Fill a sunny border or patio pot with the semi-double golden-yellow flowers of Coreopsis Double the Sun, a compact perennial grown from primed seed.
Ready to grow a golden display? Follow our step-by-step Coreopsis Grow Guide for primed-seed sowing, transplanting, regional timing and flowering care.
Quick Grow Facts
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Plant: Coreopsis grandiflora ‘Double the Sun’; compact, clump-forming perennial.
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Seed form: 10 or 500 primed seeds. Primed does not establish untreated status; check the packet’s treatment and storage instructions.
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Position: Full sun; free-draining soil or container mix.
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Mature size: About 30–36 cm tall and wide; golden semi-double blooms about 6 cm across.
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Breeder sowing reference: For primed Double the Sun, PanAmerican specifies trays, a light covering of vermiculite and 18–20°C; germination light is optional. Current retail-packet directions still need confirmation. Do not add soaking or chilling unless the supplier directs it.
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Germination: The breeder’s 3–5 days is from 50% to maximum germination, not from sowing. A sow-to-emergence range for the current retail lot is not confirmed.
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Moving on: Transplant sturdy, rooted seedlings after gradual hardening; protect young plants from frost. Small-plug production commonly takes 5–7 weeks.
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Garden spacing: 36–41 cm; this is a compact bedding variety, with no verified intensive cut-row recommendation.
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Season: Choose a mild local starting window. Use the guide’s separate advice for winter-rainfall, frosty, humid and hot interior gardens.
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Flowers: First-year flowering; allow roughly 14–17 weeks under favourable production conditions, potentially longer outdoors. Longer days encourage flowering.
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Care: Water establishing roots, drain freely, feed moderately and deadhead. Routine pinching or staking is usually unnecessary; give exposed plants support if needed.
Before sowing: the online packet artwork still lists 1 cm depth and 15–20 days, which has not been reconciled with the breeder’s primed-seed guidance. Please ask GARDENING.co.za to confirm the instructions for your lot before sowing. No expiry date or germination guarantee is implied.
If growth struggles: check sowing depth, temperature, moisture and storage history. Keep seedlings airy and protect newly planted roots from heat, wind and frost. The guide explains failed emergence and establishment in more detail.
Seed safety: for ornamental growing, not food, sprouts or animal feed. No edible or pet-safe claim is made. Keep seed away from children and animals; follow all packet warnings.
Supplied by Ubuntuberg Seeds.
