I have a hibiscus that came indoors for the winter and became infested with white flies. I prefer organic measures but broke down and sprayed it with Safers End All which DID NOT help in the slightest, despite constant application. The Hibiscus has now gone outside and the bugs have dispersed, but I am still concerned. I have read that worm castings are the answer. But I have called two garden centres and they don’t supply. I’d like an organic solution if possible. The hibiscus now resides on my downtown Toronto rooftop container garden with organically grown tomatoes and leafy greens potted with homegrown compost
White flies are a common occurrence when bringing plants indoors to overwinter.
Safers End All is an insecticidal soap that works, in many cases, at controlling white flies, aphids, spider mites and spittle bugs. Another alternative you may wish to try in the future is Diatomaceous Earth which is a natural clay based granular powder that is very effective at killing a wide range of bugs and is indoor and pet friendly.
In the fall, before you bring your Hibiscus indoors again, give it a good hardy spray with water from a hose to wash off any pests that may be lurking. Take note of the soil and check for any insect activity there too. If anything is found on the soil surface, spray it with an insecticidal soap.
Worm castings will help your plants grow well but won’t solve your bug issues directly. Worm castings have been found in some studies to be superior to compost, but are not as widely available and can be expensive. In Toronto, compost would be a good option for an organic soil amendment and is readily available free from the city or through garden centres and more often from big box stores.