How to Grow Lavender

Pick the right lavender for your climate

Most lavender failures start at the garden center, with the wrong species for the region. The types differ more in cold and humidity tolerance than in looks.

English lavender (Lavandula angustifolia) is the cold-hardiest and the source of true lavender oil. New Mexico State and NC State rate it for zones 5-9, while UF/IFAS rates it 5b-8 and notes it may decline in zone 8 because of summer heat. Colorado State says it often blooms twice in a season. It blooms early to midsummer.

Lavandins (L. x intermedia) are hybrids of English and spike lavender. They are larger plants with longer stems, bloom later (NC State says about 3 to 4 weeks after English lavender), contain more camphor and produce more oil of lower quality. New Mexico State rates them zones 5-9 and more heat tolerant than English lavender; Iowa State says they survive zone 5 only in a protected spot. Lavandins are sterile, so every plant is grown from a cutting.

Spanish lavender (L. stoechas) carries the plump, “pineapple” flower heads topped with petal-like bracts. It is heat tolerant but less cold hardy, and the ratings vary: zones 7-11 from New Mexico State, 8-9 from NC State, and about 10°F, or zone 8, from the University of Arkansas. Some selections are tougher. NC State lists ‘Silver Anouk’ for zones 6-9, and Arkansas reports ‘Otto Quast’ is said to be hardy to 5°F. Spanish lavender blooms from spring and keeps flowering through summer as long as it is growing.

French lavender (L. dentata), with toothed leaves, tolerates humidity and heat, has no frost tolerance and is rated zones 8-11 by New Mexico State. It may bloom all season. Labels are confusing here: many plants sold as “French lavender” are actually Spanish lavender, and NC State lists French lavender as one of L. stoechas’s common names. Check the Latin name.

Two others are worth knowing. ‘Goodwin Creek’ (L. x ginginsii) tolerates heat and humidity and is hardy to about 15°F, roughly zone 8, per New Mexico State. Fernleaf lavender (L. pinnata) is hardy only in zones 9-11 and is usually grown as a summer annual.

Varieties extension services recommend

• Iowa and the Upper Midwest (Iowa State): English lavenders ‘Munstead’, ‘Hidcote’, ‘Blue Cushion’ and ‘Royal Velvet’ are compact and relatively hardy. Lavandins ‘Grosso’, ‘Provence’ and ‘Phenomenal’ need a protected site; ‘Phenomenal’ has shown better tolerance of both cold and humidity than older cultivars.
• North Carolina (NC State): ‘Provence’ and ‘Grosso’ do well in western North Carolina, and ‘Hidcote’, ‘Munstead’ and ‘Superblue’ are often good choices statewide. ‘Phenomenal’ is hardy to zone 4.
• New Mexico (New Mexico State): English types include ‘Munstead’, ‘Hidcote’, ‘Compacta’, ‘Vintro’, ‘Delft Blue’, ‘Vera’ and ‘Pastor’s Pride’; lavandins include ‘Grosso’, ‘Provence’, ‘Hidcote Giant’, ‘Phenomenal’, ‘Super’, ‘Sensational!’ and ‘Riverina Thomas’.
• Colorado (Colorado State): both English lavenders and lavandins grow well; French and Spanish types are grown as annuals in beds and containers.
• Central Florida (UF/IFAS Pasco County): Spanish lavender is rated best and French lavender appropriate, along with ‘Phenomenal’ and ‘Goodwin Creek Grey’. English lavender is the hardest to grow there.

Buy plants that were propagated from cuttings. Colorado State warns that English lavender does not reliably come true from seed, so seed-grown plants can vary widely in height, width, color and bloom time.

When to plant

Lavender can go in during spring after the last frost or in fall; the dates for your zone above give the frost-based spring window. Colorado State cites New Mexico State research at Alcalde showing that fall-planted lavender survives better, establishes more quickly and produces more flowers the following season. The catch is plant size: fall plantings should come from 4-inch or larger pots with an established root system, while spring plantings can be smaller because they have a whole season to root.

Where winters are harsh and soils wet, spring is safer. Iowa State recommends planting after the risk of severe frost has passed. UC IPM gives California windows of April-May or September-November on the North Coast, April-May or September on the South Coast, April or October in the Central Valley, and March or September in the Imperial and Coachella valleys.

Sun, soil and drainage

Give lavender 6 to 8 or more hours of direct sun. Less light means floppy, open plants and fewer flowers.

Sharp drainage matters more than anything else. Root rot, which Iowa State calls the most common lavender problem, thrives in wet soil; Colorado State names Phytophthora as the soil disease to watch for. Iowa State notes that raised beds or berms are often necessary in clay, and NC State tells North Carolina growers to build raised beds, full stop. UC IPM adds a simple test: if moist soil forms a clump when squeezed, it is too wet; if it crumbles easily, it will do. Keep lavender out of reach of lawn sprinklers.

The best soil is sandy or gravelly, low in organic matter, and neutral to slightly alkaline, about pH 6.5 to 7.5 according to UC IPM and UF/IFAS Pasco. UF/IFAS stresses that lavender is very sensitive to pH and should be kept above 6; Iowa State suggests lime for acidic soils.

How to amend clay is one place sources disagree. Colorado State recommends tilling in 1 inch of small (¼-inch) bark mulch to a depth of 6 to 8 inches and warns that adding sand or gravel to clay can make drainage worse. The University of Arkansas, by contrast, suggests raised beds with a high proportion of sand or gravel for winter drainage. The safe approach on heavy clay is to build up rather than dig down: a raised bed or berm of fast-draining soil above the clay.

Spacing

Crowding invites disease, and lavender does not compete well with weeds. UF/IFAS spaces plants 24 to 36 inches apart. Colorado State uses 2 to 3 feet within rows and 3 to 6 feet between rows for crop plantings, and UC IPM 3 feet apart in rows 4 to 5 feet apart. Plan for the mature size: UF/IFAS Pasco points out that a small potted plant can grow into a shrub 3 feet across.

Watering

Newly planted lavender needs regular water through its first season. Colorado State’s schedule for its dry climate is water once or twice a week after planting until plants are established, then every 2 to 3 weeks for mature plants until buds form, and once or twice a week from bud formation until harvest.

Once established, lavender is drought tolerant, and overwatering does far more harm than underwatering. Drip irrigation is better than overhead watering, which UC IPM says can damage plants and promote disease. Colorado State notes overhead watering works fine in its low humidity, a reminder that the risk depends on how fast leaves dry.

In dry-winter areas such as the Colorado Front Range, Colorado State advises not letting the root zone dry out completely in winter, and notes that winter watering increases survival of new plantings.

Fertilizer and mulch

Lean soil makes better lavender. Rich soil and extra nitrogen push leafy growth at the expense of flowers and oil, and Iowa State says most lavender performs best with no fertilizer at all. If a soil test shows a real need, UC IPM suggests working in a 10-10-10 fertilizer at ½ to 1 pound per 100 square feet before planting, avoiding fertilizer while flowers develop, and giving mature plants none.

Use gravel or crushed rock rather than organic mulch, which traps moisture at the base of the plant. Keep any mulch away from the crown. In cold regions, Iowa State recommends a light winter cover of straw or evergreen boughs after the ground freezes, and warns against heavy mulches that hold water.

Pruning

Lavender blooms on new growth and turns woody, splits open and dies out in the center if left unpruned. New Mexico State lists die-out, woodiness and frequent replanting among the main challenges with lavender.

• Spring: when new green leaves start to emerge from the base, cut back about a third of the plant, per Colorado State. Remove winter-damaged and dead stems at the same time.
• After bloom: deadhead and lightly shape the plant. The University of Maryland says this can encourage a second bloom.
• Late season: stop pruning by mid-August (University of Maryland) so new growth can harden before winter.
• Never cut into bare wood. Lavender is a sub-shrub, and Iowa State notes it does not readily regrow from old wood. Maryland warns that cutting it back severely can kill it, and NC State says Spanish lavender does not tolerate being cut to the ground.

Even well-pruned plants decline with age, so plan to replace old, open plants with fresh cuttings every several years.

Regional growing notes

Cold north and Upper Midwest

Winter survival is the main challenge, and Iowa State says plants are most vulnerable when soils stay wet or go through repeated freeze-thaw cycles. Grow English lavender or a hardy lavandin, plant in a raised bed, and use only a light winter mulch. Where winter lows drop below about -10°F, NC State suggests rooting cuttings of favorite plants in early fall and keeping them indoors as insurance. In windy, snowy areas, Colorado State recommends fabric row covers to protect new plants through winter.

Humid South and Gulf Coast

Humidity and summer rain, more than heat, limit lavender here. The University of Arkansas describes lavenders as disdainful of cold, wet winters and summertime humidity, and NC State calls high humidity and rainfall the biggest challenges. English lavender usually fails on the Gulf Coast and in Florida.

Choose Spanish, French, ‘Phenomenal’ or ‘Goodwin Creek Grey’, plant in raised beds or containers, and space plants widely. UF/IFAS Pasco suggests some afternoon shade in Central Florida and warns that leaf spot is common in the warm, humid climate. Plant in fall so plants establish during the cool season, and expect short lives: the UF/IFAS Osceola County herb calendar lists September-October planting and treats lavender as an annual.

Arid West and Mountain West

Dry air, strong sun and alkaline soil suit lavender well, which is why Colorado State calls it a perfect plant for Colorado. The main risks are winter drying, poor drainage in heavy soils, grasshoppers, which can cut yields, and deer or elk browsing and trampling plants.

Warm-winter zones 9-11

Spanish and French lavender bloom from spring and may rebloom through summer, and French lavender tolerates no frost at all, which suits it to frost-free gardens. In Southern California, UC IPM recommends planting in April-May or September; in the desert valleys, March or September. English lavender rarely thrives where winters stay warm and summers are humid.

Growing lavender in containers

Containers are the way to grow tender types in cold regions and a way to guarantee drainage in wet ones. Iowa State notes potted lavender will not overwinter well outdoors there; grow it as an annual or bring it indoors for winter. UF/IFAS Pasco recommends raised beds or containers to improve drainage in Florida’s humid climate and notes potted plants need more frequent watering in summer. Use a pot with drainage holes and a fast-draining mix, and let it dry somewhat between waterings.

Propagating lavender

Cuttings are the most reliable method and the only one that reproduces a named variety. Colorado State recommends taking them right after the plants bloom, from stems with no flower buds. Strip the leaves from the bottom half, stick the cutting in well-draining sterile potting mix or horticultural vermiculite, water well and mist regularly. Rooting hormone is not needed, and cuttings should root in about 3 weeks. Move them into 2- to 4-inch pots, and plant out once roots fill the pot.

Seed is slow and uneven, often taking 2 to 4 weeks or longer to germinate, and plants vary. Iowa State’s method: chill seed in moist sand or peat in the refrigerator at 40°F for 2 to 4 weeks, sow on the surface of a well-drained seed mix, keep it evenly moist at 65 to 70°F, and give seedlings bright light. NC State notes one English cultivar, ‘Lady’, was bred to come true from seed and bloom in its first year.

Harvesting and drying

Cut stems in the morning, after the dew dries, when oil is most concentrated. For the best fragrance and color, harvest as the flower buds begin to open. Colorado State cuts when about half the buds have opened, while UC IPM and UF/IFAS advise taking stems for drying with only a few florets open, or before they open. Cut stems as long as possible.

Gather small bundles, secure them with a rubber band, which tightens as stems shrink, and hang them upside down in a dark, dry, well-ventilated place out of direct sun. Once dry, strip the flowers and store them in airtight containers.

Problems and how to fix them

• Plant wilts, browns and dies from the base: Phytophthora root rot from wet or poorly drained soil. Replant in a raised or gravelly bed, switch to drip, and water less.
• Spotted leaves in humid weather: fungal leaf spot from humidity and poor air flow. Space plants wider, avoid overhead watering and pick off infected leaves.
• Woody, sprawling plants with a dead center: age and missed pruning. Prune every spring and replace old plants.
• Few flowers, lots of leaves: too much shade or fertilizer. Move to full sun and stop feeding.
• Aphids, spittlebugs, spider mites, grasshoppers: usually minor. Iowa State says a strong spray of water handles most infestations, and UF/IFAS Pasco suggests insecticidal soap for aphids and spider mites if needed.
• Pets nibbling: NC State lists lavender as mildly toxic to cats, dogs and horses, and New Mexico State notes it is toxic to pets.