Kim Wilde answers your gardening questions.
I use henna to colour my hair. Is it possible to grow a henna tree (Lawsonia inermis) in central Scotland?
This beautifully fragrant plant is a shrubby tree that produces henna from its leaves. The plant comes from the semi-arid regions of northern Africa and south-west Asia, so the cold and soggy Scottish climate will not do. Room temperature is fine - a heated greenhouse or conservatory with a minimum temperature of 70F is ideal. During summer they will enjoy being outside, where you can give them a thorough drenching occasionally; but make sure they are not in a draught. They prefer direct sunlight, and the plant's soil should be allowed to dry out between watering, which can be done every four to six days. Henna plants benefit from feeding monthly, and will keep bushy if you pinch out developing shoots.
I have a Prunus x subhirtella 'Autumnalis' . Each spring, spots appear on the leaves which then become holes. Please help.
The holes on your leaf specimen have more of a 'shot hole' look than a ragged hole, so it's likely to be bacterial canker. Spray whole tree thoroughly with a copper-based fungicide, mid-August to mid-September, and again in mid-October. Beforehand, spray with Bordeaux Mixture in spring to help control leaf spotting.
I recently bought a bougainvillea, which has lived quite happily in a pot outside the front door until the first frosty nights scorched some of the leaves. How do I look after it over the winter?
Bougainvillea requires a minimum temperature of 10C. Place your pot in a bright area which remains warm during the winter nights; this should help prevent it from going into dormancy, keeping it in better shape for spring. Don't be surprised if it does go into dormancy and all the leaves fall off. Just keep the soil slightly damp and start feeding next spring with a high nitrogen liquid feed, changing to a high-potash feed as flowering starts. Light pruning after flowering will keep it in shape. Don't be in any rush to re-pot, as bougainvillea flowers better when pot-bound.