When it comes to lemon-scented herbs, lemon verbena (Aloysia citriodora) has the most intense oil concentration per square inch of plant material. This plant is beloved as an additive to drinks, baked goods, or anywhere you might use lemon zest; it's not bitter either. The spear-shaped leaves of lemon verbena grow quickly in hot summer weather, replenishing the plant as you harvest throughout the growing season. If you live in a perennial zone where lemon verbena is hardy (zone 8 through 11), the plant can become an anchoring shrub in your landscape, releasing its citrusy aroma as you brush by. Set your plants out at the same time you plant tomatoes, coleus, and other warm-weather lovers. It grows quickly and yields the most intense flavor in full sun.
|Botanical Name||Aloysia citriodora|
|Common Name||Lemon verbena, lemon beebrush, vervain|
|Plant Type||Tender perennial in frost-free zones|
|Mature Size||6 feet where hardy|
|Sun Exposure||Full sun|
|Soil Type||Rich and moist|
|Soil pH||Slightly acidic; 6.1 to 7.0|
|Bloom Time||Late summer|
|Flower Color||Purple buds open to white blossoms|
|Hardiness Zones||USDA growing zones 8 through 11|
|Native Area||South America, especially Chile and Peru|
|Toxicity||Mildly toxic to cats, dogs, and horses|
Lemon Verbena Care
The fragrance and size of lemon verbena plants make them a valuable addition to the back of the sunny herb border. A site with full sun, rich soil, and regular moisture will quickly grow for the harvest.
Lemon verbena growing outdoors in full sun and rich soil is rarely plagued by pests. When brought indoors to overwinter, spider mites and whiteflies seem to be drawn to the plants as they struggle to acclimate to weaker light and less humidity. Mist plants frequently to disrupt the dry conditions that spider mites enjoy. Put out yellow sticky traps if whiteflies congregate.
Lemon verbena needs full sun, similar to what roses or a vegetable garden would need. Situate your lemon verbena plants where a neighboring tree or building won't overshadow them. Plants that grow indoors as houseplants may need supplemental artificial lighting to prevent lanky growth and leaf drop.
Lemon verbena does well in rich garden loam, and it also tolerates average soil. However, good drainage is essential for healthy lemon verbena plants, so you must plant them in raised beds or containers in areas with clay.
Lemon verbena needs regular irrigation. A lack of water leads to plant stress, leaf drop, and insect pest infestation. Keep the surface of the soil moist, but don't oversaturate the plants. Aim for a moisture level that resembles a wrung-out sponge. Plants kept indoors for the winter months may be kept on the dry side.
Temperature and Humidity
In its native South America, lemon verbena plants grow in a sunny, frost-free climate. Temperatures below 40 degrees Fahrenheit will trigger leaf drop and dormancy. Plants do well in dry or humid environments.
Unlike other herbs, lemon verbena appreciates a regular fertilizing schedule to keep it lush and vigorous. Feed plants in the spring with an all-purpose fertilizer. Watering with compost or manure tea during the growing season will keep plants productive.
Harvesting Lemon Verbena
Harvest leaves once the plant reaches at least 10 inches tall and has multiple leaves on each stem. When lemon verbena flowers, the leaves are at their most flavorful. Cut back stems to within 1/4 of a leaf or node. Remove no more than 1/4 of the stem when harvesting so that the plant can continue growing. Because the leaves are tough, you must mince them finely if you plan to consume them. You can also infuse sauce, oil, sugar, or tea with whole leaves. The tiny blossoms of lemon verbena also carry their heady scent and can be used in the same way as the leaves.
Lemon verbena plants growing in containers rarely exceed 2 or 3 feet tall, but the shrubs can exceed 8 feet outdoors in frost-free climates. Over time, the shrubs can get woody and lanky. Cut plants back by half in early spring to encourage compact, bushier growth.
Propagating Lemon Verbena
Lemon verbena is propagated in the same way as other woody herbs like rosemary and lavender—by taking semi-ripe cuttings. Snip a flower-free stem above a leaf node. Remove all but the top two sets of leaves and insert the cutting into a moist, sterile potting mix. Keep moist until new leaves begin to form. Transplant into a sunny site with good drainage.
How to Grow Lemon Verbena From Seed
Lemon verbena flowers produce few viable seeds. Those that are produced rarely germinate. Gardeners should start with young lemon verbena plants rather than seeds.
Potting and Repotting Lemon Verbena
Pot your lemon verbena in rich potting soil. Amend the soil with leaf mold or composted manure to ensure a healthy start. Growing lemon verbena in a container is ideal for cultivating the plant all year in colder regions; container-grown lemon verbena also stays a more manageable size than plants grown in the ground.
Choose a potting soil enriched with time-release fertilizer to give plants a head start. Keep the container in full sun and water daily. Bring your plant indoors or to a greenhouse when temperatures drop below 40 degrees Fahrenheit. Potted plants moving indoors for the winter will lose leaves. Repot plants in the spring before new growth begins.
Lemon verbena usually drops its leaves when go lower than 40 degrees Fahrenheit, entering dormancy. Help plants harden off by reducing watering a few weeks before the typical onset of below-freezing temperatures. Provide extra winter protection by cutting plants back to within a couple of inches of the ground after the first hard frost and covering the remaining stub with soil. Cover the soil with a 4- to 5-inch layer of mulch or a microfoam ground cover packing material held down with soil also works well.
Lemon Verbena vs. Lemon Balm
Lemon balm (Melissa officinalis) and lemon verbena have similar uses in the kitchen. Lemon balm is a hardy perennial and will return in the landscape each year in zones 3 to 7. However, as a member of the mint family, lemon balm spreads vigorously and can become invasive. On the plus side, it is more shade-tolerant than lemon verbena. You can distinguish lemon balm from lemon verbena by its rounded, wrinkled leaves on low-growing plants. Although both plants have a strong lemon scent and flavor, lemon balm has a somewhat astringent tone, whereas lemon verbena is more floral.