Repotting guide

When & how to repot French Lavender (Lavandula dentata)

Also called Fringed Lavender.

More about french lavender

About French Lavender

Lavandula dentata · also called Fringed Lavender · herb

French (fringed) lavender has distinctive toothed grey-green leaves, a soft balsamic-camphor scent, and pale lavender flower spikes topped by small bracts, blooming over a very long season. It is more tender than English lavender, needing full sun, sharp drainage, and frost protection in cold climates, where it is best grown in pots and overwintered under cover.

Mature size: Around 60-90 cm tall and 60-90 cm wide, larger in frost-free conditions.

Watch for — Frost damage: Less hardy than English lavender, it is killed or set back by hard frost; grow in containers that can be moved into a frost-free, bright spot for winter.

How to tell french lavender needs repotting

Repotting on a calendar is less reliable than reading the plant. For french lavender, watch for these signs:

Roots growing out of the drainage holes, or the rootball lifting the plant proud of the rim.
Soil that has shrunk away from the pot sides and no longer holds water.
The pot is unstable because the plant has grown top-heavy.
Old, compacted, broken-down mix that stays wet too long — for a succulent that is a rot risk, so refresh it even if the pot size is fine.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot french lavender

Every 2–3 years, into bone-dry mix. French Lavender's growth habit — bushy, woody-based evergreen subshrub with an almost continuous flowering season in mild climates; faster-growing and softer-stemmed than english lavender. — sets the pace. French (fringed) lavender has distinctive toothed grey-green leaves, a soft balsamic-camphor scent, and pale lavender flower spikes topped by small bracts, blooming over a very long season. It is more tender than English lavender, needing full sun, sharp drainage, and frost protection in cold climates, where it is best grown in pots and overwintered under cover.

What size pot to step french lavender up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. French Lavender stores water and rots in a large pot of slow-drying soil. A tight terracotta pot that dries fast is far safer than a generous plastic one. Never up-pot a succulent by several sizes.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot french lavender

Spring or summer, while french lavender is in active growth and warm, is best — roots recover fastest then, and the plant is not sitting in cool damp soil. Avoid repotting a succulent in winter dormancy.

Step-by-step: repotting french lavender

Repot dry. Do not water french lavender for several days first. Working with dry roots and dry mix dramatically lowers the rot risk for a succulent.
Pick a snug, fast-draining pot. Choose terracotta one size up at most, with a drainage hole. Have gritty free-draining, gritty, neutral to alkaline, low-to-moderate fertility ready.
Tip it out and clean the roots. Slide the plant out, crumble off the old soil, and trim any black, mushy or dead roots with clean snips.
Pot into dry mix. Set french lavender at its original depth in dry gritty mix, firming gently. Do not bury the stem deeper than it was.
Wait a week before watering. Leave it completely dry and out of harsh sun for about 7 days so any damaged roots callus. Only then water lightly.

Aftercare

Keep french lavender completely dry and out of fierce sun for about a week so any nicked roots callus before they meet moisture; watering a freshly repotted succulent is the classic way to rot it. Then resume the normal lean, dry rhythm. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for french lavender

French Lavender wants free-draining, gritty, neutral to alkaline, low-to-moderate fertility. Sharp drainage is essential. Improve heavy soils with grit; in pots use a loam-based mix with added grit or perlite and avoid moisture-retentive composts. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting french lavender — frequently asked questions

How often should you repot french lavender?

Every 2–3 years, into bone-dry mix for french lavender. Repot french lavender every 2–3 years into a snug pot of free-draining, gritty, neutral to alkaline, low-to-moderate fertility, ideally in spring or summer. Let it sit in dry soil and do not water for about a week afterwards so any nicked roots can callus. Over-potting and watering straight away is what rots succulents.

What size pot does french lavender need?

When is the best time of year to repot french lavender?

Should you water french lavender after repotting?

No — not straight away. Repot french lavender into dry mix and wait about a week before the first watering so any damaged roots callus over. Watering a freshly repotted succulent is the single most common way to rot one.

Should you fertilise french lavender after repotting?

Not immediately. Wait about 3 weeks after repotting french lavender. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.