Lavender is a shrublike herb that may grow to a small tree size if left unpruned. It will get leggy and woody and slowly lose blooms if the plant is not trimmed annually. Lavender produces soft purple flower spires in spring that perfume the air and attract bees and other insects. Plants like lavender should not be pruned in the cooler seasons because the cuts spur new growth that can be damaged or killed by sudden cold weather.
Lavender is a native of Mediterranean zones and thrives where conditions are sunny but soils are inhospitable. Rocky, sandy and low-fertility soils are suitable sites for lavender. It is simple to grow and may grow to up to 2 feet or more when mature. Lavender has multiple branches that rise vertically from a central crown. The leaves are small, narrow and greyish green. The plant has woody stems with scaly, sloughing bark. Lavender is perfect for the xeriscape garden or hot, sunny neglected areas of the landscape.
Prune lavender in very early spring. However, some gardeners prefer to prune it in fall so it is ready for new growth in spring. This can be an issue in areas that experience freezing temperatures and contribute to dieback of new growth. Similarly, pruning in spring could result in removal of new growth and flower buds if done too late in the season. Pruning perennials is always dicey due to timing. It is best to know your climate so you can make an informed decision as to when to trim your lavender. Overall, try to prune spring-blooming plants like lavender when the first green buds appear. You may also cut back the spent blooms, or deadhead, after the plant has finished flowering.
Don't cut lavender back to the ground. The woody stems will not resprout and you will be left with a clump of scaly wood. Lavender produces new growth off the tips of the previous seasons growth so you don't want to remove all the greenery or you will be left with a stump. Remove up to one third of the lavender's green growth. After the plant has bloomed, shape it by removing the flowers back three to five leaf nodes below the stem. Post-bloom is when you should shape the plant and get it back to a size that is manageable. This gives it the entire summer to re-form and produce new growth. The new growth will have time to harden off before winter, sparing the plant damage.
Lavender is used as an aromatic, tea and seasoning. You can cut lavender flowers for harvest in early summer just as the flowers are opening. Morning is the best time to harvest lavender to avoid the bees that mob these plants. Cut each individual flower stem off just above a leaf node. This will prevent ugly dried-up stems peppering your plant. Areas with long growing seasons may be able to get a second bloom off the plant after removing the flowers. Dry the flowers by hanging or use them fresh.