Q&A - Trees

Q. I have a holly bush in my garden that appears to be very healthy but has never had any berries. I know that for a holly bush to have berries you need to have a male and a female bush in close proximity. How can I tell whether I've got a male or female holly bush so that I can plant one of the opposite sex and get the berries?

A. There is not an easy way of telling the sex of a holly (Ilex). The easiest way is to buy one of each sex or check your neighbourhood to see if there are berrying holies nearby, if so then yours is likely to be a male.

Q. I want to see if I can get some acorns to grow, what would you advise is the best way to get them started.

A. It is quite easy to grow Oak trees from acorns. Once you have collected them in the autumn you should sow them either in pots or in a prepared piece of ground into which well-rotted manure or compost has been dug. Plant them about 1cm deep (1/2") and cover them with mesh to keep the mice and squirrels from stealing them. Water and wait until they shoot in the spring. You should then pot them on the following autumn or space them out and then plant them out into their final position over the next year or two.

Q. I have been given an olive tree as a present and don't know where to keep it and how much water it requires. I have a conservatory, greenhouse, and sunny garden.

A. Your olive is a native of the Mediterranean and therefore needs plenty of warmth and light. The conservatory will be ideal. Give it a reasonable amount of water in the summer allowing any excess to drain out the bottom of the pot and keep it slightly on the dry side during the winter. Make sure the planting mix contains plenty of well-rotted manure or compost, is well drained and feed with a general fertiliser every spring.

Q. I have recently bought a Phoenix canariensis. Could you please tell me what kind of soil they prefer, when /if to repot and are they strictly indoor plants.

A. Phoenix canariensis is really an indoor plant in this country although you could put it out on the patio in summer. It grows in any good compost in a pot and must be well drained. Water sparingly particularly in winter. It likes lots of light but is tolerant of a bit of shade. Red spider mite can be a problem so look out for mottling of the leaves and spray with a houseplant insecticide immediately.