The Verbena genus contains more than 250 species of perennial and annual plants. The pure species are not commonly grown except by fairly specialized gardeners. Most of the Verbenas widely used as bedding plants or low trailers in containers are named cultivars derived from hybrid crosses of various native verbena species. You often will see these labeled as "Verbena x hybrida", "Verbena x" or "annual verbena" to distinguish them from the native species forms.
These hybrid verbenas may perform as hardy perennials in zones 9 to 11, but they are more commonly grown as annuals in all zones. They are usually low-growing, trailing plants with dark green leaves and clusters of colorful flowers that bloom continuously from spring to fall.
As annuals, these plants are generally planted in spring, as soon as all danger of frost has past. Like most annuals, they are fast-growing and achieve full size within a few weeks.
|Botanical Name||Verbena x|
|Common Names||Verbena, annual verbena|
|Plant Type||Herbaceous perennial, usually grown as an annual|
|Mature Size||Up to 12 inches tall, 18-inch spread (depends on variety)|
|Sun Exposure||Full sun|
|Soil Type||Dry to medium-moisture, well-drained soil|
|Soil pH||5.8 to 7.2 (acidic)|
|Bloom Time||Spring to fall|
|Flower Color||White, red, purple, pink, peach (depends on variety)|
|Hardiness Zones||9 to 11 (USDA)|
|Native Area||Cultivated hybrid; parent species mostly native to Europe|
How to Grow Verbena
Hybrid annual verbenas are best grown in relatively dry soil in a sunny location. There is very little care necessary, other than regular watering.
These plants are susceptible to powdery mildew, and they may be visited by common insect pests that can be treated with insecticidal soaps or chemical sprays. Such problems are rarely fatal to the plants, however.
Plant verbena in full sun. Flowering will be much reduced in shady locations. This is a plant that requires 8 to 10 hours of sun daily.
These plants like a fairly dry soil with an acidic pH. Verbena is not particular about soil, except that it must be well-draining. Heavy clay will lead to root rot, so dig in several shovelfuls of compost or leaf mold to lighten your soil.
When planted in containers, any general-purpose peat-based potting mix will be fine.
Keep plants evenly moist until established. Once mature, these plants have average water needs, but will readily tolerate short periods of drought. Many of the parent species of these hybrids are native to Mediterranean regions or dry prairies, and their water needs resemble the conditions of those regions.
Temperature and Humidity
Planted as annuals hybrid verbenas perform suitably in virtually any climate, but may decline in the hottest period of the summer.
Verbenas are not heavy feeders, but they do appreciate a monthly application of balanced, slow-release flower fertilizer to help them keep up the flower show, which can last from spring until frost.
Verbenas are so inexpensive as nursery seedlings that gardeners rarely feel the need to propagate them. You can, however, take stem cuttings and root them in a gritty seed-starter mix. Take 3-inch stem cuttings, strip off the lower leaves, and plant them in seed starter mix. Moisten the soil, then place the pot in a sealed plastic bag to hold in moisture. After a few weeks, you should see new growth starting, indicating that the cutting has rooted and can be transplanted into the garden or into a larger container.
Growing from Seeds
Though normally planted from nursery seedling packs, verbenas are easy to grow from purchased seeds. Soak the seeds in lukewarm water for 24 hours prior o planting. Plant the seeds in starter trays filled with a peat-based potting mix, pressing the seeds lightly into the mix, then sprinkling peat moss over the seeds. Cover the tray with newspaper or plastic with ventilation holes punched in it (the seeds need darkness to germinate). Uncover the tray when the seedlings sprout and transplant them into their garden location.
These plants often self-seed in the garden, and the volunteers will "grow true" to the parent plants.
Growing in Containers
For container planting, use any general-purpose potting mix with a peat base, in a well-draining container. In mixed containers, Verbena is normally used as a "spiller" plant to trail over the sides of the container.
Hybrid annual verbenas are constant bloomers that are often used as garden bedding plants, planted in masses, or as front edging plants where the sprawling habit is put to good use. They are also very common in hanging baskets or containers, where they make good "spillers" trailing over the sides.
Verbena is both a deer and rabbit resistant plant, so take advantage of this by planting it at the edge of your property where animals frequently browse.
Varieties of Annual Verbena
The various varieties of hybrid verbena are usually identified by their unique flower colors. Some notable selections include:
- 'Lanai Royal Purple with Eye' (Verbena x hybrida 'Lanai Royal Purple with Eye' is a cultivar with bright purple flowers and contrasting white eyes.
- 'Texas Rose' (Verbena x hybrida ‘Texas Rose’) is a cultivar that bears reddish-pink flowers.
- 'Blue Princess' (Verbena x hybrida ‘Blue Princess’) is a newer hybrid variety of verbena that produces beautiful deep blue flowers.
- Superbina’" series is bred to resist powdery mildew and it sometimes becomes a short-lived perennial as far north as zone 7. Flowers are white or shades of lavender.
In addition to the Verbena hybrids that are so common as annual bedding and container plants, there are a number of pure Verbena species that you can try as garden perennials, though finding them can be a challenge. These species are welcome in the butterfly garden. Tall varieties belong in the cottage garden, naturalized meadow, or back of the border.
Many of these plants are more upright in growth habit and may look quite different from the hybrid trailers.
- V. hastata (blue vervain) is a North American native that grows to 6 feet tall with purplish-blue flowers. It is hardy in zones 3 to 8.
- V. bonariensis is a native of Brazil that grows to 4 feet with lavender flowers. It is hardy in zones 7 to 11. It is sometimes known as purple-top vervain.
- Glandularia canadensis was once considered a member of the verbena genus but has now been recategorized. The 'Greystone Daphne' cultivar has lavender-pink flowers and grows to 8 inches with a sprawling habit. It is hardy in zones 5 to 8.
- V. tenuisecta (moss verbena) has delicate, lace-like foliage and grows to 5 or 6 inches. They bloom during late summer and early fall and are hardy in zones 7 to 9.