Ask Alys: your gardening questions answered

We have a large Jerusalem artichoke bed. They grow like trees and last year did a sunflower routine with yellow flowers. The artichokes seem to be getting smaller but I want to leave them where they are. Would it help the tubers to grow if we chopped the heads off the plants at this stage? Chop the flowers off if you wish, as a lot of energy is directed to flowering rather than swelling the roots. I cut back the tops around July, particularly of the front row. This means they don't overshadow other plants, and I find short plants survive autumn winds much better. I like the flowers, so I sacrifice the back row and let these flower. In early spring sift through the remaining tubers. Be ruthless and eat up or chuck out all the smaller tubers, keeping only the plumpest for next winter's crop: even fragments will reshoot into plants. Keep only tubers the size of an egg and replant them 45cm apart in each direction. (The smaller ones I make into chutney .) • Do you have a question for Alys? Email [email protected]