Bulb · Iridaceae
Montbretia
Crocosmia × crocosmiiflora
From a knobby corm rise arching sprays of fiery tubular flowers, scarlet and orange, that hummingbirds probe for nectar.
Full sun
Every 3–7 days
USDA 5–9
2–4 ft · 0.6–1.2 m
Overview
Crocosmia, the plant long sold as montbretia, is a summer-flowering perennial in the iris family that grows from a rounded, papery-skinned corm rather than a true bulb. Native to southern Africa, it sends up arching stems hung with slim tubular flowers in hot reds, oranges, and yellows from June into August. The leaves are stiff and sword-shaped, ribbed down their length and standing upright in a fan like a young iris, while the flowers march in two facing ranks along one side of each curving stem.
The plant is undemanding. Given full sun to light shade and soil that drains, the clump thickens on its own as the corms stack into short underground chains, each one knotted to the next beneath the fan of leaves. That same readiness to multiply runs strong in mild regions, where crocosmia spreads hard and has escaped into the wild along the US Pacific coast, so a dense clump sometimes needs splitting apart.
Those narrow, flared trumpets are built for hummingbirds, which slip their bills deep into the tube for nectar. The whole plant is safe around pets, children, and grazing animals. Where winters stay within zones 5 to 9 the corms sit out the cold underground and push up a fresh fan of blades each year.
Care
The short version: crocosmia wants full sun to light shade, soil that drains freely without baking dry, its rounded corms set a few inches deep in spring, and the clump split every few years so the arching, flower-laden stems keep coming.
Light
Crocosmia colors up best in full sun, though it takes partial sun or light shade in stride. The more sun the fan of blades catches, the stiffer the arching stems stand and the more trumpets they carry, so an open spot shows it off.
Water
The soil stays evenly moist through the season, since the plant resents drying out and the blades go limp when it does. It will not sit in wet ground either, where the corm turns soft and rots, so drainage matters. Water runs every 3 to 7 days in dry spells and eases off where the soil holds moisture.
Soil
Crocosmia roots into humus-rich, well-drained soil, and clay, loam, or sand all suit it as long as water moves through. It is easy about pH, thriving anywhere from 6.0 to 8.0, so most garden ground takes it without change.
Temperature
The plant withstands a wide swing, from about 28°F to 86°F (-2°C to 30°C). Heat barely marks the blades, but cold past the hardiness range bruises the corm tissue, which is why colder zones lift the corms before winter.
Humidity
Ordinary outdoor air keeps the blades crisp, so there is no humidity level to manage. The thing to watch is dry, baking heat, which stresses the foliage and lets spider mites stipple the leaves.
Feeding
A balanced general-purpose fertilizer goes on at planting and again in spring as the new blades push up. That is plenty, since crocosmia is no heavy feeder, and over-rich soil swells the leaves at the cost of the flower stems.
Pruning
Once the trumpets shrivel, the spent flower stems are cut back to where they meet the leaves. The sword blades stay until they yellow and die down on their own, since they keep feeding the corm, and then they are cut to the ground for the season.
Repotting
Crocosmia grows in the bed rather than a pot, and the corm chains pack the soil tight over time. The corm clumps are divided every 2 to 3 years to keep them vigorous, with congested clumps, thinner flowering, and smaller blooms showing it is due.
Size & spacing
A clump throws its arching stems 2 to 4 feet (61 to 122 cm) high and spreads its fan of blades 12 to 24 inches (30 to 61 cm) wide. The corms go about 6 inches apart so the fans knit into a continuous stand within a season or two.
When to plant
Crocosmia keeps a clear seasonal sequence you can watch unfold. The corms go into the ground in spring after the last frost, the sword leaves push up and fan out, and the flower stems arch over and open through midsummer, roughly June to August. In colder zones the corms are lifted and stored before hard freezes.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: Plant corms in spring after the last frost date, 3-5 inches deep and about 6 inches apart.
- Harvest: Summer bloom, roughly June to August.
Hardiness
USDA hardiness zones: 5–9
Temperature: down to -29°C
Troubleshooting
Crocosmia stays healthy with little effort, so trouble is uncommon. What does go wrong shows on the blades or down at the corm, the parts most exposed to mites, browsing, and wet soil. Match the look below to what you see and step in early.
Soft, mushy corms and no blades pushing up
Corm rot turns the corm soft and discolored when the soil stays waterlogged or the cold sinks below what it can take, and then no blades push up. A lifted corm with mushy, off-color tissue confirms it. Better drainage fixes the main cause, and in zones colder than 5 the corms get a heavy winter mulch or are dug and stored dry like gladiolus.
Fix:
- Improve drainage and avoid standing water
- In cold zones, lift and store corms dry over winter or apply winter mulch
Stippled, bronzing blades veiled in fine webbing
Blades gone speckled and bronzed under a haze of fine webbing show spider mites, which build up fast in hot, dry spells. A strong jet of water knocks them off the leaf undersides, and moist soil with shelter from dry wind keeps them from returning. Insecticidal soap or horticultural oil clears the stubborn cases.
Fix:
- Spray foliage with a strong jet of water to dislodge mites
- Improve air moisture and avoid drought stress
- Apply insecticidal soap or horticultural oil as needed
Chewed-off blades and stems that never flower
Sword leaves cropped to clean, blunt cuts near the ground with no flower stems point to rabbits, confirmed by the grazed blades and droppings nearby. The damage is mechanical, not a disease. A wire cage or fence around the clump is the surest fix where rabbit pressure runs high.
Fix:
- Protect plants with fencing or wire cages
- Use repellents where appropriate
Toxicity
Crocosmia is not toxic. No reputable source flags any part of it, from the sword leaves to the tubular flowers to the corm, as poisonous, and it is grown as a hummingbird plant in part because it is safe to keep around. Wash your hands after handling the corms, the same plain habit you would keep with any garden plant.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Cats are unharmed. One that bats at the blades or chews a leaf comes to no harm.
Dogs None
Dogs are safe around it. A nibble of the leaves or flowers causes no poisoning, though a big mouthful of any plant can briefly upset a sensitive stomach.
Horses Safe
Horses graze near a clump without trouble, since crocosmia carries no toxin known to harm them.
Rabbits Safe
Rabbits relish the sword leaves and take no harm from them, which is more a problem for the flowers than for the rabbit.
Livestock Safe
Cattle, goats, and sheep browse it without poisoning risk, since the plant is not listed among forage hazards.
Birds Safe
Birds are safe around it. Hummingbirds in particular slip into the tubular flowers for nectar, which is part of why gardeners grow it.
People Safe
People face no reported toxicity. Wash your hands after handling the corms, the same routine you would follow with any garden plant.
Generally considered safe to handle; wash hands after gardening as a routine precaution.
Varieties
A short list of named cultivars covers most of what is sold, set apart mainly by the color of the trumpets and when they open. These are the ones worth knowing by sight.
Lucifer
Lucifer, an Alan Bloom hybrid, hangs vivid scarlet-red tubular flowers along its arching stems, and it ranks among the hardiest and most popular.
Emily McKenzie
Emily McKenzie carries large orange flowers stained with mahogany-red throats and opens later in the summer than most.
Solfatare
Solfatare sets soft apricot-yellow flowers above unusual bronze-tinted foliage.
Star of the East
Star of the East shows off large, soft orange blooms.
How to propagate
Crocosmia all but multiplies itself underground, so a second batch is rarely needed. Splitting the corm chains apart is the fast, dependable route, while seed gathered from the dry capsules is slower and less certain.
DivisionEasy
Early spring before new growth begins. · One growing season; flowering typically the same or following summer.
Division is the easy, reliable way to make more crocosmia. The congested corm clumps are lifted in early spring before the blades push up and pulled apart, which is done every 2 to 3 years to keep the plants vigorous. The divisions settle in within a season and often flower that same or the following summer.
Bulbs & cormsEasy
Spring, after the last frost. · One growing season.
Each corm stacks a short chain of offsets, one knotted above the last, that can be pulled apart and grown on. In spring after the frost, the offset corms are separated and replanted 3 to 5 inches deep and about 6 inches apart. They root and establish over a single growing season.
SeedModerate
Collect ripe seed from capsules; sow when available. · Two or more seasons to reach flowering size; some seed may not be viable.
Seed is the slower, less certain route. Ripe seed is shaken from the dry capsules and sown when available, but the seedlings take two or more seasons to reach flowering size. Those from hybrids rarely come true to the parent, and some seed is not viable.
Myths
Crocosmia corms are true bulbs like tulips and must be replanted every year.
Crocosmia grows from corms, solid and rounded under a papery skin, not the layered true bulb of a tulip, and that changes its care. In zones 5 to 9 the corms stay in the ground and naturalize, sending up fresh fans of blades year after year. Lifting and storage are needed only in colder zones, the same as with gladiolus.