Question:

I have been given a small olive tree. The fruit is small and green and it has had some from the time I was given it. I put it outside when we had a shower on a warm day. Now it is back indoors my house faces west, so it will get the morning sun, in the room where it is at present. Should I keep it indoors? Should I keep it watered? The leaves and fruit are dropping. This was a gift to remind me of that lovely place, please help me keep it. (Mrs M J Nicholson, King's Lynn)

Answer:

The olive tree, Olea europaea, is instantly recognisable as the quintessential Mediterranean tree and stands as the archetypal sentinel of warm, sunny climes. It is then perhaps surprising that the olive tree is suitable for growing in a wide range of climates.

In the UK, olive trees perform well in the milder microclimates which, generally, are southern and western regions, coastal areas and urban locations.

Site in the sunniest position possible, ideally south or west facing with some protection from the north and east winds.

Plant in free-draining soil that will not become waterlogged during the wetter parts of the year; olives are tolerant of both acidic and alkaline soils. Poor sandy soils will benefit from of organic compost, and clay soils may require additional drainage.

Olive trees can successfully grow in containers for many years and we recommend mixing good quality multipurpose compost 50/50 with John Innes No.3. Never overpot your olive tree; always re-pot just to a slightly larger pot.

Olive trees can be easily pruned to maintain the size and habit required. I recommend that light, formative pruning is undertaken in mid-spring with heavier trimming in early to mid-summer.

Never prune during the winter, and be cautious in the autumn: like many Mediterranean trees, olives need some heat and recovery time to heal wounds before the dormant winter period.

Feed your olive tree with seaweed extract fortnightly between May and September to ensure the tree stays healthy.

In areas where the minimum winter temperatures are between -2�C and -5�C, olive trees require no winter protection and will even tolerate drops down to -7�C for short periods, providing the daytime temperature rises sufficiently. In areas of lower winter temperatures, your olive tree can be protected with several layers of horticultural fleece wrapped around the trunk and crown of the tree.

Like many plants grown in pots, olive trees have not yet evolved to tolerate frozen roots. But fear not! This can be prevented by adding several layers of bubble plastic to the inside of the pot when re-potting the plant or simply add layers of bubble plastic to the outside of the pot and secure with twine.

You are best to keep it in a cool room such as the bathroom or conservatory over winter and then put it out from April to November. The leaves will re-grow in spring as long as you stop watering it now.

For more information on exotic plants try Urban Jungle Nurseries, Norwich, 01603 744997.

•This article was first published on November 12, 2011.