Quick Questions & Answers

QWhat is this tree, and how should I prune it? Caroline McGuigan, Malmesbury, Wiltshire

AIt is Pittosporum tenuifolium, which is best pruned now, but only lightly. Cut back overhanging stems to side shoots.

If you have to shorten limbs to where there are no side growths, smear Vaseline over the cuts to keep tissues moist and keep alive the invisible latent buds around the wound, which will take about six weeks to burst into growth.

QIf I cut a couple of foxglove flower spikes for indoors, will it ruin the plant? Craig Stewart (via email)

AIf it is the common, biennial Digitalis purpurea it won’t matter if you cut it.

If it is a perennial species such as ferruginea, which has small, brownish florets, cutting flower spikes will strengthen the plant because it won’t put all its energy into producing flowers and seeds.

QIf I pull up and dry off my old wallflowers, will the seeds be mature enough to save and use next year? Suzanne Shaw (via email)

AUnless the seeds are completely mature – in which case the seed pods will crackle and seeds rattle loosely inside them – your wallflower seeds may have insufficient vitality to germinate next year.

Yours still look green, so you should wait a little longer until they are fully ripe before removing the plants and saving the seeds.