This method is used to reduce the size of a plant, create a hedge or to renew old overgrown plants. Renew overgrown plants by cutting them back to within 6 to 12 inches of ground level. This practice results in abundant new growth by midsummer. The best time to renew azaleas is before spring growth begins. This allows sufficient time for next year s flower buds to form in midsummer, and for new growth to mature and harden off for winter.
Renewal pruning before spring growth, of course, means that flowers are sacrificed for that year.
After renewal pruning, prune the tips of new shoots when they are 6 to 12 inches long, to encourage branching and a full canopy. Thin out new shoots emerging from the old stem. Keep the soil moist during the period after severe pruning. The most common diseases on azaleas in South Carolina include petal blight, leaf gall, leaf spots, dieback, and root and crown rot. The most common insects are lacebug and spider mites.