I grow many plants indoors in a conservatory - not only vegetables for food like tomatoes, but also many perennials, tree seedlings, collection of cactus, etc. I live in an arctic climate, only 3 months frost-free, so growing indoors is essential.
The mites seem to be killing always the same prone species (like moringa, beans, seedlings of honeylocust, amaranth, etc) It's not a problem for many plants, it's a manageable problem for many species (like many tree seedlings, corn or tomatoes), but it is a deadly risk for some species like those. I keep overwintering some perennials indoors, and since the conservatory with artificial lights and pots is an artificial environment, some pests get out of control.
I tried everything against spider mites, but nothing works. Predator mites definitively do not work. Cleaning everything definitively does not work. Introducing pest repelling plants like catnip, does not deter the mites too. Tried neem, essential oils, and did not work. I am tired of reading articles on spider mites and solutions that do not work.
So, I want to know, how can I, from the Permaculture point of view, create a healthy and balanced environment with my indoor plants. I already have a lot of diversity indoors but the mites kill always the same sensitive species, those species always die to mites even if I give them the best of conditions. Plants first became speckled, then leaves dried, and then eventually defoliated plants are so much weak that die.
Any bright ideas?
in Portugal, sheltered terraces facing eastwards, high water table, uphill original forest of pines, oaks and chestnuts. 2000m2
in Iceland: converted flat lawn, compacted poor soil, cold, windy, humid climate, cold, short summer. 50m2
I have successfully cleared red spider mites by drastically increasing humidity. They like it dry, and can't live where it's wet. This might not be achievable if you have a really big space, but I got them off my orchids by keeping trays of gravel and water under the pots, and using a mister to spray water on obvious infestations.