When can these plants be planted ?
Some species will tolerate only light frosts, but some of the perennials are more frost-hardy. They will grow well when planted in full sun in well drained light soil with adequate watering in the summer.
You can propagate from seeds in the spring, cuttings in early summer, or division at any time.
Pests, diseases or disorders
Watch out for snails, slugs and caterpillars.