The bright orange-red flowers of the marigolds look extremely pretty. At the same time, the plant is extremely easy to care for and thrives in both beds and flower boxes without any problems. But it is not only its appearance that makes the marigold a popular ornamental plant. It is also suitable for ecological nematode and pest control and thus ensures a very good soil environment.
Marigolds are effective against nematodes
Tagetes act like a natural soil treatment
Tiny roundworms, the nematodes, are found almost everywhere in nature. The relatively small, colorless or white worms prefer moist environments. Some species are used successfully as beneficial insects in biological pest control.
Other species, on the other hand, cause massive damage to crops. They react to the infestation with symptoms such as:
- stunted growth
- root rot
- discoloration
- withering
Planting marigolds is an excellent way to combat the tiny pests and permanently improve the soil.
Mode of action of the marigolds
The marigold secretes a scent through its roots that attracts the nematodes. As soon as they suck at the roots or penetrate the root system, the pretty summer flower releases a highly effective toxin that kills the pests.
In order for the marigold to develop its full effect, you should plant marigolds on the affected areas for at least three months, from spring to autumn. For a thorough soil culture, only plant marigolds on the infested soil area. Alternatively, you can plant the marigold between plants and thereby effectively curb the harmful activity of the roundworms.
Marigolds as green manure against nematodes
Some nematode species avoid marigolds because they specialize in weeds and weeds as host plants. In this case, enrich the green manure with marigolds and apply a layer of mulch that is not too thin in the bed. This effectively suppresses the host plants and the nematodes die off as a result. Remove regrowing wild herbs consistently so that the roundworms are deprived of their food base.
tips
All marigold varieties form an excellent plant community with cabbage. The intense scent of marigolds drives away the pesky whiteflies that commonly infest cabbage plants.