GARDEN GURU

I’ve been given conflicting

Q advice about how often to prune box topiary. A friend says plants need cutting only once a year, while my neighbour suggests they should be pruned more often. Who is right?

Naomi Williams

Your neighbour is bang on. It A used to be recommended that box topiary was given its first cut on Derby Day (the first Saturday in June) with a follow-up trim in early autumn. However, many professionals now recommend cutting whenever a sharp silhouette is lost under fresh growth.

Can you explain the

Q meaning of angustifolia, as in the botanical name for English lavender, Lavandula angustifolia. I know folia means leaf, but what does the other bit mean?

James Noble

The angusti part of the name A comes from the Latin word

angustus, meaning narrow. So, the two words together simply means ‘narrow leaf’.

Our 15-year-old azalea was Q admired by many when in bloom, but over recent years there have been fewer flowers. It has a crusty grey growth on the branches, so will

pruning help bring it back to its former glory? Jenny South

The grey stuff is lichen and A

won’t harm it. I think it simply needs moving into a bigger pot to give it more room to grow. Re-pot with John Innes ericaceous compost and get it off to a flyer by feeding with a fertiliser for acid-loving plants.