We've all heard about global warming and, although its causes are still disputed, most scientists and environmentalists now agree that our climate is definitely changing. As gardeners, we are more likely than most to notice these changes, but will we benefit from them or suffer the consequences?

The National Trust and the Royal Horticultural Society, together with DEFRA, Anglian Water, the Forestry Commission, Notcutt's Nurseries, the Royal Botanic Gardens Kew and the UK Climate Impacts Programme, have commissioned and recently published a report entitled Gardening in the Global Greenhouse: The Impacts of Climate Change on Gardens in the UK. It can be viewed in full, or in summary, by logging on to the RHS website at www.rhs.org.uk and it makes fascinating reading.

It seems that over the next few decades we can expect earlier springs and later autumns (in effect a longer growing season) with increased winter rainfall and fewer frosts, together with warmer, drier summers.

The effects will be more pronounced in the south and east of the country, but they will also affect us here in the North West.

They don't sound too bad do they? We will be able to grow more exotic species like apricots, citrus fruits and olives, our fruit and vegetables will have more time to ripen and mature, and we may be able to grow half-hardy perennials like marguerites and Felicia all the year round. Rising temperatures and extra CO2 can increase plant growth by up to 50 per cent, with improved germination, flowering and fruiting for many plants.

Not all the news is good though. Lawns will be drier and patchier in summer, but carry on growing all winter (year round mowing!) Weeds too will grow all year round; annual weeds will be able to complete more life-cycles and seed even more prolifically through our gardens. Greenhouse pests such as red spider and whitefly may be able to attack outdoor plants; already pests such as the rosemary beetle and the lily beetle are becoming a problem in the south of England.

Milder, wetter conditions will encourage fungal diseases, and we may have problems maintaining soil fertility as nutrients are washed away by winter rains. Plants that will suffer include those that prefer a cold winter (daffodils, bluebells, snowdrops and crocus) and those that need cooler conditions in summer (rhododendrons, ferns and alpine plants).

I am confident that we gardeners will be able to adapt to these changes, as long as we recognise they are happening and treat them as a challenge rather than a threat.

Incidentally, the RHS website has many other items of interest to gardeners, including information on RHS gardens and events, new and unusual plants, advice for gardeners, and publications. It's well worth a visit.

January 16, 2003 10:00