The key to success in growing lemon verbena plants is providing a sufficiently warm atmosphere for these tropical herbs to thrive. With the exception of gardeners who live in the hot climates of USDA Hardiness Zone 9 or above, most individuals will need to grow lemon verbena indoors in a container in a sunny area. This tangy herb can be purchased at a garden center, propagated from cuttings, or started from seed.
Immature lemon verbena plants can be purchased at garden centers for planting in a container or outdoors. While lemon verbena plants sometimes grow to be 15 feet (4.6 m) tall, most container specimens will remain much smaller. Occasional pruning will help the plant produce more branches.
In locations with very warm conditions, lemon verbena plants can survive year after year outdoors. Wait until the last frost has passed to plant new seedlings. Before planting, mix compost into loosened soil. Make sure to leave more than 24 inches (61 cm) of space around each plant for maximum growth. Plenty of water will be required to allow lemon verbena plants to flourish outdoors.
Lemon verbena plants can be propagated from a cutting. All that is necessary to start a new plant is a tiny piece of stem that contains a few leaves. Stand the stem vertically in a jar with water, allowing it to begin sprouting roots, then transplant the cutting into a container with potting mix when its roots have grown beyond 1 inch (2.5 cm). If the seedling will later be planted outdoors, wait several weeks until the roots are well-established in a container.
Growing lemon verbena from seed requires small containers with a mix of perlite and peat moss. Moisten the planting medium, then plant a couple of seeds in the pot and cover them with additional potting mix. Cover pots with plastic wrap and place them in indirect sunlight. When sprouts appear, remove the wrap and place the pots in direct sun, watering frequently. Transfer seedlings to larger pots when they have grown substantially, and trim the roots slightly each time to keep the plant small for indoor use.
Lemon verbena, or aloysia triphylla, is an edible herb whose leaves and flowers have a lemony taste. The leaves can be used fresh or dried in herbal teas and in cooking a variety of fish, meat, or vegetable dishes. Some sources suggest using lemon verbena as a substitute for lemon zest or lemon juice in certain recipes. The strong lemony smell of lemon verbena plants is said to repel insects.