Farmers have been using computers for years for such things as measuring milk production from their cows, drawing up profit and loss statements, keeping track of livestock breeding cycles and maintaining inventories - often e-mailing feed and seed orders to their local co-op. Some farmers have become adept at buying and selling their implements, tools and other gear on eBay, a popular online auction site.

Now it's the home gardener's turn. Gardeners are using computers for everything from operating lawn-sized irrigation systems to determining how much insecticide should be dusted on tomato plants, from running digital weather stations to logging the return of the first migrating hummingbird.

Some people use their computers to track the average dates of killing frosts. Many others buy special software to help landscape their property, plot the shape of their vegetable plots and flowerbeds or suggest how to rotate their plants from year to year.

Computers also can be used for some heavy-duty winnowing when stocking up supplies for the next planting season, said Kathy Purdy, a gardener and freelance writer who lives near Chenango Forks, N.Y.

''You use a spreadsheet to list every plant or seed you want from a certain catalog and it keeps a running total as you go,'' Purdy said in an e-mail interview. ''You can figure out exactly what has to be dropped from the order to stay under budget. This is a great way to pass the winter months.''

With camera-capable cell phones, wireless laptops, personal digital assistants (PDAs) and Web browsers, the plant doctor is always in.

If you spot what appears to be a disease or insect problem while strolling through the garden or orchard, you can take a digital photograph, jot down some notes and then query one of many university extension service computer databases for identification, background and a suggested remedy.

''Technology is faster, better, cheaper,'' said Bob Boufford, an e-learning specialist with the University of Alberta and author of The Gardener's Computer Companion. ''You can see a problem and solve it within minutes.''

Many golf courses, lawn and garden stores use computers to help with the care and feeding of turf and plants, Boufford said. ''That kind of gear is filtering down to the home environment. It's often not as sophisticated as what you might see on golf courses but there are some pretty fine residential set ups.''

Computers aren't yet capable of pulling weeds but like tough-love schoolmasters, they can keep an eye on all your growing things. ''Some people post Webcam pictures on the Internet so they and others can watch what's going on in the garden all the time,'' Boufford said.

Probably the most valuable service computers provide, though, is swinging open the gate to a great storehouse of information.

''It's phenomenal,'' Boufford said. ''That's where we see the biggest benefit. It's the access to the resources and the experiences of a wide garden community.''

Understand, please, that the garden community about which he speaks is not just neighborhood wide. It's worldwide.

Marion Owen, a gardener and garden writer from Kodiak, Alaska, gives an all-new meaning to ''over-the-fence'' chats with other growers.

''I compare notes about currants and runner beans with a friend in Scotland and I chat about potatoes with a gardener in Finland,'' Owen said. ''Though we haven't met in person, I cherish them as friends, nonetheless.''

There are larger cyber-communities from which to gather information - online forums, for example, that also offer opportunities for socialization. And then there is the increasing popularity of garden blogs, personal Web logs that read like journals and generally deal with a single theme.

''The big thing about garden blogs is that they have become a loosely organized garden club on an international scale,'' said Purdy, a self-described ''information packrat'' who reads so many garden blogs each day that she designed a ''feed reader,'' which collects content from different sources and then provides an index to keep track of them.

Other resources:

* The Gardener's Computer Companion, by Bob Boufford (No Starch Press, $39.95)

* http://webgarden.osu.edu: More about computer-assisted horticulture at this Ohio State University Web site.

* http://www.coldclimate gardening.com/garden-blog- directory: Kathy Purdy's directory, where you can determine if there are any garden blogs you would like to bookmark.