How to use them in a targeted manner

Tagetes act like a natural soil cure

Tiny roundworms, the nematodes, occur practically everywhere in nature. The relatively small, colorless or white worms prefer moist environments. Some species are successfully used as beneficial insects in biological pest control.

Other species, on the other hand, cause massive damage to crops. These react to the infestation with symptoms such as:

• Stunted stature
• Root rot
• Discoloration
• Withering

Planting marigolds is an excellent way of combating the tiny pests and improving the soil over the long term.

How the marigolds work

The marigold secretes a fragrance through its roots that attracts the nematodes. As soon as these suck on the roots or penetrate the root system, the pretty summer flower releases a highly effective toxin that kills the pests.

So that the marigold can develop its full effect, you should leave the infested areas for at least three months, from spring to autumn,

plant marigolds. For a thorough soil culture, plant only on the infested ground area Tagetes. Alternatively, you can plant the marigold between plants and thereby effectively curb the harmful growth of the roundworms.

Marigolds as green manure against nematodes

Some roundworm species avoid Tagetes because they specialize in weeds and weeds as host plants. In this case, enrich the green manure with marigold and apply a layer of mulch that is not too thin in the bed. This effectively suppresses the host plants and the nematodes die as a result. Consistently remove regrowing wild herbs so that the nematodes are deprived of their nutritional basis.