Ornamental · Ranunculaceae
Columbine
Aquilegia canadensis
Hand it dappled shade and moist, free-draining soil, and columbine answers with spurred spring flowers that hummingbirds chase.
Partial shade
Every 5–10 days
USDA 3–8
1–3 ft · 0.3–0.9 m
Overview
Columbine is a woodland perennial in the buttercup family, and the native Eastern red kind, Aquilegia canadensis, grows wild across much of eastern North America. Its nodding, spurred flowers dangle on thin stems above soft, blue-green foliage, and they pull in hummingbirds as the spring warms up. The look is delicate, but the plant is tougher than it appears.
This is an easygoing plant for partial shade, content at the edge of a border or in a woodland patch where taller plants throw a little cover. It rides out hard winters down to USDA zone 3 and pushes through summers up to zone 8. Columbine is short-lived as perennials go, but it sows itself so freely that a planting tends to renew on its own and drift into loose colonies.
Give it ground that holds moisture yet drains well, and most of the work is done. The flowers come in a wide spread of colors across the genus, from the red and yellow of the native species to the blues, whites, and pinks of the old European types. Let a few seedheads ripen and you will find new plants turning up nearby each season.
Care
The short version: partial shade and rich, moist, well-drained soil. Water to keep the ground evenly damp without letting it stay soggy, feed lightly in spring, and cut back tired foliage after bloom to tidy the plant and curb its self-seeding.
Light
Columbine does best in partial shade, the kind of dappled light it gets at a woodland edge. It will take full sun in cooler regions and tolerate partial sun, but in hot summers the deeper shade keeps it from scorching.
Water
Keep the soil evenly moist but never waterlogged, watering roughly every 5 to 10 days once you account for rain. An established plant shrugs off the odd dry spell, yet soggy ground through a hot summer invites crown rot, so let the surface dry a touch between waterings.
Soil
Plant in rich, well-drained loam worked with organic matter, though columbine adapts to sand or clay as long as the water moves through. It handles a wide pH band from 6.0 to 8.0, so most garden soil suits it without fuss.
Temperature
This is a cold-hardy perennial, comfortable across USDA zones 3 to 8 and weathering temperatures from -40°F to 90°F (-40°C to 32°C). The deep winter cold actually helps, since the seeds need a chill before they will sprout.
Humidity
Ordinary outdoor humidity is all it asks, so there is no figure to hit. Air movement matters more than the moisture in it, because still, crowded conditions are what let powdery mildew settle on the leaves.
Feeding
Columbine is a light feeder. A single balanced feed or a topdress of compost in spring carries it through the season, and piling on more fertilizer only draws aphids to the soft new growth.
Pruning
Cut the spent flower stems after bloom to coax a second flush and rein in the heavy self-seeding. If the foliage looks ragged by mid-summer, shear it to the ground and fresh leaves will follow.
Size & spacing
Plants reach 1 to 3 feet (30 to 91 cm) tall with a spread of 12 to 18 inches (30 to 46 cm). Give each one that much elbow room so air moves through the clump and mildew stays away.
When to plant
Columbine runs on the spring. Start seed indoors in late winter after a cold spell to break dormancy, or sow it straight into the ground in spring or fall. The spurred flowers open from March into May and hold for four to six weeks before the plant settles in for the summer.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter, 6 to 8 weeks before last frost; seeds benefit from cold stratification.
- Plant: Spring after last frost, or sow seed outdoors in fall.
- Harvest: Spring (March to May), with bloom lasting about four to six weeks.
Hardiness
USDA hardiness zones: 3–8
Temperature: down to -40°C
Troubleshooting
Columbine is an easy plant, and most of what goes wrong shows up on the leaves or at the base. Catch the early signs and a quick trim or a change in watering usually sets things right. Match what you are seeing below, then act.
Plant wilting and rotting at the base in summer
When the crown turns soft and brown and the whole plant flops in hot weather, you are looking at crown rot driven by soggy, airless soil. There is no saving an affected plant, so lift it out. Replant only after you have opened up the drainage, and ease off the water through the heat of summer.
Fix:
- Remove affected plants
- Improve soil drainage before replanting
Pale winding trails tunneling through the leaves
Those squiggly tracks are the work of leaf miner larvae feeding between the upper and lower leaf surfaces. The damage looks alarming but stays cosmetic, so the plant pulls through fine. Strip off the mined leaves, and cut the foliage to the ground after bloom to push out a clean flush of new growth.
Fix:
- Remove and destroy mined leaves
- Cut affected foliage to the ground after bloom to flush fresh growth
- Choose resistant species such as Aquilegia canadensis
Soft insects clustered on buds and new shoots
Tight colonies of green or black aphids crowd the tender tips and suck sap, which twists the new leaves and leaves a sticky film behind. Knock them off with a sharp jet of water, and reach for insecticidal soap only when the numbers get out of hand. Going easy on nitrogen feed keeps the lush, soft growth they love to a minimum.
Fix:
- Spray plants with a strong jet of water
- Apply insecticidal soap if populations are heavy
Dusty white film coating the leaves and stems
A whitish, talc-like dust on the foliage points to powdery mildew, a fungus that settles in where the air sits still and plants grow too close. Space your columbines so air moves freely through them, and clear out any infected leaves. Watering at the base rather than over the top keeps the foliage dry and far less inviting.
Fix:
- Improve air circulation by spacing plants
- Remove and destroy infected foliage
Toxicity
Columbine is only mildly toxic, and the showy flowers are low-risk. The trouble lies in the seeds and roots, which hold cardiogenic toxins and cyanogenic glycosides that can upset the stomach if eaten in quantity. Routine gardening calls for no special handling, but keep pets and children from making a meal of the seedpods.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Mild
A cat that nibbles the seeds or roots may drool, vomit, or get a loose stomach. The flowers and leaves are low-risk, and trouble shows up only when a fair amount goes down.
Dogs Mild
Most dogs walk away unharmed, though chewing the seeds or roots in quantity can bring on drooling and a brief bout of vomiting or diarrhea.
Horses Mild
Horses tend to leave columbine alone, and a stray mouthful does little. A large feed of the seed-bearing or root parts is the only thing likely to upset the gut.
Rabbits Mild
Keep rabbits off the seedpods and roots, where the cyanogenic compounds concentrate. A small graze on the foliage rarely causes more than a passing tummy ache.
Livestock Mild
Cattle, goats, and sheep usually avoid the plant, and poisoning is uncommon. Heavy grazing on the seeds or roots can still trigger mild digestive upset.
Birds Mild
The flowers draw hummingbirds to the nectar with no harm at all. The seeds carry the cyanogenic glycosides, so keep poultry from gorging on the ripe pods.
People Caution
Columbine is not a kitchen plant. The flowers are low-risk, but the seeds and roots hold cardiogenic toxins, so eating them in quantity can cause stomach upset and should be avoided, especially by children.
No special handling is needed for routine gardening; wash hands after extended contact and supervise pets and children around the seeds.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
Columbine ranges from a tough native wildflower to big, showy garden hybrids. These are the ones you are most likely to meet.
Aquilegia canadensis (Eastern red columbine)
This is the native species, carrying nodding red and yellow spurred flowers on wiry stems and shrugging off the leaf miner that plagues its relatives.
Aquilegia vulgaris (Granny's bonnet)
The old European columbine blooms in blue, violet, white, pink, or red, though it takes leaf miner damage far harder than the native plant does.
Aquilegia chrysantha (Golden columbine)
A southwestern species with long-spurred yellow flowers that handles heat better than most, but it rots at the crown fast in soil that drains poorly.
Aquilegia × hybrida (Hybrid columbine)
These garden hybrids show off the biggest, often bicolor long-spurred flowers in the widest range of colors, opening from mid-spring into early summer.
How to propagate
Columbine all but propagates itself, though you can lend a hand with saved seed or a careful division of an established clump.
SeedEasy
Sow indoors in late winter with cold stratification, or direct sow outdoors in spring or fall. · Seedlings typically flower in their second year.
Seed is the surest way to multiply columbine, and the plant does most of the work itself by self-seeding into loose colonies wherever conditions suit it. Start seed indoors in late winter after a spell of cold to break dormancy, or scatter it outdoors in spring or fall. Either way, expect the first flowers in the seedling's second year, since the plant spends its first season building a crown.
DivisionModerate
Early spring or fall. · One growing season; columbine has a deep taproot and resents disturbance, so divide carefully.
Division works in early spring or fall, but it is the harder road. Columbine sends down a deep taproot and sulks when disturbed, so lift and split the clump gently and get the pieces back in the ground straightaway. Given a single growing season to settle, a careful division will take, though seed stays the more reliable bet.
Myths
Columbine is deadly poisonous and should never be grown around pets or children.
The genus has low toxicity, and extension sources flag no serious poisoning problems for it. The seeds and roots do hold cyanogenic compounds, so a large mouthful of those parts can bring on mild stomach upset, but the plant is safe to grow with normal supervision and the flowers are low-risk.
Every columbine gets chewed to ribbons by leaf miner.
How badly a plant suffers comes down to which one you grow. The native Aquilegia canadensis stands up well to leaf miner, while hybrids and other species often take heavy damage, so picking a resistant species is the simplest fix.