I have a hydrangea in my garden which has red spider mite (pretty confident). Many of the leaves are brown, disintegrating and there are very small red bugs on the leaf underside as well as webs. I have red the advice on glasshouse red spider mite but still have the following questions:
1) if the female spiders (the red ones) are already active is it too late to save the plant (which looks pretty bad at the moment)? I suspect it may not flower as the flower buds look damaged and brown too.
2) Should I just get rid of it to stop the mite spreading to the cosmos and salvia that are next to it (only put them in recently)?
3) If I can save it and should treat it, I am not keen to use chemicals. The RHS website recommends "plant oils or extracts (e.g. Vitax Organic 2 in 1 Pest and Disease Control, Bug Clear for Fruit & Veg) or fatty acids (e.g. Bayer Organic Pest Free, Doff Greenfly and Blackfly Killer, Bayer Natria Bug Control) or urea/mineral lattice (SB Plant Invigorator), which can be used to keep mite numbers down before it is time to introduce the predator." Any advice on where to get these//what is best/what to do with them/if I have to introduce a predator too?!?!
Thank you. I am a new but keen gardener and have never treated pests on plants before.