Verbena can rock any spot in the garden during the hottest days of summer!
From the National Garden Bureau
Overview and History
Gardeners know verbenas for their ability to withstand the pressure of hot, dry conditions. Luckily for all of us, there are many new hybrids that have been bred just for this job!
The verbena belongs to the Verbenaceae family, which contains some 800 species in 32 genera. Many of them are native to the Americas and Asia. This family is characterized by clumps or spikes of flowers on heat-loving herbs, shrubs, trees, or vines. Other notable members of this family include common verveine (Verbena officinalis), lemon verbena (Aloysia spp.), lantana (Lantana spp.), porterweed (Stachytarpheta spp.), tall verbena (Verbena bonariensis) and sandpaper vine (Petrea volubilis). For purposes of this article, we are focusing only on the annual types commonly called garden verbenas (Verbena × hybrida, now Glandularia × hybrida).
While common verbena served as a medicinal herb and holy plant in ancient Egyptian, Roman, and Greek civilizations, we prize the verbenas we grow today for their ornamental value. There are many varied types and habits, including upright and tall, as well as mounded and trailing. Some verbenas make great ground covers as well.
Basic Types and Variety Names
Most verbenas on the market are hybrid cultivars bred to have a winning combination of traits coming from many different verbena species. These hybrid varieties generally have larger flowers, brighter and more saturated colors, and larger, more weather-tolerant leaves than their species relatives. Hybridizers also bred into them more heat, water-stress, and disease tolerance. Especially tolerance against powdery mildew, a real problem with older varieties. These modern cultivars are often available in series. Each series includes verbenas with similar characteristics, but different flower colors.
Their leaves are often dense and hairy. Their flowers are small with five petals and set in dense clusters. Typical colors include shades of blue and purple, but they can also be found in white and pink shades. Environmental factors can determine the flowering time and size of a verbena plant. As temperatures rise, some plants may go out of color and stay a bit green until a cool-off. Others are bred to withstand heat and humidity with flowers and bulky growth that carry on non-stop through the growing season.
Pollinators love verbenas! Hummingbirds, butterflies, and moths are all frequent visitors. Bees of all types love verbena, too.
Verbena Varieties to Look For:
- The Aztec Series has big clusters of vibrant flowers that provide an eye-catching display in containers, beds, and hanging baskets. Free-flowering through heat and humidity on a mounding trailing plant.
- The Empress Series includes both trailing and semi-trailing types of verbena with eye-catching flower colors that stay a compact 8–10 in (20–25 cm) tall but can spread up to 18 in (45 cm) wide.
- EnduraScape™ Pink Bicolor is a 2017 All-America Selections winner. This vigorous and spreading, long-flowering plant can be considered a hardy annual (zone 7) since it thrives in the heat and can take some chilling temperatures as well.
- Firehouse™ Purple Fizz is a top performer at many university flower trials. This medium-vigor purple and white bicolor verbena has a beautiful mounded habit perfect for hanging baskets and landscapes. This variety, and the others in the Firehouse series, have superior powdery mildew tolerance and prolonged summer flowering.
- The Twister series is popular because of its unique tricolor blooms and long-flowering periods.
- Lanai is a series with distinct color patterns that remain strong and stable (and powdery mildew resistant) throughout the growing season. Lanais come in three types: regular, compact, and upright.
- Look to the Obsession series for bold colors and a twister pattern. They’re one of the few verbenas still available from seed.
- Superbena® Imperial Blue™ is a new-to-market variety with an attractive and truly unique blue color on large flowers. This Superbena boasts exceptional branching on a tidy, manageable habit. It’s tough as nails and will continue blooming late through the summer.
- The Beats™ series is a fun new compact size of verbena. Purple+White is a bicolor bloomer that is a great option for small patio pots and tabletop bowls, as it will keep its eye-catching mound of color all summer long.
- Temari® Trailing is a range of broad-leaved verbenas which produce vigorous branches that quickly form mounds of color via large bold blooms.
- Tapien® is a fine leaved series of verbenas known for their spreading habit. They offer good cold and heat tolerance and mildew resistance. Tapien makes an excellent ground cover plant and is constantly in bloom.
- Tuscany, also from seed, has an upright habit perfect for small or medium-sized containers. Big blooms and sunny colors add a bright interest to the garden.
- Cake Pops™ is fun and functional. These verbenas have a cute globular flower shape and will not flush. Cake Pops are available in two pleasing soft colors: Pink and Purple.
- Homestead Purple has been around for over two decades. It’s known best for its determination to continuously flower through summer, and it’s hardy enough to grow as a perennial in USDA hardiness zones 7–11. It makes an excellent drought-tolerant groundcover. Homestead Hot Pink is a new color and promises to deliver the same performance in a bright, new hue.
Verbena Home Gardening Tips
While verbena seed is available, many of the newer varieties that have the desirable traits are vegetatively propagated. They can be found as young plants at your local garden retailer in the spring.
Verbena looks their best when their soil is kept moist, but not wet as they don’t like soggy feet. If the growing medium dries out too much, it can cause “flushing.” Flushing is commonly known as cycling out of color. It occurs when the plant loses blooms, but remains green and leafy.
Verbena plants should be placed in sunny locations, aiming for 6+ hours of direct light. Most species perform well in the ground or landscape. They can also be displayed in hanging baskets and patio containers. The compact-growing verbena work best in pots. They don’t have the root vigor necessary for garden bed applications. For prolonged flowering, deadhead verbena by cutting or pulling off spent flower heads.
Powdery Mildew (PM) is an unfortunate occurrence on some verbenas. The best practice is to look for newer varieties that have a built-in resistance. If PM does appear (it will present as white patches of fluffy fungus on leaves or stem) treat with a neem spray or your favorite fungicide. Catching PM early is the best solution, as this disease can spread quickly. Also, its fungus blocks sunlight to the plant’s nutrition system, making the plant unable to produce food. That will ultimately cause the plant to perish.
Gardening with verbenas can elevate your landscape design and add texture and color to your patio containers. You’ll appreciate their colorful branches and how well they play with other flowers in your garden. Whether you live in northern climates and enjoy them for a single summer, or watch them return year after year in warm, southern climes, verbena is an excellent choice for plant lovers of all levels of garden abilities.
This article was adapted from a fact sheet written for the National Garden Bureau and provided as an educational service. Unless otherwise mentioned, photos are courtesy of the National Garden Bureau. Purchase verbenas at NGB Member Online Stores and at your local garden retailer. Please consider NGB member companies as authoritative sources for information.