Trim and tidy these fragrant woody perennials as soon as the bees lose interest, says Sally Coates from Norfolk Lavender
Pruning lavender helps plants to keep their neat, rounded shape and prolong their lifespan. At Norfolk Lavender, head gardener Sally Coates prunes the National Plant Collection of Lavenders with shears.
“If left unpruned, plants become too tall, woody and gappy, splay open and finally collapse,” she explains. “For plant health and longevity, it’s best to maintain a compact, rounded shape, or for a lavender hedge, a nice undulating ‘caterpillar’.
“Pruning also promotes more vigorous growth the following year and can help to keep stems from becoming congested.
“With a young but established plant, cut the stems right back after flowering at the end of summer. This way the new shoots emerge from low down on the base of the plant next spring.
“Established lavender plants that have some woodier growth at the bottom are generally tidied and maintained with just one annual cut, straight after flowering in late August/September, once the bees are no longer interested. If the flowers have gone over and look dull, they’re developing into seedheads. You can cut these back as soon as they form, using secateurs, or wait until October.
“At Norfolk Lavender, we give another light prune in early spring, mid-March. This tidies up ‘loose ends’ and gets them back into shape. After pruning, we apply a mulch of well-rotted organic matter to give them a boost and hold back weeds.”
Sally uses lightweight wavy-edge Fiskars shears for maintenance pruning, removing the spent flower stems and trimming the plant into a neat ball. She’ll use her Felco no2 secateurs for the more precise job of renovating a plant that’s grown too tall and woody.
“You may need to completely regenerate older, established specimens by cutting back into the old wood to remove the congested stems, allowing light and air into the centre.
“It’s true that lavender doesn’t regenerate if you cut hard back like this, but you can often find signs of young shoots sprouting from those lower, woody stems. This is a good indication that hard pruning could help to regenerate the plant.
“The example we’re using below is Lavandula intermedia ‘Eidelweiss’ – it’s woody but there’s a lot of new growth in there. This shows you can cut right into the old wood, remove tatty older branches and encourage younger shoots to grow.”
Sally Coates has been a gardener at Norfolk Lavender for three years. For tours, visits and shopping see www.norfolklavender.co.uk
Plant name: Lavandula angustifolia (English lavender) and Lavandula intermedia (lavandin)
Plant type: Woody perennial; subshrub
Why prune? To harvest stems; keep bushes looking neat and hedges dense and uniform; encourage vigorous growth next spring
When to prune? Late August-September and tidy up in spring. Plants that can be pruned like this: Lavandula angustifolia; Lavandula intermedia; Hebe pinguifolia; Hebe speciosa; and all their cultivars
Pruning tools: Shears, secateurs
1 READ THE PLANT This woody lavender has gaps and splayed areas, so it’s a good candidate for renovation pruning. Small shoots emerging from the woody base indicate that stems should regenerate.
2 CUT OUT OLD GROWTH Carefully cut out the old growth above the young shoots to open up the middle of the plant. Use sharp secateurs to cut as close as you can to the new growth without harming it.
3 KNOW WHEN TO STOP Continue until all the woody growth has been removed and you’re left with a neat stump of cut stems bearing new shoots. Apply a mulch of well-rotted organic matter around the plant.