pathogens back into the garden if I compost it first.
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On the other hand ...
The sooner or "younger" you mix compost into the soil, the more nutrients and organic carbon you feed to your soil organisms and plants, as opposed to feeding them to the compost heap organisms. During composting, some nitrogen and CO2 are lost. That's why some people skip the compost heap altogether, and spot-compost garbage right into holes dug right in their garden.
I prefer to compost garbage and coffee grounds and green plant clippings. It lets me use their nitrogen to digest woody plant waste, chipped wood and paper. That way, I add the organic matter of the wood and paper into my garden without causing complications due to their stealing nitrogen from plant roots when they do break down ("N deficit").
Also, burying raw garbage in my pretty raised beds just feels icky.