Verbena is a perennial plant available in tall, short and creeping varieties. The small, five-petaled flowers may be white, blue, red, cream, peach or purple, and many are quite fragrant. Gardeners use the shorter and creeping species as border plants and the taller ones to add jolts of color or coolness to mixed flower gardens.
If you’re growing verbena from seeds, start them indoors eight to 12 weeks before you intend to plant them outside, which should be after there’s no more danger of frost. Check with your county extension service to find out when the last frost usually falls in your area.
To germinate seeds, spread them out on a metal or plastic germinating tray, cover them with a very thin layer of potting soil and water lightly. According to the Wisconsin Master Gardener Program, verbena seeds germinate slowly and irregularly, so don’t give up immediately if they don’t all sprout at once or seem to be getting started slowly.
Plant verbena in full sun if possible, though it will grow in partial shade. Short varieties are particularly useful along driveways and in rock gardens.
Plant verbena seedlings outdoors after there’s no danger that it will frost.
Dig up the soil in the flower bed, down to about six inches.
Spread two inches to four inches of compost over the soil and mix it in well, to improve drainage.
Plant the seedlings two feet apart. Verbena plants will spread out and fill in the space between them, but they also need air circulation around their roots, to prevent mildew from developing.
Dig a hole for each plant that’s wide and deep enough for its roots to fit in comfortably.
Put the plant into the hole, making sure that the roots are not doubled up or crowded and that the top of the roots will be just about level with the top of the hole.
Fill in the hole around the plant gently.
Water the plants well, so that the ground around them is wet but not so much that big puddles of water are standing on it.
Continue to water the plants every two to three days until they’re established. Check for moisture by putting your fingers into the soil by the plants. If it’s completely dry or just barely moist, water the plants again.
Fertilize verbena once a month with a liquid, all-purpose plant food.