Lemon verbena is a tender perennial with an intense lemon aroma and flavor. Lemon verbena leaves are tougher, and it has a much higher volatile oil content, than many other lemon-flavored herbs like lemon balm, so it makes a superb choice for tea as well as for sachets. Lemon verbena requires little care other than regular harvesting to keep its growth thick and bushy, and winter protection outdoors, or a move indoors, in colder regions.
Plant lemon verbena in full sun in well-drained soil. Apply a 1/2-inch-thick layer of compost around newly planted lemon verbena, and top this with a 2-inch-thick layer of straw mulch to moderate soil temperature.
Water a newly planted lemon verbena daily for 1 week. Water weekly throughout the growing season. Water deeply, but allow the soil around the plant to dry out between waterings.
Prune one third of the lemon verbena back just before the plant flowers. Use pruners to snip approximately one third of the tallest stems back to about one quarter of their height. Harvest the leaves from the cut stems for desired herb uses.
When the lemon verbena's flowering begins to diminish in late summer, apply a dilute solution of liquid fish emulsion fertilizer to the base of the plant.
Before the first hard frost, prune the lemon verbena back to one half its standing height. Insert metal stakes or dowels into the ground around the plant, and wrap these with clear plastic sheeting. Fill with straw mulch or shredded leaves. Alternatively, fill a pot half-way with potting soil, dig a portion of the lemon verbena plant sized to fit your pot out with a shovel, and place it in the pot. Top off the pot with additional potting soil and bring the lemon verbena indoors to a sunny window for the winter months.