Herb · Verbenaceae
Lemon Verbena
Aloysia citriodora
Brush the narrow green leaves and lemon lifts into the air. Give it full sun and warmth, and this tender herb fills out with fragrant foliage.
Full sun
Every 3–7 days
USDA 8–11
2–6 ft · 0.6–1.8 m
Overview
Bruise a single narrow leaf of lemon verbena and a clean, sweet lemon scent lifts off it, sharper than most true citrus. That fragrance sends the leaves into tea, syrups, and cooking. The plant builds itself as a loose, woody shrub, comes from South America, and is grown the world over for the scent of those leaves.
It is a frost-tender perennial, holding through winter outdoors only in the mild zones 8 to 11. Where the cold bites, the plant lives in a pot and shelters inside, or runs as an annual and starts over each spring. Its woody stems can stretch to 6 feet (180 cm) of open, leggy growth, so a pinch here and there keeps the framework full rather than bare.
Late in summer the shrub opens tiny white to pale lilac flowers in loose, airy clusters above the green leaves. The plant sulks and sheds those leaves after a move or a chill, then dresses its stems again once it settles. With sun, warmth, and even moisture, it holds its fragrant foliage from spring straight through the season.
Care
The short version: full sun and warmth, soil kept evenly moist but never soggy, a monthly feed through the growing season, and shelter or a move indoors before the first frost.
Light
Lemon verbena wants full sun, ideally 6 or more hours a day, which packs the narrow leaves with scent and holds the growth tight. A little afternoon shade does no harm, but heavy shade thins the leaves and leaves the stems floppy with a weaker fragrance.
Water
Keep the soil evenly moist but well drained, watering more often in pots or through a heat spell. A swing between bone-dry and waterlogged strips the leaves from the stems, so an even hand keeps the foliage on the plant.
Soil
Set it in well-drained loam worked with organic matter. It sits comfortably across a fairly wide pH from 6.0 to 7.5, and good drainage counts for far more than the exact number.
Temperature
It grows across roughly 23°F to 86°F (-5°C to 30°C), though it is frost-tender at the low end and sheds its green leaves in the cold. Below 40°F (4°C) it suffers, so a potted plant belongs indoors before the first hard chill.
Humidity
Average humidity of 40% to 60% suits it outdoors. The dry indoor air of winter invites spider mites onto the leaf undersides, so a little added moisture and moving air keep the foliage clean and green.
Feeding
Feed it monthly through spring and summer during active growth with a balanced general-purpose fertilizer. A container plant takes a lighter hand, since it cannot shrug off an overdose the way a garden plant can.
Pruning
Prune in spring to shape the woody framework and clear dead or weak wood, and pinch the growing tips through the season to thicken the leafy growth. After it overwinters, cut the stems back hard once fresh growth breaks.
Repotting
Move it up every 1 to 2 years in spring into the next pot size. Roots circling the pot, water rushing straight through, or fast wilting between waterings all mark the time for fresh soil around the roots.
Size & spacing
Expect a loose, woody shrub of 2 to 6 feet (60 to 180 cm) tall spreading 3 to 4 feet (90 to 120 cm) across. Give it that room so air moves through the open, leafy stems and the framework has space to fill.
When to plant
Lemon verbena waits on warmth and will not stand frost. The tender stems go outside only once the cold has cleared and the nights have warmed in late spring, the narrow leaves come off all season, and tiny white to lilac flowers open in loose clusters as summer closes.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: After all danger of frost has passed and soil and nights are warm (late spring)
- Harvest: Tiny white to pale lilac flowers in open clusters in late summer; harvest fragrant leaves throughout the growing season, most aromatic just before flowering
Hardiness
USDA hardiness zones: 8–11
Temperature: down to -12°C
Troubleshooting
Lemon verbena shows its state in the leaves, which fall or fade from green when something is off. Most of the trouble comes down to cold, uneven watering, or the dry air of an indoor room. Match the look below and settle the cause before more of the foliage goes.
A wilting plant over soft, dark roots
The leaves droop and yellow while the roots below turn soft and brown, a picture of root rot in soil that stays wet and sour. Less water, a lift from the pot, and a trim of the mushy roots come first, then fresh, fast-draining mix around the healthy ones. A pot with open drainage holes keeps the roots firm and pale again.
Fix:
- Reduce watering and improve drainage
- Repot into fresh, well-drained mix, trimming away rotted roots
- Use containers with drainage holes
Bare stems where the leaves fell
When the slender green leaves let go and leave the woody stems bare almost overnight, the cause is usually transplant shock or a chill below 40°F (4°C). Soil that lurches from bone-dry to soggy pulls the leaves off too. Held in one spot with even watering, the plant clothes those stems again in fresh growth once it settles.
Fix:
- Stabilize the plant's environment and avoid further moves
- Keep soil evenly moist and out of cold drafts
- Be patient; new leaves usually flush once conditions stabilize
Pale-flecked leaves veiled in fine webbing
The bright green leaves turn dull and flecked with pale dots, and a thin webbing films the undersides, the mark of spider mites that thrive in dry indoor air. Whitefly and aphids wash the same leaves yellow. A hard rinse, insecticidal soap worked over the leaf undersides, and more moving air and moisture indoors strip the mites away.
Fix:
- Rinse foliage with a strong spray of water
- Treat with insecticidal soap or horticultural oil, covering leaf undersides
- Increase air circulation and humidity for indoor plants
Toxicity
There is nothing to fear on the leaf or the stem: lemon verbena is safe all around. It is a culinary herb grown for tea and cooking, and no part of its green foliage or woody growth harms pets, livestock, or people. It can grow anywhere in the home.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Nothing in the green leaves or woody stems is toxic to cats. A curious bite of a leaf may bring a brief, mild stomach upset, the same as with almost any plant.
Dogs None
The plant carries no toxin that troubles dogs. The sharp lemon scent rising off the leaves usually keeps them from chewing much of it.
Horses Safe
The foliage holds nothing that would harm a horse, so a grazing horse has no cause for concern.
Rabbits Safe
The narrow, fragrant leaves are safe for rabbits and make a pleasant occasional treat beside their usual greens.
Livestock Safe
Cattle, goats, and sheep can browse the leafy stems without harm, since they hold no toxin that affects them.
Birds Safe
The plant is no threat to birds, whether they pick at the leaves outdoors or share a room with it inside.
People Safe
The slender green leaves are a kitchen favorite, steeped into a bright lemon tea or used to flavor food, and they are safe to eat.
Leaves are edible and aromatic; no special handling precautions are needed beyond normal kitchen use.
Varieties
Lemon verbena reaches the shelf almost always as the plain species, so there is little to sort between. The note below covers what to expect from the plant you bring home.
Lemon verbena (species)
It almost always appears as the plain species rather than a named cultivar, and its narrow green leaves give off the most intense lemon scent of the common kitchen herbs.
How to propagate
The sure way to more lemon verbena runs through cuttings, since its seed rarely sprouts. A piece of a plant you already have grows into the same narrow-leaved, lemon-scented shrub.
Stem cuttingsModerate
Late spring through summer using softwood or semi-ripe growth · Roots typically form in about 3-4 weeks, with established plants in 1-2 months
Cuttings taken from the soft, non-flowering shoot tips in late spring through summer root well once the lower leaves are stripped from the stem and the base is set in a moist, well-drained mix kept warm and humid. Pale new roots push out in about 3 to 4 weeks, and over the following month or two the leafy cuttings thicken into established plants. Seed is a poor bet here, rarely sold and slow to sprout.
Myths
Lemon verbena is a hardy herb that survives winter outdoors anywhere.
Its leafy, tender stems are frost-sensitive, and the plant returns dependably only in the mild zones of about 8 to 11. In colder ground it comes indoors for winter or grows as an annual, replanted each spring.