You'll often hear this being talked about by gardeners, especially at this time of year: but what is it, and why do we do it? There are various theories about…
Grow them in a cool moist fertile soil with partial shade, but they will tolerate full sun. They may need staking.
You will need to divide the plants every third year in the autumn or late winter.
Pests, diseases or disorders
What out for aphids and fungal stem rot.