Lavender is best pruned as soon as it finishes flowering. If it is already autumn, it is better to wait until early spring, as there will be very little new growth before winter.

How hard to prune lavender

• Lavender should be pruned back firmly, especially the dwarf forms such as English lavender (Angustifolia), but do not cut back beyond the green growth. 
• Some types, such as French lavender (Dentata), are less hardy and may not regrow if cut back into the old woody part of the plant. 
• As a general guide, cut back about the top one-third of the plant, pruning to just above healthy leaves.

What to expect long term
Lavenders are relatively short-lived shrubs and can become very woody after four to five years. For best results, grow them in a full sun position in very free-draining soil, and add plenty of Garden Time Compost and Garden Time Chicken and Sheep Pellets when planting.