Flowers for the cottage garden and herbs enchant with their lush blooms. But they also attract insects to the garden as pollinators, protect fruit and vegetables from pest infestation and thus safeguard the harvest. In other words, they are blooming plant protection.
It is not enough to grow vegetables with care. One has the duty to arrange it according to its colors and frame it with flowers. The instruction for the design of a monastery garden from the 15th century is as relevant today as it was then.
Agricultural scientists have now demonstrated that so-called flower strips next to wheat fields not only delight walkers, but also significantly increase yields. With its pollen and nectar, the colorful border provides food for ladybugs, predatory wasps and many other beneficial insects. Pests, on the other hand, are hardly to be found in the vicinity of the natural strips. If you take advantage of this effect when growing fruit and vegetables, you can largely dispense with other plant protection measures.
Summer flowers from the daisy family, such as annual blanketflower (Gaillardia pulchella) and coneflower (Rudbeckia), are true revitalizers for the soil. The fast-growing plants cover the surface like a carpet in a short time and leave even stubborn weeds such as goutweed, creeping buttercup and gallant soldier little chance. Tagetes, zinnias, and marigolds can do even more: they attract stem and root lice that persist in the soil and kill them as soon as they penetrate their roots.
The symptoms of damage to vegetable plants are often mistaken for nutrient deficiencies, because the culprits are not visible to the naked eye. The foliage of carrots suddenly wilts and the roots become leggy, the tips of onion shoots turn brown, and potatoes and tomatoes start to deteriorate. If you suspect it, you should not puzzle around for long, but put an end to the spook by sowing a particularly effective seed mixture of several defensive plants.
How to attract beneficial insects?
Umbelliferous herbs such as dill and coriander indirectly prove to be a pest deterrent. The flowering herbs attract countless hoverflies. For the offspring of these harmless flying artists, the aphid colonies on young bean or pea shoots are a veritable feast. During development, a single larva eats up to 700 of the annoying aphids.
Nasturtium is universally applicable. As ground cover on the tree discs of fruit trees, it drives blood lice away and chases whiteflies out of the greenhouse. In the vegetable patch, the plants develop a great attraction to the cabbage white butterfly. The female butterflies are fooled by the strong mustard oil smell and lay their eggs on the cress leaves. This is how you ensure the survival of the beautiful butterfly without having to worry about caterpillar feeding and unappetizing excrement nodules on savoy cabbage and kale.
What natural enemies do pests have?
Encouraging predators is the best strategy for sending pests packing in semi-natural gardens. Ichneumon wasps feed on nectar and other sweet plant juices. Their offspring prefer protein-rich foods, such as aphids, fruit flies or other insect pests. The wasp places its eggs directly into the animal food source with a long laying stinger. Within a few days, new wasps develop from the well-fed larvae. What remains is the empty shell of the host.
Ladybugs and their larvae can not only destroy entire aphid colonies in a short time, scientists have discovered that the beetles even scare their prey. At the sight of them, the aphids emit scents with which they warn their conspecifics. The more of them there are in the air, the faster the pests start to retreat.
Flowering bed neighbors for fruits and vegetables
- Catchfly (Silene viscaria) increases the resistance of all bed neighbors, especially bush and pole beans. The extract obtained from the seeds contains plant hormones that promote root growth.
- Cornflower (Centaurea cyanus) attracts gall wasps and other natural enemies of cabbage white butterfly and cabbage moth. Particularly effective in seed mixtures for flowering strips, together with buckwheat and forage vetch.
- Forget-me-not (Myosotis sylvatica) repels raspberry beetles and strawberry blossom weevil. Plant in the spring as a border for the strawberry bed and extensively on the raspberry ridges.
- Lavender (Lavandula angustifolia); ants, aphids, earth fleas and bugs in the long term avoid the vicinity of the bushes hybrid cultivars. (ornamental lavender) contain less essential oils, therefore the repellent effect is weaker
- Marigold (Calendula officinalis) decimates root aphids and nematodes, drives away potato beetles and cabbage whitefly. Use only unfilled varieties and selections as nectar and pollen donors for beneficial insects.
- Nasturtium (Tropaeolum majus) repels aphids on fruit trees and whiteflies. Catch plant for bean aphids and cabbage whiteflies, suppresses root weeds such as goutweed. Sow in May on the tree disk or the edge of the bed. In the vegetable garden, e.g. as a companion planting to tuberous fennel and celery, choose non-ranking varieties.
- Yarrow (Achillea millefolium) attracts ladybugs and promotes growth and resistance of all vegetables. Increases the content of essential oils in medicinal and aromatic herbs, e.g. sage, mint and thyme.
- Zinnia (Zinnia angustifolia and Z. elegans) destroys harmful nematodes and is considered a butterfly magnet. Pre-cultivation in pots from March, direct sowing between the vegetable rows at the earliest in early May, as a nectar supplier preferably sow unfilled varieties.