Leaves that curl, turn sticky and sometimes blacken like soot signal aphids (Aphidina), sap-feeding insects that swarm on rose trees, fruit trees and flower buds. The weakest plants suffer most, so combining ladybugs, repellent plants and organic sprays, rather than chemicals, keeps colonies down and leaves the garden’s natural defences intact.
Leaves curl up and become sticky.
| Name | Aphidina |
|---|---|
| Common name | aphid |
| Appears in | spring, summer, fall |
| Favorable conditions | most plants might be attacked, but the weakest plants are the most vulnerable |
Having a garden brimming with insects, especially ladybugs, greatly helps control aphid populations.
Regular treatments against aphids will help you consistently eliminate them and keep them away from your plants and rose trees.
Aphids attack many plants, rose trees and fruit trees in our gardens. They can do considerable damage.
The following treatments can help fight aphids, and if one particular strategy doesn’t seem to work, you can apply several solutions together. Associating repellent plants and, beneficial insects and organic treatments is most effective.
Special flowered lawn mixes are prepared these days, which repel most parasites and specifically aphids when the combination of flowers start to bloom.
Finally, a basic rule is to reduce use of chemical products as much as possible.
They usually wreck havoc in the local ecosystem, and weaken natural defenses that usually make plants immune to diseases and parasites.
Each of the organic solutions described above works in a different way, and several can be combined when a single one is not enough. Here is what each method does and what to keep in mind before using it.
| Method | Type | How it acts on aphids | Good to know |
|---|---|---|---|
| Ladybugs and other predators | Beneficial insects | Ladybugs eat aphid larvae; green lacewing and hoverfly also devour aphids | Practised by professionals managing parks, and 100% organic |
| Fermented stinging nettle or fern tea | Organic spray | Fights aphids on treated plants | Sold in horticulture stores or produced at home |
| Fermented rhubarb tea | Organic spray | Home-made preparation used against aphids | Can be prepared as early as mid-spring with fresh rhubarb leaves |
| Soapy water | Organic spray | Makes it hard for aphids to stick to leaves | Marseille or beldi soap, 5 oz in 1 quart water plus a tablespoon of oil |
| Repellent and trap plants | Companion planting | Nasturtiums trap aphids, French marigold and lavender repel them | Helps control populations naturally, French lavender works too |
| Fighting ants | Indirect control | Removes the ants that attract aphids and fuel their spread | Necessary once ants have established their nest |
| Aphidoletes larvae | Beneficial insects | Excellent aphid predators | Only active from 60°F (16°C) and rarely sold in horticulture stores |
| Pyrethrum | Plant-derived treatment | Very effective, annihilates the parasites | Main ingredient of many aphid-control products, usable in organic farming |
| Flowered lawn mix | Preventive sowing | Repels most parasites, aphids especially, once the flowers bloom | Can be sown in gardens and in the vegetable patch |
Combining beneficial insects, repellent plants and an organic spray is more effective than relying on a single method.
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Most damage occurs during the growth or vegetation phase, specifically in spring and at the beginning of summer. This is when treatments are most needed and effective.
