Should weeds go in the compost pile, especially those with seeds? This question is bound to arise in midsummer as a bumper crop of weeds hits most gardeners. Here are some thoughts on the matter but you have to make up your own mind.
First of all, it would appear that weeds that have not gone to seed would all be safe to use for compost. However, the gardener needs to look at the plant itself. Chances are that an annual weed that has been uprooted and the roots allowed to dry will be dead before it hit the pile. Perennial weeds are a different sort all together.
Their roots are likely to survive a long time. In appearance they will often be white and thick with moisture retentive properties, ready to wait until circumstances allow them to sprout and spread, circumstances like the edges of a compost pile with warmth, moisture and food. Actually, they may be more trouble than weeds with thousands of viable seeds.
After all we are told that every cubic foot of soil has millions of seeds. Even if there is only one million weed seeds in a cubic foot of your garden soil, and that only the ones in the top inch will sprout, that means that there are five hundred seventy-eight weeds ready to sprout in every square inch of garden soil. How much difference will a few more seeds per cubic foot make?
Balance this with the knowledge that those weeds represent a great source of nitrogen for the compost pile. Plus, their roots have gone deep and long to capture a lot of mineral content for the soil which you can now move into the bins to enrich the topsoil later. Just as carrots and corn will gather both similar and different things from the soil, so do different weeds and thus a good mix of weeds for the compost pile implies a richer pile by far. Also the quick composters must remember that a fast pile is a hot pile and this will kill a lot of the seeds and the perennial roots as well.
So the plants that we call weeds may be a nuisance in the garden but a treasure in the compost bins. As the mystery of composting happens in the back yard, the treasure of weeds becomes the black gold of compost. -Darrell Feltmate
I find this to be a somewhat confusing article…or at least that it further solidifies my position that composting to most is an art. He states that weeds are the “black gold” of compost, which is quite a bold claim. I like that he lays out the fact about millions of seeds being in every foot of soil…but there’s also millions of types of seeds, no?
I don’t want weeds in my compost. They suck up the moisture from the rest of the pile, especially if they’re near the top. Even if the roots are high in mineral content, I have plenty of other sources for minerals instead of weeds.
Even after stating this, I find it funny because in the end we’ll both have awesome compost piles to play with.