Water in the morning and evening, trying to avoid wasting too much water on leaves. Using a soak hose ensures water is deposited next to the roots.
Cut back perennials that have finished flowering to help them recover from the drought.
Cut back Lavender leaving at least 2 pairs of leaves below the point you cut.
Sow winter lettuce, mustards and rocket for harvest in autumn and next spring.
Deadhead Buddleia to encourage more flowers into the autumn which will provide important food for butterflies.