People who want advice on gardening dilemmas, from designing and pruning to pest identification and plant combinations, may have always relied on the staff at the local garden centre, green-fingered neighbours, or Gardeners' Question Time on Radio 4.

But there is a wealth of information and opportunities to expand your horizons on the internet, if you know where to look.

You can swap seeds and plants and share information and experiences with other gardeners and allotment holders on a variety of websites, some of which are better than others.

For easy-to-understand information from the likes of Alan Titchmarsh, you can't go far wrong with popular garden website crocus.co.uk, which features advice sections from TV's best-loved gardener.

If you buy a plant from the company, you automatically qualify for its plant aftercare service, which now includes regular care tip e-mails from Titchmarsh himself.

If you want to encourage wildlife to your garden, check out the new database at the Plant Press, www.plantpress.com, an online version of Gardening With Wildlife In Mind, from English Nature, which shows the relationship between garden plants and creatures that depend on them and focuses on 300 or so distinctive and desirable species.

On the same site you'll find the free online Plant Encyclopaedia now with more than 4,500 plants and more than 10,000 photographs.

If you want to grow seeds of vegetable varieties which are not widely available, it may be worth joining the Heritage Seed Library, run by leading charity Garden Organic.

Garden Organic has a collection of 800 old and unusual vegetable varieties, collected over the years, including several late 19th century tall peas, including Champion of England and Ne Plus Ultra.

The library aims to conserve and make available vegetable varieties that are not widely available. You can join the HSL for an annual fee of £20 (or £15 with Garden Organic membership).

Members receive their choice of up to six varieties and there is also also an informal seed swap section run between members themselves. For details go to www.gardenorganic.org.uk If swapping plants is more your bag, on February 28, www.plantsreunited.co.uk goes live, a new on-line gardeners' market which allows members to swap, buy or sell plants of their choice, for an annual membership of £12.

There will also be gardening advice, weather forecasts and a chance to discuss horticultural issues as well as seek advice and put forward your own tips.

"All too often a much sought-after variety is not available from conventional gardening retail outlets," says gardening PR specialist Graham Paskett, who is launching the site.

"Logging on at plantsreunited puts gardeners in touch and gives them the opportunity to post wanted' varieties."

One site which is free to join and allows people to share their gardens online is www.growsonyou.com.

Members can exchange hints and tips across generations.

The homepage offers a number of options including browsing the open garden's section, asking a gardening question or writing a blog. As a member you can ask questions of other members and add a photograph to explain your question.

Some members use the site to document their gardening experiences outdoors. You can also use the Colour Inspiration tool where you can search for a particular shade of flower or plant, which then matches up to members' photographs posted on the site.

Co-founder Ajay Mathur says: "We are not experts on gardening but whatever pests, weather or geography you're dealing with, you can be sure one of the gardeners out there will have had similar experiences in one of their gardens."

Of course, there's a plethora of blogs from gardeners offering tips and advice based on their own experiences, but one of my favourite informative websites is www.digmyplot.co.uk, which offers some really good advice on growing fruit and veg organically.

So if it's raining or frosty in the run-up to spring, you can make the most of the advice which you can tap into, or start swapping seeds and plants, from the comfort of your home.