Planting and pruning lavender: when, where, how much to cut

Which lavender to choose?

English lavender is the hardiest and the most fragrant. Its best-known cultivar, 'Hidcote', is low, compact and dark violet; it is the best for edging and low hedges. Lavandin is larger and longer-stemmed, flowers later and smells stronger; most lavender fields in Provence are lavandin.

French or Spanish lavender (Lavandula stoechas) is known by the purple bracts like little ears on top of its spikes. It is lovely, but does not survive our winters in the garden: keep it in a pot and move it somewhere frost-free for winter. The silver lavender is also only for mild-winter areas.

English lavender

Evergreen

toxic

Height

30–90 cm

Hardiness

down to -29 °C

Planting distance

40 cm apart

In a hedge

3 plants per metre

Price per plant

€5.90

English lavender 'Hidcote'

Evergreen

toxic

Height

30–60 cm

Hardiness

down to -29 °C

Planting distance

35 cm apart

In a hedge

3 plants per metre

Price per plant

€5.10

Lavandin

Evergreen

Height

0.6–1 m

Hardiness

down to -23 °C

Planting distance

70 cm apart

In a hedge

2.5 plants per metre

Price per plant

€9.10

Lavender	Height	Hardiness	Planting distance	In a hedge	Price per plant
English lavender Evergreen toxic	30–90 cm	down to -29 °C	40 cm apart	3 plants per metre	€5.90
English lavender 'Hidcote' Evergreen toxic	30–60 cm	down to -29 °C	35 cm apart	3 plants per metre	€5.10
Lavandin Evergreen	0.6–1 m	down to -23 °C	70 cm apart	2.5 plants per metre	€9.10

The table shows the lavenders sold in your country. The planting distance is for a free-standing group; in a hedge they go closer. The price is the typical price of a plant of the usual size. The ASPCA lists lavender as toxic to dogs and cats; symptoms usually come only from eating a larger amount.

Where to plant?

• In full sun: it needs at least six hours of sunshine a day. In part shade it gets leggy, flops and hardly flowers.
• In loose, free-draining soil. It is not the cold that kills lavender but winter wet: in wet, heavy soil its roots rot. On heavy clay, plant it on a mound or ridge 20-30 cm high, in a raised bed or on a bank, and mix coarse sand and fine gravel into the soil.
• Limy soil suits it, which is why it does so well in most gardens of the region. Do not add manure or much compost: in rich soil it gets leggy, falls apart and smells less.
• Do not plant it next to a watered lawn, hydrangea or other thirsty plants; the watering is too much for it. Mediterranean companions suit it: sage, yarrow, blue fescue, stonecrop.

Planting

• The best time is spring, from April to May, once the soil has warmed. That way the whole summer goes into rooting, and it goes into winter strong. In autumn, plant only until early September and only in loose, sandy soil: in cold, wet soil a young plant easily rots.
• Set the plant as deep as it was in the pot, no deeper. In a free-standing group, space plants about 35-70 cm apart, as in the table.
• Mulch its base with fine gravel instead of bark: gravel keeps the neck dry, bark mulch keeps it damp.
• Water it regularly in its first summer if the weather is dry. Once established, lavender needs watering only in a long drought.

Pruning: when and how much

Prune lavender twice a year. The main cut comes in spring, in late March or April, once hard frosts are over: cut the shoots back by about two thirds, but always leave green, leafy growth on each stub. This keeps the bush compact, brings plenty of new flowering shoots and delays it going bare. Shoot tips caught by the winter come off at the same time.

After flowering, in late July or August, cut off the faded flower stalks and with them the top 2-3 centimetres of leaves, keeping the bush a nice dome. Do not prune from September on: the new growth would not ripen before winter and could freeze.

• Never cut into the bare, woody part. Lavender does not regrow from old, leafless wood: what is left there stays a bare stick.
• Prune young plants in their first two years too, so they branch from the base and stay compact. Left to grow, they soon go bare and flop.
• An old plant that has flopped and gone woody at the base cannot be rejuvenated by pruning. After 10-15 years it is worth replacing.
• Prune French lavender gently after flowering, only the flower stalks and shoot tips, as it regrows from wood even less.

A lavender hedge

For a low, fragrant hedge or path edging, 'Hidcote' is the best: planted 30-40 cm apart, 3 plants a metre, it closes in two or three summers. Larger lavandin goes 45 cm apart, 2-2.5 plants a metre. A 10-metre 'Hidcote' hedge thus takes about 30 plants.

Prune a hedge like a single bush: harder in spring, lightly after flowering, in one go, with a rounded top. The hedge planting guide also works out the numbers and price for your own length, and you find plants for low hedges in the low hedge plants list.

Winter

• English lavender and 'Hidcote' survive to about -25 °C in the garden without cover, if the soil drains freely. Lavandin is more tender: it overwinters in milder areas in a dry, sheltered spot, but in a cold winter, or in heavy or wet soil, it can be killed.
• Do not cover it for winter with leaves or mulch: underneath it stays damp and the plant rots. Gravel is fine.
• The roots of a potted lavender freeze and rot far more easily than in the ground. In winter stand it by the house wall, out of the rain, and water only sparingly.

Harvesting and drying

For drying, cut lavender when the lower flowers of the spike have opened and the upper ones are still in bud: that is when it smells strongest. Cut on a dry, sunny morning once the dew has dried.

Tie the stems in small bunches and dry them upside down in a dark, airy place for a week or two. Whatever you did not pick comes off with the pruning after flowering.