Flower Garden · Seed to Bloom

How to grow cleome

Grow cleome for airy spider-like flower clusters, strong vertical structure, and nonstop warm-season color that draws pollinators.

Start warm or direct sowGive plants roomDeadhead for a tidy display
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Botanical illustration of pink white and lavender cleome flowers
Botanical nameCleome hasslerianaSpider flower
Sow depth⅛ inchCover lightly
Germination7–14 daysWarm days, cool nights
Spacing18–24 inchesAiry branching habit
Height3–5 feetVariety dependent

Flower profile

Add height without making the border feel heavy.

Cleome produces tall stems topped with open clusters of long-stamened blooms. Its airy habit fits cottage borders, pollinator plantings, and the back of sunny annual beds.

Warm days and cooler nights help germinationIf indoor germination is uneven, provide warmth by day and a modest nighttime temperature drop while keeping the mix evenly moist.

cleome at a glance

From seed to a productive flower display

01Sow4–6 weeks early02Sprout7–14 days03HardenAfter frost04BranchWarm growth05BudEarly summer06BloomUntil frost

Planting

Sow shallowly and transplant before roots crowd.

Cleome dislikes prolonged root disturbance. Start in individual cells or direct sow after frost where summers are long.

01

Cover about ⅛ inch

Sow into moist mix and cover lightly; do not bury the fine seed deeply.

02

Give seedlings bright light

Thin or pot on promptly so young plants stay compact and upright.

03

Space for airflow

Harden after frost and set 18–24 inches apart in a sunny, drained bed.

Ongoing care

Keep plants healthy and flowers productive

Maximize sun

Full sun keeps stems sturdy and flowering generous.

Water deeply while establishing

Once rooted, water when the upper soil begins to dry rather than keeping it soggy.

Feed lightly

Moderate fertility supports bloom without producing soft stems.

Deadhead or allow seed

Remove spent heads for a neater display, or leave a few if self-sowing is welcome.

Season checkpoints

Follow the plant’s visible progress.

7–14 days

Seedlings emerge

4–6 weeks

Plants fill cells

Early summer

First clusters open

Until frost

New blooms continue

Cutting and display

Cut when the lower flowers are opening.

For arrangements, cut stems when several lower florets have opened and the upper buds still show color. Condition immediately in clean water.

  1. Cut in the cool morning.
  2. Strip foliage below the waterline.
  3. Handle prickly stems with gloves if needed.

Urban Farmer selections

Grow an airy spider-flower display

Spider Flower Mix product imageTall annual · mixed colorsSpider Flower MixPink, white, and lavender spider-like blooms on tall branching stems.Checking availability…Shop Spider Flower Mix →

Questions flower gardeners ask

Cleome growing FAQ

When should cleome seed be started?

Start indoors 4–6 weeks before the last frost or direct sow after frost.

How deep should cleome be planted?

Cover seed lightly, about ⅛ inch.

How long does germination take?

Expect roughly 7–14 days under suitable conditions.

Why is germination uneven?

A day-to-night temperature change can improve germination.

How far apart should plants be?

Space about 18–24 inches apart.

Does cleome need full sun?

Yes, full sun gives the strongest stems and best bloom.

Does cleome need staking?

Most plants stand well, but exposed sites may benefit from discreet support.

Should cleome be deadheaded?

Deadhead for neatness and continued bloom, or leave seed heads for self-sowing.

Is cleome good for pollinators?

Its nectar-rich flowers attract bees, butterflies, and other visitors.

Can cleome grow in containers?

Yes, use a large stable container for its height and root system.

Ready to plant?

Bring airy height and pollinator color to the summer border.

Shop cleome →