Co-Authored By:
Marigolds are often used as a natural nematode deterrent in the garden. If marigolds actively produce these toxins in the compost pile, your actively decaying mound would not break down correctly. As a result, rot and an offensive odor may take over, rendering your compost useless as a healthy organic material.
Likewise, can flowers be composted?
Yes, like most plants, flowers can be used as a composting ingredient. Flowers would be considered a green composting material (source of nitrogen). Dried-up flowers would be considered a brown compost material. Please note that you should avoid using any flowers that died due to some sort of plant disease.
Also asked, can you put dead plants in compost?
Even if shredded, they have a very high carbon content for a compost bin. A good GREEN source, weeds, plant trimmings, dead flowers, stalks, etc. are excellent materials. When placed in bin, take a shovel and slice or chop them up into smaller sizes for faster decomposing.
Marigolds do not draw nematodes away from crop plants. They are simply one of the possible hosts. Digging the marigolds in is good for the soil, but it does little to help the nematode problem. The natural nematicides are only found in living plant tissue.