Q What is the best way to divide lupins?
Elaine Sykes, by email
A
BOB SAYS Forget advice about digging up perennials and forcing clumps apart using two forks back to back. I’ve never seen this work easily, and certainly not with lupins, which have few, rather fleshy roots. Maybe it worked with more fibrous clumps in the days when beds were heavily manured and looser from frequent digging. It’s easier to dig up clumps and immerse in water to soften the soil. Once part-washed, you can see what you’re doing and can then detach offsets from the outside, with a knife if necessary.
However, this is not the best method for lupins. Instead, pot up the clump in autumn, a tad deep. Keep under cover, then take young growths with a few leaves from the crown in early spring. Pot up and grow on in a coldframe.