Bulb · Iridaceae
Montbretia
Crocosmia × crocosmiiflora
Plant the corms once and crocosmia answers with arching sprays of fiery summer color that hummingbirds can't resist.
Full sun
Every 3–7 days
USDA 5–9
2–4 ft · 0.6–1.2 m
Overview
Crocosmia, often called montbretia, is a summer-flowering perennial from the iris family that grows from a corm rather than a true bulb. It came out of southern Africa and earned its place in gardens for the arching stems of tubular flowers in hot reds, oranges, and yellows that open from June into August. The sword-shaped leaves stand upright like a small iris, and the flowers line up along one side of each stem.
It asks for very little. Give it full sun to light shade and soil that drains well, and a clump will widen on its own, multiplying its corms in chains below ground. That same vigor is worth knowing about up front: in mild regions crocosmia spreads hard and has escaped into the wild along stretches of the US Pacific coast, so a clump can need reining in.
The flowers are a magnet for hummingbirds, and the whole plant is safe to have around pets, children, and grazing animals. Where winters stay within zones 5 to 9 the corms ride out the cold in the ground and come back stronger each year.
Care
The short version: full sun to light shade, soil that drains freely but never bakes dry, corms planted a few inches down in spring, and a clump lifted and divided every few years to keep the flowers coming.
Light
Crocosmia flowers best in full sun, though it takes partial sun or light shade in stride. The more sun it gets, the stronger the stems stand and the heavier the bloom, so give it an open spot if you can.
Water
Keep the soil evenly moist through the growing season, since the plant resents drying out. The catch is that it won't sit in wet ground, so drainage has to be good or the corms rot. Water every 3 to 7 days in dry spells, easing off where the soil holds moisture.
Soil
Plant in humus-rich, well-drained soil; clay, loam, and sand all work as long as water moves through. Crocosmia is easy about pH and runs happily anywhere from 6.0 to 8.0, so most garden beds suit it without any fuss.
Temperature
It handles a wide swing, from about 28°F to 86°F (-2°C to 30°C). Heat doesn't faze it, but the corms can take cold damage past their hardiness range, which is why colder zones lift them for winter.
Humidity
Ordinary outdoor air is all it needs, so there's no humidity target to hit. Dry, baking conditions are the real risk, since they invite spider mites onto stressed foliage.
Feeding
Feed with a balanced general-purpose fertilizer at planting, then again in spring as growth gets going. That seasonal nudge is plenty; crocosmia is no heavy feeder and over-rich soil pushes leaves at the expense of flowers.
Pruning
Once the blooms fade, cut the flower stems back to where they meet the leaves. Leave the foliage standing until it dies down on its own, because it's still feeding the corm, then cut it to the ground for the season.
Repotting
Crocosmia doesn't sit in pots so much as crowd itself in the bed. Divide the corm clumps every 2 to 3 years to keep them vigorous; congested clumps, weaker flowering, and smaller blooms are the plant's way of asking for it.
Size & spacing
A clump reaches 2 to 4 feet (61 to 122 cm) tall and spreads 12 to 24 inches (30 to 61 cm) wide. Set the corms about 6 inches apart at planting and they'll knit into a full stand within a season or two.
When to plant
Crocosmia runs on a simple seasonal clock. Plant the corms in spring once the last frost has passed, and the flowers follow through the heart of summer, roughly June to August. In colder zones, plan to lift and store the corms before hard freezes set in.
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 fuss, so trouble is the exception rather than the rule. The few problems that do crop up show on the leaves or down at the corm. Match what you see below and step in early.
Corms turn mushy and plants never come up
Corm rot sets in when the soil stays waterlogged or the cold dips below what the corms can take. Lift a few and check for soft, discolored tissue to be sure. Fix the drainage, and in zones colder than 5 either mulch heavily for winter or dig the corms and store them dry like gladiolus.
Fix:
- Improve drainage and avoid standing water
- In cold zones, lift and store corms dry over winter or apply winter mulch
Speckled, bronzing leaves laced with fine webbing
This is the work of spider mites, which move in fast during hot, dry spells. Blast the leaves with a strong jet of water to knock the mites loose, then keep the soil moist and the plant out of dry wind. Insecticidal soap or horticultural oil clears up 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
Grazed foliage and flowers that never appear
Rabbits are the usual culprits when the leaves get nibbled down and the blooms never come. Look for clean-cut foliage near the ground and droppings nearby to confirm it. 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
Good news for households with pets and small children: crocosmia is not toxic. No reputable source flags any part of it as poisonous, and it is grown as a hummingbird plant precisely because it's safe to have around. Wash your hands after handling the corms, the same simple habit you'd keep with any garden plant.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Nothing to worry about here. A cat that bats at the foliage or chews a leaf won't be harmed.
Dogs None
Safe around dogs. A curious 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 can graze near a clump without trouble, as crocosmia carries no toxin known to harm them.
Rabbits Safe
Rabbits actually relish the foliage and come to no harm from it, which is more a problem for your blooms than for the rabbit.
Livestock Safe
No poisoning risk for cattle, goats, or sheep that browse it; the plant is not listed among forage hazards.
Birds Safe
Birds are fine around it. Hummingbirds in particular flock to the tubular flowers for nectar, which is part of why gardeners grow it.
People Safe
No toxicity reported for people. Wash your hands after handling the corms, the same routine you'd follow with any garden plant.
Generally considered safe to handle; wash hands after gardening as a routine precaution.
Varieties
A handful of named cultivars cover most of what you'll find for sale, sorted mostly by flower color and bloom time. These are the ones worth knowing.
Lucifer
An Alan Bloom hybrid that throws showy scarlet-red tubular flowers along arching stems, and it ranks among the hardiest and most popular of the lot.
Emily McKenzie
It carries large orange flowers marked with mahogany-red throats and opens later in the summer than most.
Solfatare
This one pairs soft apricot-yellow flowers with unusual bronze-tinted foliage.
Star of the East
It stands out for its large, soft orange blooms.
How to propagate
Crocosmia all but multiplies itself, so most gardeners never buy a second batch. Dividing clumps is the fast, sure route, while seed is a slower gamble worth it only for the patient.
DivisionEasy
Early spring before new growth begins. · One growing season; flowering typically the same or following summer.
Division is the easy, reliable way to get more crocosmia. Lift the congested corm clumps in early spring before new growth starts and split them apart, doing this 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 builds a chain of offsets you can pull apart and grow on. In spring once the frost has passed, separate the offset corms and replant them 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.
Growing from seed is slower and less certain. Collect the ripe seed from the capsules and sow it when you have it, but expect two or more seasons before the plants reach flowering size. Seedlings from hybrids rarely come true to the parent, and some seed simply won't be viable.
Myths
Crocosmia corms are true bulbs like tulips and have to be replanted every year.
Crocosmia grows from corms, not true bulbs, and that changes how you treat it. In zones 5 to 9 the corms can stay in the ground and naturalize year after year. Only in colder zones do you need to lift and store them, the way you would gladiolus.