PL. —Cleome hasslerianaBotanical illustration — drop image
Cleome hassleriana

Spider Flower

SummerFall
2a11bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Peak bloom
Peak bloom
In bloom
Background

Spider flower earns its name from the long, spidery stamens that give each bloom a fireworks-like, wispy look, held in loose clusters atop tall, sturdy stems from midsummer until frost. Native to South America, it's a tender annual everywhere colder than a true tropical zone, but it grows fast from seed and reaches a bold, back-of-border height in a single season, making it a favorite vertical accent behind lower cottage-garden plantings.

Stems and leaf undersides carry small thorns, which is part of why deer and rabbits leave it alone. It self-seeds readily where happy, so let a few seed pods mature at the end of the season for volunteers the following year, or deadhead to limit spread. Once established it's quite drought tolerant and blooms right through summer heat with no deadheading required, though removing spent flower clusters tidies the plant and can extend the display.

Good companions
Care guide
SunFull sun
WaterModerate; drought tolerant once established
SoilWell-drained, average fertility
Spacing12–18 in
Height4–5 ft
Zone2a – 11b
Direct sow
Seasonal tasks
spring
sowDirect sow after last frost once soil has warmed, or start indoors 4–6 weeks earlier; seed needs light to germinate, so press onto the soil surface without covering.
summer
watchWatch for thorns on stems and leaf undersides when handling or weeding nearby.
cutRemove spent flower clusters to tidy the plant and extend bloom; leave a few pods to mature for self-seeding.
watchEstablished plants are drought tolerant and bloom through summer heat with little supplemental water.
fall
watchEnjoy continuous spidery blooms right up until frost.
Pests

Aphids

Aphididae
Symptoms

Clusters of small soft insects on new growth and flower buds.

Treatment

Knock off with a strong jet of water. Ladybirds and lacewings are natural predators. Insecticidal soap as last resort.