Cultivate beautiful gardens - counteract harmful nematodes

If you pick up a handful of soil, you probably have a load of nematodes, small roundworms that are almost invisible, in your hand. There are approximately one million species, and about 28,000 of them have been given their own names so far. Trichinella, roundworms, and tapeworms are all examples of nematodes. These can make us sick, but others can be used for good – for example, to fight against slugs. So there are good and less good nematodes. In the soil, most of them live on bacteria, many of them benefit by eating pests. but some of them can harm plants and plant roots.

Root-knot nematodes are perhaps the nematodes that growers fear the most. These small roundworms penetrate the roots of plants and cause damage that prevents the plant from developing as it should. Plants attacked by root-knot nematodes are more susceptible to drought and cold, and the harvest is poorer. Sometimes the damage is worsened as fungi and bacteria penetrate the root lesions. Our beloved roses are especially sensitive to this, but strawberries, carrots, onions, potatoes, raspberries, blackberries, and corn are also affected.

Sometimes it can be difficult to see if a plant is affected by root nematodes, since lack of water, nutrients, and other pests can also make a plant look a bit unhealthy. However, sometimes it is possible to spot galls, that the root system has become matted together, or distorted wilted plant parts.

The roots of a tomato plant that has been attacked by nematodes., Root nematodes can survive in the soil for several years and overwinter in all stages. They spread further with old plant material and can occur in all types of soil, although they are most commonly found in clay soil.

If you replace the soil, the problems with root-knot nematodes and soil fatigue disappear, but if the area is large it can feel like an impossible task. Adding organic material that promotes microorganisms is also an alternative, it strengthens the plants. But perhaps the easiest is to sow marigolds (Tagetes) - preferably Tagetes Patula, which releases many substances that nematodes cannot tolerate. Marigolds are very suitable for companion planting and they come in many colors, such as yellow, orange, light yellow, white, and raspberry pink. Substances released from living marigold roots are said to not only deter root-knot nematodes, but also certain pests. It has even been claimed that the substance can have an effect on bedbugs.

All types of marigolds are easy to grow and maintain, they often withstand wind, strong sun, and shade. Their worst enemy is perhaps slugs, but if these are kept away, these beautiful flowers will bloom willingly all summer - whether planted in pots, in the open ground, or in flower beds. By pre-cultivating marigolds, or buying ready-made plants, you give them an advantage over the slugs - who often target delicate and fresh young plants. Marigolds Patula usually grow to be 20-25 cm high and have a compact growth habit. If you pinch off the first flowers, they will become larger and bushier.

Make companion plantings with marigolds, preferably different types of Tagetes Patula.Only plant seedlings that look healthy.Clean tools that have been used in different soil.Practice crop rotation, avoid growing the same plant in the same spot year after year.Grow nematode resistant plants. You can also vary between susceptible and resistant plants from year to year.Add organic material, such as compost and/or bokashi, to enhance soil balance.