Aphids are soft-bodied bugs that suck sap from young fleshy plants. They appear very small and pear-shaped with the young having a pink cast while some are lime green making it difficult to spot them on the stems.
They carry with them viruses that they transfer to the plant as they feed. What’s more, they secrete honeydew that creates a conducive environment for sooty molds to thrive in, which may cover the leaves of a plant which in turn deprives the plant of sunlight.
Preventing aphids' infestation before they start is obviously the best option, but they can still be eliminated once discovered. Here are a few ways on how to how to organically control Aphid pests:
1. Physical removal
At the initial stages of infestation, the best way to control them is to physically remove the insects from the plant. You need a pair of gloves and then you need to pinch or brush the Aphids carefully from the leaves and stems. Where the infestation is on few branches or stalks, it could be best to prune the affected portions and put them into a container with filled with soapy water to kill the insects.
2. Neem oil
Neem oil may be added to water and sprayed onto the affected plants. The oil contains certain chemicals that act as repellents to the aphids' as well as other garden pests such as caterpillars and ants. Additionally, neem oil is used to control certain types of fungus that infect plants in your greenhouse kit.
3. Beneficial insects
At times, it may be more effective to introduce predator insects to the areas of the greenhouse infested with aphids. The most commonly used insects are ladybugs and ladybirds which can be purchased in bulk or naturally drawn into your greenhouse. You may get them in quantities of 150, 300, 1500, 4500, and 18,000.
Other predators that are known to eat aphids are green lacewing and hoverfly larvae. Naturally drawing beneficial insects into your greenhouse can easily be done by planting fragrant herbs including catnip, garlic, and oregano that attract these predators. Also, try growing herbs like mint, fennel, dill and clover around your garden to naturally attract lacewings and ladybugs
A hose can offer a strong spray of water that will knock aphids off the plant. Additionally, it will remove any honeydew left behind by the pests so that they won’t be able to return. You need enough water to spray the plant every day until the plants are aphids’ free.
Note: Do not do this to young plants as you can damage them this way.
5. Reflective Mulch
Putting reflective mulch just beneath the plant can deter aphids. Reflective mulch is an effective yet easy way to control most pests that hide in the dark spots.
With this many organic options, chemical insecticides should never be your first choice, but as a last resort when organic methods fail to tackle the aphid problem.