When to plant
In cooler climates, plant Watsonia corms in spring after the risk of frost has passed. In milder zones, planting in late summer or autumn is possible to give early establishment.
Where to plant
Choose a site with full sun or light shade. Watsonia performs best in bright positions. The soil must be well-draining, as corms are vulnerable to rot in waterlogged conditions.
Preparing the soil
Loosen soil to a depth of about 20–25 cm, removing stones and debris. Mix in compost or organic matter to enrich the soil. In heavy soil, add grit or coarse sand to improve drainage and prevent sogginess.
Planting the corms
Place corms pointed side up, burying them 10–15 cm deep (or 4–6 inches) and space them 12–25 cm apart depending on variety. In containers, use a deep pot with a free-draining mix.
After planting
Water thoroughly to settle soil around the corms. Maintain moderate moisture during growth, especially when shoots emerge, but avoid letting the ground become waterlogged.
During growth & blooming
Leaves emerge first, then tall flower spikes form. Feed with a balanced fertilizer during early growth and as buds form. Support tall spikes if needed. After flowering, remove spent flower stalks but leave foliage intact until it yellows.
After blooming / end of season
Allow foliage to die back naturally to replenish the corms. In zones with frost, lift the corms once foliage has withered, dry them, and store in a cool, dry place until next planting. In frost-free regions, corms may be left in place with a layer of mulch for protection.
Extra tips
Watsonia can multiply by producing small cormels and may become vigorous over time — divide crowded clumps during dormancy. In poorly draining or cooler areas, grow in containers you can move. Because some species propagate by “bulbils” (small cormlets along the stem), be cautious of unintended spread.
