Delphiniums and lupins

Q I love delphiniums and lupins, but seem to have trouble keeping them going. They last for a few years, but then just disappear. I don’t want to give up, so what should I do? Any advice you can give would be most welcome. Maggie Douglas, Shap, Cumbria

- Anne Swithinbank

A Unlike some other herbaceous perennials, delphiniums and lupins are relatively short lived, especially on heavy soils in wetter parts of the country. They thrive as youngsters, reaching a magnificent peak after three or four years, but the crowns turn woody as they age and can rot after a cold, wet winter. They are usually good for seven years.

Good care from the outset will give these showy plants the best chance of doing well, so plant young delphiniums into really good soil. They love full sun, with shelter from winds that might rock their tall spikes. To make sure our plants thrive, I often plant them into the kitchen garden where the soil is rich and well cultivated. Lupins prefer a slightly acidic and moderately fertile soil, but can also grow in alkaline and neutral conditions. Both require well-drained soil, so if yours holds water in winter, a slightly mounded or raised bed might help.