Ornamental · Verbenaceae
Verbena
Verbena canadensis
With generous sun and soil that sheds water, verbena dresses a border in uninterrupted color from the first warm days to the last.
Full sun
Every 5–7 days
USDA 6–10
8–18 in · 20–46 cm
Overview
Verbena has a way of carrying a garden through the long middle of the year, holding its color while other plants come and go. Rose verbena is a low, spreading perennial native to North America, and it threads clusters of bright flowers along a border from late spring into fall. It settles into a sunny bed, a gravel edge, or the rim of a container with the kind of easy grace that suits a relaxed, well-lived garden.
As a genus it ranges from low groundcovers to the tall, wiry Verbena bonariensis, and each one asks for the same warm, open, fast-draining setting. Because the flowers keep bees and butterflies moving all season, a drift of verbena reads as both a color note and a piece of a living, working garden. Many of the garden types are short-lived perennials, which makes them the easy pieces to refresh as a planting scheme shifts from one year to the next.
Verbena rewards a light touch, so long as the setting suits it. Placed in strong sun where water drains away, it holds its bloom through the season with barely any attention. Tucked into shade or heavy, damp ground, though, its display gives way to mildew and rot.
Care
The short version: full sun and sharp drainage set the tone for everything else. Give it about an inch of water a week to keep the color going, feed a couple of times through the season, and deadhead or shear it back to keep it in flower.
Light
Verbena wants full sun, the more the better, and it flowers hardest through a long, bright day. It will accept a little afternoon shade, but too much thins the bloom and leaves the door open to mildew, so give it the most open, sunlit spot in the garden.
Water
Once established, verbena is drought tolerant and takes a dry spell in stride, though it flowers best on 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. Containers dry out faster, so keep a closer eye on those.
Soil
Give it well-drained sandy or loamy soil, since wet feet are the one thing verbena will not forgive. It takes poor, rocky ground in stride and copes across a wide pH range of 6.0 to 8.0, but a soggy, poorly drained spot will rot it.
Humidity
Ordinary outdoor air suits it, so humidity is nothing to manage. What counts far more is airflow, since still, close 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 a trim. Verbena is no heavy feeder, and the extra really tells only on very sandy soils.
Pruning
Pinch the tips at planting for a fuller shape, and deadhead through the season to keep the flowers coming. When bloom slows in midsummer, shear the plant back by about a quarter, then water and feed it lightly, and the color returns in 2 to 3 weeks. Trim only lightly in fall and save hard pruning for spring, since a deep fall cut can cost the plant its cold hardiness.
Size & spacing
Rose verbena keeps low, standing 8 to 18 inches (20 to 46 cm) tall and spreading 12 to 24 inches (30 to 61 cm) wide. Set each plant to that full spread so air moves through and the spreading habit knits a bed together.
When to plant
Verbena keeps to warm weather and will not stand a frost, so let the cold pass before it takes its place outside. Start seed indoors in late winter or set transplants out once the soil has warmed, and the flowers hold from spring through fall to the close of the season.
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 of what troubles verbena traces to a setting that is too shaded or too wet. A glance over the leaves, flowers, and base of the plant, caught early, usually restores it with a simple change of place or routine. Find the match below, then act before it spreads.
Stems slumping and softening at the soil line where water lingers
A plant that flags while the soil stays wet is telling you about root rot from Pythium or Rhizoctonia, or southern bacterial wilt taking hold in ground that never drains. There is no reviving one this far along, so lift it out and dispose of it. Set the drainage right, then bring in fresh, healthy plants for a spot where water no longer lingers.
Fix:
- Improve drainage and stop overwatering
- Remove and discard affected plants
- Replant healthy stock in well-drained soil
A chalky white cast dulling the foliage
A chalky white haze over the leaves is powdery mildew, a fungus that creeps in wherever a planting sits shaded, packed tight, or parched. The remedy is a sunnier, more open spot with air on the move, and watering low at the roots rather than across the foliage. Clearing away the worst-marked leaves keeps a bed looking its best while it recovers.
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
Foliage losing its color to fine speckling and gossamer webs
A long, dry heat wave tends to usher in spider mites, and they settle on the plants left thirstiest. A firm rinse of water sends them packing, and steady soil moisture removes the stress that invited them in the first place. When they refuse to leave, insecticidal soap or horticultural oil closes the matter.
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
Blossoms fading to brown beneath a veil of gray mold
Spells of damp, close weather bring on botrytis blight, which browns the blooms and dresses them in a soft gray fuzz. Lifting away the spoiled flowers and the litter beneath them, and staying on top of deadheading, keeps faded petals from sitting and turning. Give the planting room to breathe and dry foliage, and it stays contained.
Fix:
- Remove and discard affected flowers and debris
- Improve air circulation and reduce overhead moisture
- Deadhead spent blooms promptly
Toxicity
Reassuring news for a home with pets or children: garden verbena is safe. The ASPCA does not list the genus Verbena as toxic to cats, dogs, or horses, so a stray nibble is no cause for alarm. Take care only not to confuse it with lemon verbena or lantana, the so-called shrub verbena, which are separate and toxic plants.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
A household cat can wander the border in peace, since the ASPCA does not list garden verbena as toxic. A curious nibble will do no harm.
Dogs None
Dogs can share the garden with verbena with ease, as it stays off the ASPCA toxic list. A large mouthful of any plant might bring a mild, brief stomach upset, and nothing beyond that.
Horses Safe
Horses grazing along the edge of a planting face no known danger from verbena.
Rabbits Safe
Rabbits may browse garden verbena in safety, as it holds no toxins that would affect them.
Livestock Safe
Cattle, goats, and sheep can share a pasture with verbena and have nothing to fear from it.
Birds Safe
Birds keep company with the plant unharmed, and pollinators drift to the flowers without any risk.
People Safe
Garden verbena is not toxic to people. It earns its place as an ornamental rather than a food crop, so there is no call to taste it.
Varieties
Verbena spans a wide sweep of habit, from trailing groundcovers to tall, airy stems that suit different corners of a garden. These are the types you will meet most often.
Homestead Purple
A trailing rose verbena with real staying power, spilling glowing purple flowers from late spring into fall while brushing off most abiotic disorders.
Verbena bonariensis (Purpletop vervain)
A tall, see-through species that lifts airy rose-violet clusters on slender stems to 2 to 5 feet, a transparent presence that has earned it the name verbena-on-a-stick.
Verbena × hybrida (Garden verbena)
The bedding hybrids in pink, purple, red, and white, grown by most gardeners as warm-season annuals.
How to propagate
Verbena is a generous plant to increase, whether you root a cutting to hold on to a favorite or raise a fresh batch from seed.
Stem cuttingsEasy
Take softwood cuttings during the growing season · Roots in about 2 to 4 weeks
Softwood cuttings taken through the growing season root in about 2 to 4 weeks. It is the dependable route for holding a named cultivar true to its parent, since seed will not copy it faithfully.
SeedEasy
Start indoors 6 to 8 weeks before last frost or direct sow after last frost · Germinates and blooms the first season
Seed started indoors 6 to 8 weeks before the last frost, or scattered into warm ground once frost has passed, flowers in the same season. The species types self-sow with ease, and bonariensis reseeds so freely it tends to return of its own accord.
Myths
No verbena belongs in a home with animals, since the whole tribe is poisonous.
Garden verbena in the genus Verbena never appears on the ASPCA toxic plant list. The confusion stems from lemon verbena (Aloysia) and lantana (shrub verbena), two separate plants that the ASPCA does flag for dogs and cats. The true Verbena in your bed is safe.
A verbena planting is an enduring perennial investment in any climate.
Most garden verbenas are short-lived perennials, better refreshed every two or three years. Where the winters run cold they do not last at all, so gardeners in those regions grow them as annuals.