My eggplants were doing fine until we got a lot of rain and a bit of heat and then kaboom, red spider mites infestation. These tiny little arachnids, the size of a sharp pencil dot, cluster on the underside of leaves and suck the plant juices. In response, the plant develop scar tissues (brown holes and edges), and spends all its energy trying to defend itself. If left unchecked, the plant will die.
There are a few home-remedies to tackle a light infestation.
The quick fix
In a glass jar, mix 1 cup of kitchen oil with ¼ cup of dishwashing liquid – shake well and store for future use. Mix 1 to 2 tablespoon of this mixture in a 1l spray bottle and spray over and under the leaves. This will suffocate the beasts! Repeat every two days until you’re on top of the infestation. I also add seaweed extract to that solution. That gives the plant a boost.
The good practice
Add compost (homemade the better!) or worm castings at the base of the plant (don’t let it touch the stems too much). In healthy compost reside predatory mites that make a feast of red spider mites. This solution is effective when the infestation is at its infancy. Mulch well.
A long term and sustainable solution sit in Integrated Pest Management. Plant insectary plants in and around your veggie patch, such as yarrow, Sweet alyssum, Queen Anne’s Lace. Let your cilantro, parsley and dill go to seeds. The lady beetle adult feeds on nectar from these flowers, and their babies feed on garden pests including aphids and red spider mites.
If the plant is seriously ravaged, pull out, bag and solarise for a few days in the sun. Then compost