Lemon verbena's (Aloysia citriodora) spear-shaped leaves 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.
|Common Name||Lemon verbena, lemon beebrush, vervain|
|Botanical Name||Aloysia citriodora|
|Plant Type||Tender perennial in frost-free zones|
|Mature Size||6 ft. where hardy|
|Sun Exposure||Full sun|
|Soil Type||Rich and moist|
|Soil pH||Slightly acidic (6.1 to 7.0)|
|Bloom Time||Late summer|
|Hardiness Zones||8-11 (USDA)|
|Native Area||South America, especially Chile and Peru|
|Toxicity||Mildly toxic to cats, dogs, and horses|
How to Plant Lemon Verbena
When to Plant
Lemon verbena prefers warm weather. Plant your lemon verbena in the spring after the last frost.
Selecting a Planting Site
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 and well-drained soil, and regular moisture will quickly grow for the harvest. Situate your lemon verbena plants where a neighboring tree or building won't overshadow them.
Spacing, Depth, and Support
Lemon verbena flowers produce few viable seeds. Those that are produced rarely germinate. Gardeners should start with young lemon verbena plants rather than seeds. Plant young plants 12 to 18 inches apart for best bushing. You can choose to train it to grow against a wall, fence, or trellis if you prefer.
Lemon Verbena Care
Lemon verbena needs full sun, similar to what roses or a vegetable garden would need. 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 that have 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; The roots do not like to stay wet. When the top 2 inches of soil are dry, then water and aim for a moisture level that resembles a wrung-out sponge. Plants kept indoors for the winter months can be watered once a week, but 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.
Lemon Verbena vs. Lemon Balm
Lemon verbena and lemon balm (Melissa officinalis) 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.
Harvesting Lemon Verbena
When it comes to lemon-scented herbs, lemon verbena 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.
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. But refrain from simply plucking the leaves off a stem; The stem needs to be cut back 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.
How to Grow Lemon Verbena in Pots
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 container of any material, but double the size of the plant's root ball. The pot should have numerous drainage holes. Add loose potting soil enriched with time-release fertilizer, leaf mold, or composted manure to ensure a healthy start. Keep the container in full sun, water daily, offer a general fertilizer every few months, and if the pot lives outdoors, overwinter indoors once the temperatures drop.
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, lanky, and they generally can look worn out. Cut plants back by a third to half in early spring to encourage compact, bushier, and thicker growth.
Propagating Lemon Verbena
If you love the aroma of lemon around your property, propagating lemon verbena from an existing bush to give you more places inside and out to add the fragrant plant. Plus, if you are an avid user of its leaves for potpourri, tea, or other recipes, you can save money cultivating your own supply instead of buying pricy leaves from a retailer. Lemon verbena is propagated in the same way as other woody herbs like rosemary and lavender—by taking semi-ripe cuttings in the summer.
- With a sterile and sharp cutting tool, snip a 4- to 6-inch flower-free stem above a leaf node. The stem should be about 1/4 inch in diameter. Remove all but the top two sets of leaves.
- Insert the cutting 1 inch deep into a moist, sterile potting mix. (Rooting hormone is not necessary, but you can use it if you prefer.)
- Give the cutting a humid environment by placing the pot in a large clear plastic bag that is closed at the bottom, but with a 1-inch nick at the top so moisture can escape.
- Check the plant every other day by removing the bag and checking if the top of the soil is dry. If it is dry, add a light watering to moisten the top. Lightly mist the cutting and the leaves if they feel dry.
- After a few weeks, begin to gently tug on the plant to see if there are roots. Once you feel there are roots, take off the plastic bag for two more weeks.
- Transplant the plant into a 4-inch container placed in the sun until it's time to plant cuttings in their permanent outdoor site in the spring.
Lemon verbena usually drops its leaves and enters dormancy when the temperature goes lower than 40 degrees Fahrenheit. 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, which works well when held down with soil.
Bring your potted lemon verbena plant indoors or to a greenhouse when temperatures drop below 40 degrees Fahrenheit. Potted plants moving indoors for the winter will typically lose leaves. A grow light may prevent leaf loss, but it is not necessary.
Common Pests and Plant Diseases
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.
Is lemon verbena easy to grow?
It's easy if you begin with a small plant, but not so easy if you try to grow lemon verbena from seeds.
How long does it take to grow lemon verbena?
Lemon verbena grows fast when you plant it in the spring, and the leaves continue to grow if they are harvested in the summer. Growing lemon verbena from seeds is extremely slow-going, and not recommended for home gardeners.
Can you grow lemon verbena indoors?
Lemon verbena grows large, so it can be a challenge to grow indoors, and it's not the best addition to a windowsill garden. But if you have the space for a pot well over 12 inches in diameter, a spot with plenty of sun, and you're willing to regularly prune the plant to keep its size in check, you can definitely try growing it indoors.
What are the best companion plants I can grow with lemon verbena?