Spring isn’t quite here yet, but the aphids are already showing up! Whether they are green, yellow, black, ashy or mealy, these aphids are biting and sap-sucking insects that draw nutrients from plants, which results in a weakening of the plant. It is true that the plant very rarely dies from an attack by aphids, but these small insects are also vectors of several other pathologies such as viruses for example. In this article, we will give you all the tips and tricks to fight in a natural, organic and effective way against these garden pests.

A colony of green aphids on young shoots!

Effective aphid control should begin as soon as the first insects appear, i.e. around March-April. It is during the development of the first buds that the foundresses appear and lay eggs. After flowering, winged aphids are born and spread all over the plants in the garden and lay eggs in the fall.

Biological control: Insects against Insects !

In nature, there are many insects that can be called anti-aphids. We distinguish the predators, so those who eat aphids, this is the case of the Ladybug (larvae and adults), the Aphidolete (the larvae) or even the lacewings whose larva can swallow up to 500 aphids during of its growth. And there are also parasitic insects whose larvae grow in the aphids to their detriment until they turn them into a kind of “mummies! The law of nature is sometimes cruel, isn’t it?

It is sometimes interesting to release auxiliary insects in the garden or vegetable patch, but be aware that keeping biological corridors in your garden, that is to say grassy strips, or flower meadows, for example, allows the development of insects. agriculture that are the natural enemies of so-called “pest” or pathogenic species. You can also let the spiders make their webs in the garden because the winged aphids get trapped there! And then spiders don’t harm plants (sometimes humans, but that’s another story)!

A ladybug larva eats up to 100 aphids a day!

Cultivation methods: Repellent plants & Trap plants !

There are also many plants that have aphid-repellent properties. Indeed, some plants are reputed to repel aphids, this is particularly the case with marigold, mint, savory, rue officinalis, thyme and wormwood. Another method is to plant nasturtiums in a corner of the garden as a trap plant, because aphids literally love this plant, so you can eliminate a good number of aphids thanks to the sacrifices of your nasturtiums!

Natural and organic treatments against aphids !

If the first two techniques above have not eradicated all the aphids in your garden, you still have a very important choice of natural and organic treatments to use. This is the case of nettle manure, very well known to gardeners, it is a preparation obtained by macerating chopped nettle leaves in water with a proportion of 1 kilo of nettle for 10 liters of ‘water. After dilution (20 times), spray on plants affected by aphids. It is a fairly effective and completely natural treatment. Some gardeners also use a preventative treatment from macerating a mixture of nettle, fern, and lemon balm, which are also reported to be effective. Others, advice to spray water that has macerated 2-3 days with tobacco (50 grams of tobacco for 1 liter of water, then dilute the whole in 10 liters of water). Be careful, however, to respect the dose, because too strong, you will get a herbicide… and that is not the objective sought here! Black soap products are also known to be very effective against aphids. To do this, simply spray lightly soapy water (one tablespoon of black soap per liter of water) on the aphids.

However, the effectiveness of some of these preparations has not yet been scientifically demonstrated. But in any case, the use of all these auxiliaries, these repellent plants and these natural treatments represent a real alternative to chemical products since they are totally respectful of the environment! Do not hesitate to leave us comments on your experiences in the biological fight against aphids!

Lucas Heitz, The Curious Gardener

Landscape gardener and geographer, I am passionate about the plant world and its countless curiosities. Founder of the Alsagarden blog and activist for gardening in harmony with Nature, I am also a French gardener, fervent defender of Heritage varieties.