Watsonia are South African plants which grow from corms like crocosmia or gladioli. Sadly they are half hardy plants even in Cornwall and are therefore best grown in pots in the greenhouse or lifted and taken inside for the winter. Here they will produce sword shaped leaves and showy spikes of tubular red, orange, pink or white flowers at various times during the year.
In the conservatory at Burncoose we have had great success with W. ‘Tresco Hybrids’ and W. pillansii. These clump forming plants have self sown themselves in profusion and flower away in summer and autumn. We have been experimenting with other species of watsonia and hope to offer other varieties in the future of these attractive plants.
If you are brave enough to try these outside in frost free areas they like a moist well drained soil which will not dry out in summer. Mulching for winter protection is essential. In the greenhouse they grow in potting compost in full sun and water freely except when dormant in the winter.
Sow seeds in the autumn or divide clumps of corms in the spring before they come into first growth.