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Fertilising guide

How to fertilise Lavandin (Lavandula x intermedia)— schedule & NPK

Also called Lavandin, Dutch lavender, Hybrid lavender.

More about lavandin

About Lavandin

Lavandula x intermedia · also called Lavandin, Dutch lavender · herb

A naturally occurring and cultivated hybrid between Lavandula angustifolia and L. latifolia, lavandin is larger, more vigorous, and more heat-tolerant than English lavender. Its tall, branched flower stems and strongly camphorous-floral fragrance make it the dominant lavender of the French and Spanish essential-oil industry. Superb for large garden borders, hedging, and dried flower production.

Growth habit: Large, vigorous, mound-forming woody-based evergreen subshrub; typically larger than either parent species; sterile (no viable seed)

What fertiliser lavandin actually wants — and why

Lavandin is a lean, aromatic herb — the essential-oil flavour you grow it for is strongest in poor soil, so feeding it actively makes it worse.

Little or nothing. If anything, a very weak balanced feed or a thin compost top-dress — never a rich nitrogen feed, which dilutes the aromatic oils and produces soft, bland, floppy growth.

For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for lavandin: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.

How often to feed lavandin, and which months

Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For lavandin:

Minimal feeding required. Lean soils produce the most aromatic, compact plants. A light potassium feed in spring is the maximum recommended. Avoid all nitrogen-rich fertilisers. In practice: a spring compost top-dress at most, and otherwise leave lavandin unfed — lean, sharp-draining soil is exactly what concentrates its flavour.

The dormant-season rule matters more than the exact interval: skip feeding entirely when lavandin is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.

What strength to mix for lavandin

As weak as it gets for lavandin, or none at all. The flavour-versus-growth trade-off runs the opposite way to leafy crops: restraint is the technique.

Feeding always goes onto already-damp soil, never dry roots — water lavandin first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the lavandin watering schedule.

Signs you are over-feeding lavandin

Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for lavandin:

Signs you are under-feeding lavandin

If the symptoms point at watering, light or roots rather than nutrition, the full lavandin care brief covers soil, humidity and the common problems for this species.

Flushing and leaching the salts

Over-feeding is so unlikely with lavandin that flushing is rarely needed; if a container has had feed, a single plain-water flush and a switch to a leaner, grittier mix resets it.

Organic vs synthetic feeds for lavandin

Organic options

A thin spring mulch of garden compost or leaf-mould is the most these want. UK: a little garden compost; US: a light Espoma Garden-tone top-dress at most. Lean and gritty beats fed and rich every time.

Synthetic / liquid feeds

Generally none for lavandin. At absolute most, a very dilute balanced feed once or twice in a container; in the ground, nothing — synthetic feeds work directly against the flavour.

Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.

Fertilising lavandin — frequently asked questions

What fertiliser does lavandin need?

Little or nothing. If anything, a very weak balanced feed or a thin compost top-dress — never a rich nitrogen feed, which dilutes the aromatic oils and produces soft, bland, floppy growth. Lavandin is a lean, aromatic herb — the essential-oil flavour you grow it for is strongest in poor soil, so feeding it actively makes it worse.

How often should I feed lavandin?

Minimal feeding required. Lean soils produce the most aromatic, compact plants. A light potassium feed in spring is the maximum recommended. Avoid all nitrogen-rich fertilisers. Minimal feeding required. Lean soils produce the most aromatic, compact plants. A light potassium feed in spring is the maximum recommended. Avoid all nitrogen-rich fertilisers. In practice: a spring compost top-dress at most, and otherwise leave lavandin unfed — lean, sharp-draining soil is exactly what concentrates its flavour.

What strength of feed for lavandin?

As weak as it gets for lavandin, or none at all. The flavour-versus-growth trade-off runs the opposite way to leafy crops: restraint is the technique.

What does over-feeding lavandin look like?

Lush, soft, fast growth with noticeably weaker scent and flavour. Floppy stems, sparse essential oils, and poor cold/wet hardiness. Salt crust in containers and scorched leaf tips from over-feeding. Feeding lavandin like a leafy vegetable is the defining mistake — rich nitrogen gives you a big, soft, fast plant whose leaves are watery and bland, with weak winter-rot resistance.

Should I flush the soil of lavandin?

Over-feeding is so unlikely with lavandin that flushing is rarely needed; if a container has had feed, a single plain-water flush and a switch to a leaner, grittier mix resets it.

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