People who have gardens or yards may have heard that they should never put weeds in a compost pile or heap. The reasoning is that even in a hot compost pile, the temperatures will probably not get hot enough to kill all the weed seeds. While there is some truth in this, there is a way that weeds can be composted. It makes no sense to throw away the weeds if they can be used.
The truth about hot compost piles
The center of a hot compost pile produces temperatures of up to 140 F to 150 F. For most weeds, this is sufficient to kill weed roots and weed seeds. The problem is that the farther you go from the center, the cooler the pile gets. Even if it is turned and mixed well, some weed seeds will probably survive. Using the compost then means that you will be adding weed seeds anywhere the compost is being used.
Chopping the weeds isn’t the answer
Using a mower with a mulching blade is a great idea, but it still doesn’t get rid of the problem of viable weed seeds and roots. In fact, the problem can be made worse. Many weeds can grow from only a small amount of the root. A lot of weeds also have very small, hard seeds that aren’t destroyed by using a mulching mower.
Cook the weeds
A simple answer is to cook the weeds, roots and all. To do this, you need a very large pot and something to heat it over. This can be done on the stove, but it can also be done over a burn barrel.
The method is to simply fill the pot half to three fourths full of water, heat the water to a boil, then add the weeds and let them cook. After 15 minutes to a half hour, the weed, including the seeds, should be totally dead.
What is the point? The weeds can be scooped out of the water (so you can cook more weeds) and can be cooled. Once they are no longer hot, go ahead and dump them on the compost pile. The boiling breaks down the cell walls, too, so the weeds compost faster.
When you are completely done, don’t throw away the water. It is full of vitamins and minerals. Just let the water cool down and use it to ‘feed’ your plants. This is good natural fertilizer. For that matter, the cooled water can also be added to the working compost.
I do this with dandelions, wild mustard, wild lettuce, mallow, and crabgrass. Note that all of these is edible and tasty, but my yard and garden is very healthy, meaning that the weeds grow as abundantly as the grass and vegetables. There is frankly too much for us to eat. However, the plants can still be used for the good of the yard and garden.
As a side note, I also feed some of the cooked weeds to our chickens. They particularly relish them.