Herb · Lamiaceae
Lavender
Lavandula angustifolia
Give it full sun and sharp drainage, keep the ground lean, and lavender rewards you with fragrance for years.
Full sun
Every 10–21 days
USDA 5–9
18–35 in · 45–90 cm
Overview
Lavender is a Mediterranean subshrub in the mint family, valued for its silvery foliage and fragrant purple spikes. Adapted to poor, dry ground, it performs best on neglect and settles into a sunny, gravelly site where richer plants languish. Once its root system establishes, it withstands drought and heat with little intervention.
Its one demanding requirement is edaphic: lavender needs lean soil and sharp drainage before anything else. Rich ground and heavy irrigation keep water against the roots, which excludes oxygen and invites rot, and that is how most specimens are lost. Sited high and drained hard, watered sparingly, a single plant can persist for a decade or more.
Its usefulness extends past the ornamental border. The spikes dry well for sachets and the kitchen, they supply forage to bees across summer, and an annual shear holds the crown dense and compact rather than allowing it to go bare and woody. Kept lean and cut back, it retains its form and fragrance for years.
Care
The short version: full sun, lean and sharply drained soil, and minimal water once established. Prune every year after flowering, withhold fertilizer, and never allow water to pool around the crown.
Light
Site lavender in full sun, 6 or more hours a day. Below that threshold it develops leafy, bloom-poor growth and etiolates toward the available light. Direct sun also keeps the foliage dry, which limits fungal disease.
Water
Irrigate a young plant weekly only until it establishes, then reduce sharply. A mature lavender is drought-tolerant and requires no more than about half a gallon every couple of weeks, if that. Saturated soil is the fastest route to its death.
Soil
Grow it in lean, sandy or gravelly soil with sharp drainage. A pH of 6.5 to 7.5, neutral to slightly alkaline, suits it, and loam or shallow rocky soil serves equally provided it never waterlogs. Rich soil simply produces floppy, lax growth.
Temperature
English lavender is hardy across -4°F to 95°F (-20°C to 35°C) in zones 5 through 9. The operative threats are hard winters and cold, saturated soil, not summer heat.
Humidity
Lavender prefers dry air, about 30% to 50% humidity, and reacts poorly to muggy, stagnant conditions. In humid summers, wide spacing and free airflow keep fungal problems off the foliage.
Feeding
Feed almost nothing. A thin top-dressing of coarse compost at planting suffices, since richer feeding forces soft, lax stems and dilutes the fragrance. Lean ground yields the strongest scent.
Pruning
Shear the plant back by one-third to one-half each year immediately after flowering to maintain a compact form and extend its life. Keep every cut within green tissue and never enter the old bare wood, which rarely resprouts.
Repotting
For container specimens, repot every 2 to 3 years in spring into a pot only marginally larger, using a gritty, free-draining medium. Circling roots, rapidly drying mix, and sparse flowering signal that it has outgrown the pot.
Size & spacing
A mature plant attains roughly 18 to 35 inches (45 to 90 cm) in height and 24 to 35 inches (60 to 90 cm) in spread. Allow each that much room so air circulates freely and the foliage stays dry.
When to plant
Lavender germinates slowly but rewards a measured schedule once planted. Sow indoors in late winter, transplant in spring after the last frost when the soil has warmed, and the purple spikes emerge in early to mid-summer, cut just as the buds begin to open for peak oil content.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: late winter, 10-12 weeks before last frost; germination is slow and erratic
- Plant: spring after the last frost, once soil has warmed and drains freely
- Harvest: Purple flower spikes appear early to mid-summer; harvest spikes just as the buds begin to open for the strongest fragrance, and dry in a cool airy place
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Nearly every lavender disorder resolves to excess water or insufficient light, and most of the remainder to a neglected annual prune. Identify the symptom below, then correct the underlying condition rather than treating the sign alone.
Wilting and decline with soil that stays saturated
A wilt over wet soil points to root rot, frequently the water mould Phytophthora, and it remains the leading cause of lavender loss. The wilt is deceptive: saturated soil starves the roots of oxygen and lets the pathogen take hold, so the plant droops from failing roots rather than from drought. Withhold water, reset the plant onto a raised mound of gritty soil to restore sharp drainage, and discard any specimen whose roots have already gone dark and soft.
Fix:
- Stop supplemental watering immediately
- Replant into a raised bed, mound, or gritty sharply draining soil
- Discard plants with extensively rotted roots rather than trying to save them
No spring flush, or collapse coming out of winter
A lavender that stays brown into spring has typically taken winter damage, either direct cold injury in zone 5 and colder or crown and root rot induced by cold, wet soil. Because lavender breaks dormancy late, defer any verdict until late spring, then cut back to whatever live green wood remains. In hard-winter regions, plant into sharply drained, sheltered ground and favor proven cold-hardy cultivars such as 'Munstead' or 'Phenomenal'.
Fix:
- Wait until late spring before removing the plant, since lavender breaks dormancy late
- Cut back to any live green wood found
- Replace dead plants, choosing hardy cultivars such as 'Munstead' or 'Phenomenal'
Woody, bare base with growth pushed to the tips
As a subshrub, lavender lays down permanent woody stems, and without annual pruning that wood extends while active growth migrates to the branch tips, leaving it woody and leggy. Shear back by a third to a half immediately after flowering and keep the cuts within green tissue, because the old wood lacks the dormant buds needed to resprout. A specimen already collapsed into bare wood cannot be rebuilt and is best replaced from cuttings.
Fix:
- Shear back by one-third to one-half into green growth right after flowering
- Stay above the old bare wood, which rarely resprouts
- Replace very old, collapsed plants with new ones from cuttings
Spotted, yellow, or moldy foliage in crowded damp growth
Persistent leaf wetness is what drives fungal leaf spot, so it appears first in the shaded interior of a crowded plant where foliage never dries between waterings. The correction is cultural: widen the spacing and prune annually to open the canopy, water at the base in the morning so leaves dry by evening, and remove infected foliage to cut the inoculum. Airflow that dries the leaves suppresses the fungus more effectively than any fungicide.
Fix:
- Thin and space plants to improve air circulation
- Water at the base in the morning, keeping foliage dry
- Remove and dispose of affected foliage and debris
Vigorous foliage but scarcely any bloom
A lush but flowerless lavender is telling you it has too little sun or too much nitrogen. Flowering depends on six or more hours of direct sun and lean ground, whereas surplus nitrogen diverts the plant into vegetative growth at the expense of spikes. Relocate it into full sun, cease feeding to let the soil run lean, and confine pruning to the period after bloom so developing flower wood is not removed.
Fix:
- Move or transplant to a spot with 6+ hours of direct sun
- Stop fertilizing and let the soil stay lean
- Prune only after flowering so next season's bloom wood is not removed
Toxicity
Lavender registers as a mild hazard to animals rather than a serious toxin. The volatile oils of the foliage and flowers, principally linalool and linalyl acetate, can irritate a pet's digestive tract when eaten in quantity, and the concentrated essential oil is markedly more dangerous than the plant tissue. For people, the dried flowers function as a culinary herb, safe in small amounts.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds
Safe for
People
Cats Mild
The linalool in the volatile oils irritates the gut and can produce drooling, vomiting, and inappetence. A brief nibble typically resolves without intervention, but the concentrated essential oil poses a far greater danger to cats and must never be applied or fed.
Dogs Mild
A dog that chews foliage or flowers may show transient drooling, vomiting, and reduced appetite. The intact plant is a minor irritant; the material risk is undiluted lavender oil.
Horses Mild
Because horses cannot vomit, ingestion presents instead as a dulled appetite and mild colic-type discomfort. Small grazed quantities seldom advance beyond that.
Rabbits Mild
The aromatic oils that unsettle cats and dogs act similarly on rabbits, leaving one off its feed with digestive upset. Exclude it from the routine diet and offer no more than an occasional sprig.
Livestock Mild
Grazing stock generally avoid the strongly aromatic foliage, and an incidental taste produces little beyond a transient digestive upset. Only substantial intake warrants concern.
Birds Caution
No harm is documented, but the avian respiratory system is highly sensitive to strong aromatic oils, so prudence favors keeping lavender, and its oil above all, well away.
People Culinary use
The dried flowers serve as a culinary herb in small amounts for baking and tea and are safe to consume. The concentrated essential oil, however, does not belong in food.
The garden plant is a mild hazard, but concentrated lavender essential oil is far more dangerous, especially to cats - never apply oil to pets or let them ingest it.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
United Kingdom
Animal PoisonLine: 01202 509000 (fee applies)
Australia
Animal Poisons Helpline: 1300 869 738
Varieties
Lavenders separate chiefly on cold hardiness, mature size, and their tolerance of heat and humidity. The selections below are those a grower encounters most.
'Hidcote'
A compact selection to roughly 20 inches (50 cm) whose deep violet-blue spikes have secured its long reputation as a low edging plant.
'Munstead'
A compact, cold-hardy heirloom that performs reliably in zone 5 gardens where less hardy lavenders decline.
'Phenomenal' (Lavandula × intermedia)
A vigorous lavandin hybrid of bushy habit noted for strong winter hardiness and an uncommon tolerance of heat and humidity.
French lavender (Lavandula stoechas / L. dentata)
Recognized by its tufted rabbit-ear bracts and tender to roughly zones 8 to 11, so cold-climate growers treat it as an annual or a container subject.
How to propagate
Lavender propagates readily from cuttings and more slowly from seed, and only vegetative cuttings preserve a named cultivar true to type.
Stem cuttingsEasy
Summer, from non-flowering side shoots · 2-6 weeks to root in warm, moist potting mix
Cuttings give the most dependable increase and the only method that preserves a named cultivar's genetics. In summer, sever a non-flowering side shoot just below a node, strip the lower leaves to reduce moisture loss, and dip the base in rooting hormone. Held near 70°F (21°C) in a moist medium, it forms roots in roughly 2 to 6 weeks.
SeedModerate
Sow indoors in late winter, 10-12 weeks before last frost · 2-4 weeks to germinate; plants take a full season or more to reach flowering size
Seed is the slower and less predictable route. Sow indoors in late winter, 10 to 12 weeks before the last frost, and anticipate uneven germination across 2 to 4 weeks, with a full season or more before the seedlings reach flowering size. Because cultivars do not come true from seed, the resulting plants are genetically variable.
Myths
Lavender is completely safe for pets because it is a calming herb.
The ASPCA classes lavender as toxic to cats, dogs, and horses, and ingestion can produce mild nausea, vomiting, and inappetence. The concentrated essential oil is the genuine hazard, cats especially, and it should be kept well away from animals.
Lavender needs rich soil and generous regular watering to thrive.
Lavender performs best in lean, sandy, sharply drained soil and tolerates drought once established. Rich soil and frequent watering induce floppy growth and root rot, which is the most common cause of the plant's death.
Hard pruning into the old woody base will rejuvenate a leggy lavender.
Cuts into the bare old wood seldom yield new shoots, since that tissue holds few viable buds. Prune annually after flowering, removing no more than half and staying within green growth, and replace any specimen already largely woody.