Ornamental · Verbenaceae
Verbena
Verbena canadensis
Give it full sun and sharp drainage, and verbena keeps the color coming from spring right through fall.
Full sun
Every 5–7 days
USDA 6–10
8–18 in · 20–46 cm
Overview
Verbena earns its place with months of bloom on tough, easygoing plants. Rose verbena is a low, spreading perennial native to North America, and it carries clusters of bright flowers from late spring well into fall. It asks for little once it settles in, which is why it turns up in beds, borders, and trailing over the edge of a pot.
The genus runs from low groundcovers to the tall, wiry Verbena bonariensis, and most of them share the same loves: heat, sun, and soil that drains fast. They pull in bees and butterflies all season, so a patch of verbena does double duty as color and a pollinator stop. Many of the garden types are short-lived perennials, which means they shine for a couple of years and are easily replaced.
Verbena rewards a hands-off gardener as long as you get the basics right. Plant it where the sun is strong and the water never sits, and it will keep flowering with hardly any fuss. Crowd it into shade or damp ground, though, and you trade those flowers for mildew and rot.
Care
The short version: full sun and sharp drainage above all else. Water about an inch a week to keep the blooms coming, feed a couple of times in the growing season, and deadhead or shear it back to keep it flowering.
Light
Verbena wants full sun, the more the better, and it flowers hardest with a long day of direct light. It will take a little afternoon shade, but too much shade thins the blooms and opens the door to mildew.
Water
Once it's established, verbena is drought tolerant and shrugs off a dry spell, but it blooms best with about an inch of water a week. Water deeply once a week when rain falls short, always at the base rather than over the leaves, and never let the soil stay soggy. Plants in pots dry out faster and need a closer eye.
Soil
Give it well-drained sandy or loamy soil, the one thing verbena won't forgive is wet feet. It handles poor and rocky ground without complaint, and it copes across a wide pH range of 6.0 to 8.0, but a soggy, poorly drained spot will rot it.
Humidity
Plain outdoor air suits it, so there's no humidity to fuss over. What matters far more is airflow, since still, muggy conditions are where mildew and botrytis get their start.
Feeding
Feed with a complete fertilizer such as 16-4-8 in mid to late spring, then again after you trim the plant back. Verbena isn't greedy, and the extra feeding really only pays off in very sandy soils.
Pruning
Pinch the tips at planting for a bushier plant, and deadhead through the season to keep the flowers coming. When bloom slows in midsummer, shear the whole plant back by about a quarter, then water and feed it lightly and the flowers return in 2 to 3 weeks. Go easy in fall and save hard pruning for spring, since a deep fall cut can cost the plant its cold hardiness.
Size & spacing
Rose verbena stays low, running 8 to 18 inches (20 to 46 cm) tall, and it spreads 12 to 24 inches (30 to 61 cm) wide. Give each plant that full spread so air moves through and the spreading habit can fill in.
When to plant
Verbena is a warm-weather plant that won't take a frost. Start seed indoors in late winter or set transplants out once the cold has passed and the soil has warmed, and the flowers carry on from spring through fall until the season ends.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Start seed indoors 6 to 8 weeks before the last spring frost
- Plant: Set plants out after the last spring frost once soil has warmed
- Harvest: Blooms spring through fall (April to September in North Carolina)
Hardiness
USDA hardiness zones: 6–10
Temperature: down to -23°C
Troubleshooting
Most verbena trouble traces back to too much shade or too much water. Catch it early on the leaves, flowers, or at the base of the plant and a quick change usually turns things around. Match what you see below, then act before it spreads.
Wilting and rot at the base in soggy ground
When a plant wilts even though the soil is wet, suspect root rot from Pythium or Rhizoctonia, or southern bacterial wilt taking hold in waterlogged ground. There's no saving an affected plant, so pull it and bin it. Fix the drainage first, then replant healthy stock where water never pools.
Fix:
- Improve drainage and stop overwatering
- Remove and discard affected plants
- Replant healthy stock in well-drained soil
White powdery coating on leaves and stems
This is powdery mildew, a fungus that settles in when plants sit in shade, crowd each other, or run dry. Open the planting up to more sun and moving air, and water at the base rather than over the leaves. Strip off the worst-coated foliage to slow it down.
Fix:
- Move or thin plants to improve sun and air flow
- Avoid overhead watering and water at the base
- Remove and discard severely affected foliage
Speckled, yellowing leaves with faint webbing
Hot, dry weather brings out spider mites, and they hit thirsty plants first. Blast the foliage with a hard spray of water and keep the soil from drying out, since a stressed plant is what draws them. If they hang on, treat with insecticidal soap or horticultural oil.
Fix:
- Rinse foliage with a strong spray of water
- Keep plants adequately watered to reduce stress
- Treat persistent infestations with insecticidal soap or horticultural oil
Browning flowers under a gray fuzzy mold
Damp, humid spells invite botrytis blight, which turns the blooms brown and coats them in gray fuzz. Pick off the spoiled flowers and any debris, and keep deadheading so spent petals don't sit and rot. More airflow and dry foliage keep it from spreading.
Fix:
- Remove and discard affected flowers and debris
- Improve air circulation and reduce overhead moisture
- Deadhead spent blooms promptly
Toxicity
Good news for pet owners and parents: garden verbena is safe. The ASPCA does not list the genus Verbena as toxic to cats, dogs, or horses, so a stray nibble is nothing to panic over. Just don't confuse it with lemon verbena or lantana, the so-called shrub verbena, which are separate plants that are toxic.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Garden verbena is safe for cats, and the ASPCA does not list it as toxic. A curious nibble won't poison them.
Dogs None
Dogs can be around verbena without worry. It's off the ASPCA toxic list, though a big mouthful of any plant may pass a mild stomach upset.
Horses Safe
Verbena poses no known danger to horses grazing nearby.
Rabbits Safe
Rabbits can browse garden verbena safely, since it carries no toxins that affect them.
Livestock Safe
Cattle, goats, and sheep can share a pasture with verbena with nothing to fear from it.
Birds Safe
Birds are fine around the plant, and pollinators visit the flowers without any harm.
People Safe
Garden verbena is not toxic to people. Just remember it's an ornamental, not a food crop, so there's no reason to eat it.
Varieties
Verbena covers a lot of ground, from trailing groundcovers to tall, airy stems. These are the types you'll meet most often.
Homestead Purple
A vigorous trailing rose verbena that pours out glowing purple flowers from late spring until fall and shrugs off most abiotic disorders.
Verbena bonariensis (Purpletop vervain)
A tall, see-through species that reaches 2 to 5 feet on slender stems topped with airy rose-violet clusters, which earns it the name verbena-on-a-stick.
Verbena × hybrida (Garden verbena)
The bedding hybrids in pink, purple, red, and white that most gardeners grow as warm-season annuals.
How to propagate
Verbena is easy to multiply, whether you root a cutting to copy a favorite cultivar or let it grow from seed.
Stem cuttingsEasy
Take softwood cuttings during the growing season · Roots in about 2 to 4 weeks
Take softwood cuttings during the growing season and they root in about 2 to 4 weeks. This is the usual way to keep named cultivars true to type, since seed won't reliably copy the parent.
SeedEasy
Start indoors 6 to 8 weeks before last frost or direct sow after last frost · Germinates and blooms the first season
Start seed indoors 6 to 8 weeks before your last frost, or sow it straight into warm ground once frost has passed, and it blooms the same season. The species types self-sow with ease, and bonariensis reseeds heavily enough to come back on its own.
Myths
Every verbena is dangerous to pets because verbena is toxic.
Garden verbena in the genus Verbena isn't on the ASPCA toxic plant list at all. The mix-up comes from lemon verbena (Aloysia) and lantana (shrub verbena), two separate plants the ASPCA does flag for dogs and cats. The true Verbena in your bed is safe.
Verbena is a reliable, long-lived perennial everywhere.
Most garden verbenas are short-lived perennials that are best replaced after two or three years. Where winters turn cold they don't survive at all, so gardeners there grow them as annuals.