Sandy Paul is growing 14 varieties of tomatoes, 75 plants in all, in the basement of her 19th-century Burlington County farmhouse. "My jungle garden," she calls it.

Actually, until very recently when she gave some away, Paul had 100 tomato seedlings down there, along with dozens of peppers and eggplants. But make no mistake: In Paul's house, as in most American gardens, tomatoes rule.

Her favorite — one of them, anyway — is Cherokee Purple, a dense American Indian heirloom with smooth skin, rosy flesh, and funky green "shoulders." The taste is often described as rich, dark, and sweet, and if your mouth isn't watering as you read this, you need to get out more.

"I love it, it's just my absolute favorite, and you have to grow what you love," says Paul, a master gardener and retired finance executive from Chesterfield who, judging from the leafy riot in her basement, has an abundance of warm feelings for Solanum lycopersicum in all its variations.

So you can just imagine her excitement for the coming deadline, when freezing temperatures go from probable to possible to unlikely, meaning tomatoes can safely go in the ground. "May 15 is a sure winner," says Paul, displaying a self-control many gardeners lack, especially this year, when it was hard to tell winter from spring.

Still, Bill Kozma of Norwood, a computer operator and master gardener whose friends kid him about his devotion to tomatoes, thinks Paul is on the right track. While it's probably OK to plant tomatoes now, he says, "To be safe, wait till Mother's Day.

Which, if you aren't one of those impulsive types, gives you about two weeks to decide what to plant. And on that subject, Steve Bogash has plenty of suggestions — with data to back them up.

Since 2000, Bogash, an educator with the Penn State Cooperative Extension in Franklin County, has been running annual tomato trials and taste tests involving hundreds of tomato-loving consumers and new, as well as tried-and-true, tomato varieties, more than 300 in all. His master gardeners grow about 70 kinds a year, offering up about 30 to be tested at any one time.

"Originally, the purpose was to get home growers to grow varieties that they wouldn't typically find at garden centers, to open up their horizons a little bit. A lot of gardeners still think a tomato has to be red and round," he says.

The test is about as blind as it can be without literally blindfolding the volunteer tasters. For five hours, they work their way around the tables, sampling good-sized chunks of slicers and whole grape or cherry varieties, all unlabeled. They write down their impressions of flavor and appearance on a scale of 1 to 5. The ballots are tallied, the tomatoes ranked and finally identified, and the feedback made available to seed companies, commercial growers, and home gardeners.

To complete the record, Bogash and the master gardeners add their own observations on taste and aesthetics, as well as production rate, ripening qualities, sugar levels, firmness, disease resistance, and ease of training. (And while Bogash insists that sampling 30-odd tomatoes in a single lycopene-saturated rush is a tough slog for the taste buds, we consider this a sacrifice worth making.)

So ... which are the current champions, at least until the next round of tastings on Aug. 22?

Top red slicer of the last few years is BrandyBoy, a Burpee introduction that combines the legendary flavor of the Brandywine heirloom with the hybrid's high yield and disease resistance. "When gardeners ask what single tomato to grow, this is the one. It's a real winner for me," says Bogash, who is not on the payroll of Warminster-based Burpee.

Two other Burpee hybrids were singled out in the 2011 trials — Bush Early Girl and BushSteak, both small enough to grow in containers.

In the ever more popular heirloom category, testers' choices included Pineapple, a yellow beefsteak that Bogash uses in tomato juice; Mortgage Lifter and Arkansas Traveler, which unusually have both excellent flavor and high yields; Marianna's Peace, which has huge pink fruits; and Stupice, an early producer from the former Czechoslovakia.

For cherry and grape tomatoes, Sun Gold has been a consistent winner, but Sakura Honey, a 2011 introduction from Johnny's Selected Seeds, is the one to watch. "This variety really stood out from the pack with amazing flavor and beautiful pink grape-shaped fruit," Bogash says.

In the patio/container category, besides Burpee's two, testers liked Sweet 'n' Neat (red, scarlet, and yellow), which produced "copious amounts of delicious fruit on very compact plants."

There are lots more on the honor roll, many of them personal favorites of Ray Eckhart, a master gardener who works with Bogash on the trials and grows 20 kinds of tomatoes, 60 to 100 plants, in his home garden: "I like varieties that look funny, that aren't typical round, red things, weird shapes and stripes, that, in addition to flavor, might look like an oxheart or be bicolor.

"I think that's fun," says Eckhart, who cans, freezes, dries, and gives away his tomatoes, and only recently polished off the last of his 2011 tomato juice.

There is a science to all this inspiration.

Chelsey Fields, vegetable production manager at Burpee's Fordhook Farm in Doylestown, says it's very important at the trials she runs, as well as in home gardens, to give tomatoes their space. "Crowding leads to disease. The nice humid environment in there allows every bug and fungus to make a bed," she says.

She suggests planting tomatoes much deeper than soil level — a 12-inch plant can go down eight inches, which creates a hardy root system, which in turn maximizes fruit flavor. She also likes drip irrigation systems, on timers, for consistent watering; compost, straw mulch, or salt hay to enrich the soil; and crop rotation to cut down on soilborne disease.

We end with a surprise. Despite the fact that she gets paid to, among other things, grow, test, and taste tomatoes, Fields has a confession that's bound to make tomato-lovers crazy: She is not obsessed with tomatoes. "Actually, my husband and I are huge pepperheads," she says.