Lavender

English lavender is a Mediterranean shrub from the dry stony hillsides of southern Europe, and every single thing it wants follows from that. Sun, sharp drainage, poor soil, moving air, and nothing whatsoever in the way of kindness. It is not a difficult plant, but it is killed reliably by the two things gardeners most want to do for it, which are to feed it and to keep it moist. It is also the first outdoor plant in this journal, and a good demonstration that “hardy” and “easy” are not the same word.

Light

Full sun, six hours a day or more. In shade it grows soft and open, flowers thinly, holds moisture around its base and rots over its first wet winter.

It is not a houseplant. It is sold as one, and it survives a windowsill for a few months before declining, because it needs direct sun, air movement and a genuine cold rest that no living room provides. If you want lavender by a door, put the pot outside the door.

Soil and drainage

This is the whole game. Lavender needs free draining ground and will grow happily in soil most plants would call poor: sandy, gritty, chalky, thin. In heavy clay it lives for a season or two and then dies at the base over winter, and the cause is wet roots rather than frost. English lavender takes hard frost without complaint.

If the ground is heavy, plant on a slight mound, dig a generous handful of grit into the hole, and mulch with gravel rather than bark or compost, which hold water against the stems. In a pot, use a gritty mix, a terracotta pot and no saucer.

Water and feed

Water a new plant through its first summer while it roots out, and after that, in the ground, almost never. An established lavender in a temperate garden needs no watering at all. In a pot, soak it and then let it dry right out, about every ten days in summer and once a month in winter.

Do not feed it. Feed gives soft green growth, fewer flowers and noticeably less scent, and makes the plant more likely to rot.

Pruning, which is not optional

Lavender does not regenerate from old bare wood. That single fact governs everything about pruning it. Cut it every year, straight after flowering, taking off the spent stems and about a third of the current year’s growth, and shape it into a dome. Never cut back into the leafless grey wood at the base, because nothing will come from it.

A plant pruned this way every year stays compact and productive for eight or ten years. A plant left alone for three or four years becomes a woody sprawl with a bare centre, and at that point it cannot be rescued; the only cure is to take cuttings and replace it.

Sowing, planting and harvest

Sow in spring, March to May in the northern hemisphere and August to October in the southern, at about 18 degrees, and expect seed raised plants to vary. Cuttings are the better method and give you the same plant: take semi-ripe cuttings in late summer, strip the lower leaves, and root them in gritty compost.

Harvest the flowers as the first few on each spike open, which is June to August in the north and November to January in the south. Cut on a dry morning and hang the bunches upside down somewhere airy and dark.

Ailments

A soft brown base is wet roots and is the usual cause of death. Leggy growth is shade or years without pruning. No flowers means shade, feed, or a plant cut too hard into old wood. The ledger below has the rest, and almost all of it comes back to drainage.