How to Grow Lemon Verbena

Lemon verbena (Aloysia citriodora) is a woody shrub, and its narrow glossy leaves grow quickly in hot summer weather, replenishing as you harvest throughout the growing season. If you live in a USDA hardiness zone where lemon verbena is hardy (zones 8 through 11), the plant can become an anchoring shrub in your landscape releasing its citrusy aroma as you brush by. When used in culinary recipes, this herb has a lemony flavor and can be used as a substitute for fresh lemons or lemon zest. Its leaves can be used fresh or harvested and dried for future use.

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. While this herb is edible by humans, it is toxic to horses, dogs, and cats.

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 shade 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 transplants rather than seeds. Plant young plants 12 to 18 inches apart. You can train it to grow against a wall, fence, or trellis if you prefer.

Lemon Verbena Care

Light

Lemon verbena needs full sun six to eight hours per day, which is typical for a vegetable garden. Plants that are grown indoors as houseplants might need supplemental artificial lighting to prevent lanky growth and leaf drop.

Soil

Lemon verbena does well in rich garden loam, and it also tolerates average soil. However, good drainage is essential, so if garden bed soil is heavy and dense, plant them in raised beds or containers.

Water

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 two inches of soil are dry, water and aim for a moisture level that resembles a wrung-out sponge. Plants grown 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. Because lemon verbena is sensitive to frost, it might be best to grow it in a container so that you can move the container indoors during the winter.

Fertilizer

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 USDA 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, and it's not bitter.

Harvest leaves once the plant reaches at least ten 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 sauces, oil, sugar, or tea with whole leaves. The tiny blossoms of lemon verbena also carry a 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-released fertilizer, leaf mold, or compst to ensure a healthy start. Keep the container in full sun, water daily, offer a general fertilizer every few months, and if the pot is outdoors, overwinter it indoors once the temperatures drop to 40 degrees Fahrenheit.

Pruning

Lemon verbena growing in containers rarely exceeds two or three feet tall, but the shrubs can exceed eight 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 will provide more opportunities to enjoy its fragrance. 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.

1. With a sterile and sharp cutting tool, snip a four- to six-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.
2. Insert the cutting one inch deep into a moist, sterile potting mix. (Rooting hormone is not necessary, but you can use it if you prefer.)
3. Provide the cutting with a humid environment by placing the pot in a large clear plastic bag that is closed at the bottom. Make a one-inch nick at the top so moisture can escape.
4. Check the plant every other day by removing the bag to see if the soil surface is dry. If it is dry, add a light watering to moisten the soil. Lightly mist the cutting and the leaves if they feel dry.
5. After a few weeks, begin to gently tug on the plant to see if roots have developed. Once you feel resistance, take off the plastic bag and continue growing the plant indoors for two more weeks.
6. Transplant the cuttings into a four-inch container placed in the sun until it's time to plant cuttings in their permanent outdoor site in the spring.
   

Overwintering

Lemon verbena usually drops its leaves and enters dormancy when the temperature drops lower than 40 degrees Fahrenheit. Help plants prepare for winter by reducing watering a few weeks before the typical onset cooler temperatures. Provide extra winter protection by cutting plants back to within a couple of inches from the ground after the first hard frost and covering the remaining stub with soil. Cover the soil with a four- to five-inch layer of mulch

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.