Gardeners looking for a flowering annual with a long blooming time and an ability to attract butterflies should consider the reliable verbena. This versatile plant comes in more than 250 perennial and annual varieties that range from vivid trailing plants with copious blooms and plants in hanging baskets to six-foot-tall cottage garden accent plants. Popular in the ancient world for its healing properties and, today, as an essential oil, verbena has long been associated with divinity and the supernatural.
- Botanical Name: Family Verbenaceae
- Common Name: Verbena, vervain, herb of the cross, holywort
- Plant Type: Many types, annuals and perennials
- Mature Size: Varies from six inches tall to six feet tall
- Sun Exposure: Full sun
- Soil Type: Well-draining, tolerates most soil types
- Soil pH: Acidic
- Bloom Time: Summer, fall
- Flower Color: White, pink, red, lavender, blue, and purple
- Hardiness Zones: 5-11
- Native Area: Americas and Asia
How to Grow Verbena Plants
Because there are so many types of plants in the Verbena genus, gardeners may be confused about which are perennial and which are annual. Size can vary greatly between varieties, ranging from six-inch groundcovers to six-foot plants. No matter the species put this tough specimen in a place where it will get 8 to 10 hours of sun each day. The verbena flower is not particular about soil, except that it must be well-draining.
After choosing a sunny area of your landscape, make sure your soil has adequate drainage for your verbenas. Heavy clay will lead to root rot, so dig in several shovelfuls of compost or leaf mold to lighten your soil.
Keep plants evenly moist until established, when they can tolerate some dry spells. Verbena is somewhat drought tolerant, and it certainly does not do well in boggy conditions, but you must not underwater it either. Soggy plants will succumb to botrytis blight, but drought-stressed plants will attract spider mites. Water verbena as you might your lawn, with an inch of rain or irrigation each week.
Temperature and Humidity
Annual verbena may decline quickly when summer weather turns hot and humid. In warmer climates, perennial verbenas may grow better than the annual form.
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.
Propagating Verbena Plants
You can start verbena from seed and from cuttings, or for quicker results start with transplants. If growing from seed, keep seed covered and moist until germination occurs, which takes about three weeks.
All verbenas benefit greatly from regular deadheading. This not only removes the seed heads that signal the plant to rest but also helps to keep sprawling plants in their place in your landscape. If you have a large planting of low-growing verbena, you can accomplish this quickly with a string trimmer.
Verbena is vulnerable to a range of houseplant pests. Some, such as leafminers, are just an annoyance, but others (aphids, spider mites, scale, mealybugs, whiteflies, and thrips) can wreak havoc on your plants if you don't take steps to control the infestation. If your verbenas show signs of insect pest infestation, you will have to weigh your desire to use an insecticide with your desire to nourish your butterfly population. If you do decide to spray, remember that plants grown in shade or heavy soil will continue to attract pests. Insecticide does not fix poor gardening practices.
Use trailing varieties in hanging baskets, containers, and at the edge of flower borders. Plant trailing verbena with complementary flowers that appreciate the same growing conditions, like million bells, penta flowers, and marigolds.
All types of verbena are welcome in the butterfly garden. Tall varieties belong in the cottage garden, naturalized meadow, or back of the border. A companion planting of bronze fennel with tall verbena is the perfect way to support a butterfly's life cycle, as swallowtail butterflies like to feed on the bronze fennel foliage, and the adults are nourished by the nectar-rich verbena flowers.
Verbena is both a deer and rabbit resistant plant, so take advantage of this by planting at the edge of your property where animals frequently browse.
Varieties of Verbena Plants
The perennial type, Verbena canadensis, tend to fade away after a few seasons. Brazilian verbena plants may self-sow freely, fooling the gardener into thinking that the plant has returned as a perennial. And then there is the "Superbina’" series, which may be a short-lived perennial in zones 7 or 8.
Verbena plants are available in a variety of heights and a range of colors that cover the pink, red, and purple spectrum. All of the plants bear clusters of shallow flowers that butterflies find irresistible. Many plants have lacy or needle-like foliage. Verbena plants have a rich history in herbal medicine and are still used as a remedy for digestive ills and insomnia.
- Blue Vervain: The native Verbena hastata has a tall, airy habit with bluish-purple flowers.
- Bonariensis: The popular Brazilian species grows up to six feet tall and self-seeds freely. Grown as a perennial in zones 7 and warmer, it attracts butterflies in droves. Also, try the compact varietals for Bonariensis verbena: "Lollipop" and "Meteor Shower."
- Greystone Daphne: This plant has fragrant lilac-colored flowers on trailing plants.
- Homestead Purple: Popular in the garden world, this is a purple-flowering groundcover that performs throughout the growing season. It is a short-lived perennial in zones 6 and warmer.
- Lanai Royal Purple with Eye: This plant is bright purple with a contrasting white eye.
- Tapien series: Fine, needle-like foliage is the hallmark of this moss verbena.
- Texas Rose: A short-lived groundcover perennial, this cultivar bears reddish-pink flowers.