Broad-Leaved Lavender (Spike lavender) care

Light

Most houseplants will scorch where broad-leaved lavender thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. Full sun (6+ hours) is required for healthy growth and maximum oil production; plants in part shade grow loosely and fail to flower freely. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

Aim for every 2–3 weeks when established for broad-leaved lavender, but treat that as a starting point rather than a rule. A south-facing summer windowsill will dry the pot twice as fast as a north-facing winter room. Lift the pot; if it feels noticeably lighter than it did wet, water it. Drought-tolerant once established in the ground; water young plants regularly for the first season to establish deep roots, then reduce watering significantly.

Soil and pot

Broad-Leaved Lavender grows best in well-drained, alkaline to neutral loam or sandy soil, ph 6.5–8.0. Tolerates relatively poor soil well; avoid clay-heavy or waterlogged sites as standing moisture around the roots is fatal, especially in winter. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Broad-Leaved Lavender sits happiest at around Low (30–50% RH) humidity and -12°C to 38°C (10°F to 100°F). Best suited to low-humidity Mediterranean-type climates; in humid regions, raised beds and good spacing help prevent fungal disease on the broad foliage. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed broad-leaved lavender sparingly. Light application of a balanced fertiliser in early spring only; this species thrives in lean conditions and over-feeding reduces aromatic oil content. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on broad-leaved lavender in the Growli community. Each is annotated with the most common cause so you know where to start.

• Winter dieback in cold-wet soils — The combination of cold and waterlogged soil causes crown rot; plant on a slope or raised bed and mulch with gravel around the crown rather than organic matter.
• Xylella fastidiosa (high-risk pest) — Spike lavender is a confirmed host of Xylella fastidiosa, a bacterial disease spread by sap-sucking insects that causes rapid wilt and plant death. This is a notifiable pest in the UK and EU — report suspected cases immediately to the relevant plant health authority.

Propagation

Take semi-ripe heel cuttings in summer, root in sharp sand or perlite in a cold frame. Division of mature clumps in spring is also possible for established plants. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Broad-Leaved Lavender is toxic to pets. ASPCA lists Lavandula spp. as toxic to cats, dogs, and horses. The toxic principles linalool and linalyl acetate cause nausea, vomiting, and loss of appetite on ingestion. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Broad-Leaved Lavender deep-dive guides

Every aspect of broad-leaved lavender care, each with its own calibrated guide:

• Common broad-leaved lavender problems & fixes
• Broad-Leaved Lavender watering schedule
• Broad-Leaved Lavender light requirements
• Best soil mix for broad-leaved lavender
• Broad-Leaved Lavender fertilizing guide
• When to repot broad-leaved lavender
• How to propagate broad-leaved lavender
• How to prune broad-leaved lavender
• What's eating my broad-leaved lavender?
• Broad-Leaved Lavender growth rate & size
• Broad-Leaved Lavender cold hardiness
• Broad-Leaved Lavender temperature & humidity
• Is broad-leaved lavender toxic to cats & dogs?
• Is broad-leaved lavender toxic to cats?
• Is broad-leaved lavender toxic to dogs?
• All 25 Lavandula varieties

Related guides

Broad-Leaved Lavender is also known as Broad-leaved lavender, Spike lavender, and Portuguese lavender.

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