edenhana

Sweet William

Traditionally grown as a biennial - sow in spring for flowers the following early summer - though quick-flowering modern varieties will bloom in their first season from an early spring sowing.

Sun
full sun
Water
moderate
Spacing
20cm
Difficulty
beginner
Grows in
Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson, Tasman, Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago, Invercargill / Southland
Mature height
40cm
Flowering season
Jan, Nov, Dec
Common diseases
Rust
Common pests
Aphids

When to plant by region

In Whangārei / Northland, Auckland, Hamilton / Waikato, Tauranga / Bay of Plenty, Gisborne, Napier / Hawke's Bay, New Plymouth / Taranaki, Palmerston North / Manawatū-Whanganui, Wellington, Nelson and Tasman: September-November. In Blenheim / Marlborough, West Coast, Christchurch / Canterbury, Dunedin / Otago and Invercargill / Southland: September-October.

Growing stages

  1. Germination & planting

    • Sow in spring for flowers the following early summer, or choose a quick-flowering modern variety to bloom in the first season
    • Space seedlings around 20cm apart in a full-sun position

  2. Establishment (first-year rosette)

    • Traditional types spend their first year building a low rosette of leaves rather than flowering
    • Watch for aphids clustering on young growth
    • Free-draining soil matters more than heavy watering for this dianthus while it establishes

  3. Vegetative growthOver winter, ahead of second-year flowering

    • Rust is the main disease risk, so avoid wetting foliage when watering and clear away fallen leaves
    • Aphids can persist through the cooler months on new growth

  4. FloweringEarly summer, in the plant's second season (or first season for quick-flowering varieties)

    • Traditional biennial types flower in their second summer, so don't expect a display in year one
    • Keep watch for rust on foliage during humid summer weather
    • Deadhead spent blooms to tidy plants and prolong flowering

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