Distinctive and eye‑catching, Cleome spinosa earns its common name spider flower from its delicate blooms with dramatically long protruding stamens that spread outward like spider legs. This fast‑growing annual develops upright branching stems, bringing vertical height to summer flower beds without demanding constant hands‑on care. Blossoms unfurl in soft shades of pink, lavender and pure white, stacked along tall terminal racemes, delivering weeks upon weeks of continuous summer colour.
These flower seeds thrive under warm sunny weather, showing excellent heat tolerance throughout the hottest months. Plant them toward the rear of flower borders or scatter within cottage‑garden plantings, where their lofty stature creates soft layered depth. Nectar‑rich blossoms act as a powerful pollinator magnet, welcoming bees and butterflies to visit your garden space. Mature plants can reach 1‑1.5 meters tall; provide shelter from strong gusty wind, or add simple stakes to prevent tall stems from toppling over under heavy bloom weightRoyal Hort.... Well‑drained soil is essential; soggy waterlogged ground will trigger root rot, even though the plant can cope reasonably well with short dry spells once fully established.
Planting Instructions Soil Preparation Select a sunny sheltered location. Loose, fertile, well‑drained loam soil works best. Mix compost into heavy clay ground to improve drainage capacity. Avoid low‑lying spots where rainwater accumulates.
Seed Pre‑treatment Complete seeds can be sown directly. A short overnight soak in lukewarm water is optional, which helps speed up germination progress. No cold stratification is needed.
Sowing Method Start indoors 4‑6 weeks before last frost arrives, or direct‑sow outdoors once frost risk is fully gone. Cover seeds lightly with fine soil. Space individual plants 30‑40 cm apart to guarantee good air circulation around mature bushy growth.
Germination Condition Optimal germination temperature:20‑25°C. Seedlings emerge within 7‑15 days. Keep seedbed lightly moist, never water‑logged during sprouting phase.
Daily Maintenance Full sun brings maximum flowering output. Water at soil base, avoid wetting leaf surfaces. Stake tall stems in windy garden sites. Remove faded flower spikes if you wish to limit excessive self‑sowing. Watch for aphid infestations on tender young shoots.
Specification Plant Name: Cleome spinosa Botanical Name: Cleome spinosa Plant Type: Upright heat‑tolerant annual ornamental flower Bloom Feature: Spider‑shaped raceme blooms with long prominent stamens, pink‑lavender‑white tones Blooming & Fruiting Period: Mid‑summer to early autumn Germination Temperature:20‑25°C Growing Temperature:15‑30°C, strong heat resistance Light Requirement: Full sun, tolerates light partial shade Soil: Fertile loose well‑drained loam soil Planting Difficulty: Easy Core Features: Cleome spinosa seeds, spider flower seeds, tall vertical garden annual, pollinator‑attracting, heat‑resistant, ideal for cottage gardens and back‑border landscaping
FAQ Q1: Why is Cleome spinosa called spider flower? A1: Each bloom carries extremely long thin thread‑like stamens stretching far out from petals, creating a visual look similar to spider legs. Q2: Do spider flower plants need staking? A2: Tall mature stems may bend under wind and heavy flower weight. Staking is recommended for gardens exposed to frequent strong winds. Q3: Can Cleome spinosa self‑sow in the garden? A3: Yes. If old seed pods are left on plants, it will readily drop seeds and produce new seedlings in the following growing season. Deadhead spent blooms to control self‑sowing. Q4: Can spider flower survive cold frost? A4: It is frost‑sensitive annual. Plant outdoors only after all frost danger passes; cold frost will quickly destroy foliage. Q5: What wildlife will these flowers attract? A5: Abundant nectar supplies draw large numbers of bees, butterflies and other beneficial garden pollinators.
