Eggs that are laid may still be there, so repeat washing will prevent the populations from building up again. Watch all your evergreens and certain garden plants for spider mites this summer. Damage is identified by yellowish to rust color of evergreen foliage. Presence of mites can be detected by tapping branches over a white piece of paper. Numerous small specks should be noticed crawling on the paper if you have spider mites.
First injury is normally near buildings or in warmer locations.
Dry, warm weather hastens development. Spraying twice with a miticide 10 days apart will stop spider mites. A jet spray of water will also flush them to the ground. Dig a large two foot square hole, fill it up with soil, compost or half a bag of old manure plus a cup of bonemeal. Give it a rose fertilizer as per instructions on the package and keep it well watered the first summer so the roots never dry out.