Knowing how to grow verbena is a matter of understanding its needs. By following some basic rules, you will have verbena thriving in your garden. Verbena does well in climate zones two through seven. It needs full sun, minimal fertilizing, and prefers frequent watering. In mild climates, it grows as a perennial, and in harsher climates, it grows as an annual. Verbena is an herbaceous, ornamental plant, known for a long blooming season, from spring to early fall, with vibrant blue, purple, red, pink or white blossoms.
Start verbena from seed, cutting, or transplant. Start seeds indoors in late winter. Germination is slow, and it may take a month to see any sprouts. In spring, when they are large enough to handle, transplant small plants outdoors in full sun, spaced 10 to 12 inches apart. Cuttings taken in spring root well and can move to the garden later in the season. Once outside, verbena grows moderately fast, often with plentiful first year blooms. After transplanting outdoors, pinch the tops of the plants to promote full growth and dense blooms.
Keep young verbena plants moist. Established plants are somewhat drought tolerant but their soil should not dry out completely. Give each plant a thorough watering once a week. Apply 16-4-8 or similar fertilizer once or twice a year in early or late spring and perhaps in midsummer. To extend the blooming season, deadhead spent flowers. When grown as an annual, verbena often reseeds itself for the following year, so consider allowing some flower heads to go to seed. In the fall, cut back perennials and remove annuals from the ground.