division or separation
- Can be grown from seed, but varieties must be propagated vegetatively, except for 'Variegata', which breeds true from seed.
Plants freely self sow. But if planting the seeds, start them in pots in a cold frame, and grow until well-established before planting out.
Take stem cuttings of half-ripe wood in July or August and hold in a cold frame until well rooted.
Take root cuttings of young plants in spring.
Layering in early summer is easy. Old plants will often self-layer.
Caution: Rue is poisonous and can cause skin irritation. Wear gloves and long sleeves.
Prune stems back to 6 to 8 inches in early spring to shape plant and encourage new growth.
Deadhead or remove flowers when they are just developing to prevent foliage from yellowing and fading. Do not prune in late summer or plants may not harden off in time for winter.
Seldom needs division. May need mulching for winter protection.
More growing information: How to Grow Perennials