Discover what you need to know for pruning lavender successfully. While lavender is tough-as-nails in the right growing conditions, it does need special attention when it comes to pruning. As a matter of fact, pruning lavender plants correctly can help yield more flowers and a healthier, longer-lived plant.
In botanical circles, lavender is known as a semi-shrub. Understanding this concept forms the foundation for proper lavender pruning. A semi-shrub is a plant that grows like a perennial, producing green growth each year. The older parts of stems on a semi-shrub start turning to wood after a few growing seasons. On any type of lavender, you’ll find that deep inside the pretty mound of grey-green leaves, stem bases are woody.
Those woody stems—in a lavender plant—are not good news. That wood is weak, not strong like a tree trunk, and when winter brings snow or ice, the woody stems are more likely to break. Lavender’s woody stems don’t produce new green growth, so as stem tissue shifts to wood, your plant is losing the ability to produce additional green shoots, which are the ones that flower. While pruning lavender, if you cut into woody stems, they won’t grow again, but simply die.
When you’re pruning lavender plants, you’re aiming to slow down the plant’s progress toward forming woody stems. In general, you need to plan on pruning lavender at planting time and every year right after it flowers. When planting lavender, prune plants lightly, removing all growing tips. This encourages the plant to branch. Use this same technique every year as new growth starts to appear.
Pruning lavender after flowering is ideal, but if you miss the window, don’t fret. You can slot your lavender pruning when it works for you, as long as you complete it by early spring. Lavender flowers on the new growth that appears each year, so if you prune before new growth really starts lengthening, you won’t interfere with blossom formation.
Pruning lavender in spring is also sometimes necessary in coldest regions to remove stems that suffer winter damage. Pruning lavender in late summer to fall helps open the plant’s interior to allow good air circulation and also removes some of the branches, which can ultimately help prevent winter damage. Ideally, pruning lavender in spring and fall is a great idea, if you can squeeze that into your garden chore schedule.
When you’re pruning lavender plants that are established, aim to remove at least one-third of all growth. With older plants, you can cut back to a point that’s three leaf pairs above the woody stem area. Don’t cut into the woody area, because the buds on those stems won’t sprout.
Original article and pictures take http://www.hgtv.com/outdoors/flowers-and-plants/herbs/pruning-lavender-plants site