Meet ‘Big Red,’ the Mystery Tomato : Gardening: Grown from seed of unknown origin, these tomatoes are as big as a baby’s head and taste great. The tall plants require sturdy support.

They’re as big as a baby’s head, these tomatoes that came from seed passed over the fence. John Wasulko of La Palma got them from a friend in Anaheim, who got his from a friend in Pennsylvania, who got them from who knows where. John says he thought the name was Russian Beefsteak, and they certainly are a beefsteak-type, and one of the biggest I’ve seen--a real county fair winner.

One slice smothers a hamburger bun, hanging well over the edges. They are so heavy, and the stems so thick that Wasulko needs a sharp knife to cut them from the vine. And the vines are nothing to kick sand at--they’re trained to 7-foot steel poles.

Says Wasulko, “If I didn’t cut off the tops, they’d be over your head, way over your head. They were headed over the wall (he points to a solid looking concrete block wall) when I cut them back.”

He doesn’t cut off the side branches however, but simply gathers them up against the body of the plant and ties a loop of twine around the whole thing.

The trellis he grows them on is a sturdy and clever affair made from threaded steel rod. “I have the trellis tied into everything--the block wall, the house, the patio supports. These tomatoes need a lot of support.”

“I once grew an 11 1/2-pound cabbage, but these tomatoes are more fun. My doctor loves tomatoes, so I brought him a bag and he couldn’t believe it. He says ‘I gotta weigh these’ and put them on the baby scale, and they came in at around 3 1/2 pounds apiece.”

Now is the time to plant tomatoes, even near the coast, because warm weather will be here for keeps by the time they start to fruit. Weather that is too cool prevents fruiting (and so does late-summer weather that it too hot).

If you want to try growing truly huge tomatoes like Wasulko’s, there is one promising source--a seed company devoted to tomatoes only--The Tomato Seed Co. Inc., P.O. Box 323, Metuchen, N.J., 08840.

They list their tomato varieties by size and shape and Group 1 is categorized as “huge, over 1 pound.” There are 23 kinds in this group, including old standbys such as Burpee Big Boy and Burgess Colossal Red, but also some unusual and unheard of varieties.

One named Bragger sounds real big, with fruit to 2 pounds; Oxheart is said to get to 2 pounds plus; Mortgage Lifter might just be the ticket for some of us, or how about Jung’s Giant Climbing or Watermelon Beefsteak, a pink variety?

Best yet might be Champs of New Jersey, which are actually seeds collected from each year’s winners at the Championship Tomato Weigh In, held in New Jersey, which is close enough to Pennsylvania to maybe include something like Wasulko’s giants.

(The standard big varieties named Beefmaster, Beefsteak Red, Giant Beefsteak and Ponderosa, by the way, are only considered “extra large” by this company, and are in their Group 2.)

Or, you might ask around, like John Wasulko did, and see if a friend or neighbor isn’t growing something extra big.

For any of these a big, strong support is required. The easiest to make is a cage of welded wire, the kind with 6-inch by 6-inch openings used to reinforce concrete driveways. You can find it at most building supply stores, and those 6-inch openings are important if you want to be able to reach inside and get these huge tomatoes out.

Buy the kind that is 8 feet wide and roll a 5-foot length into a cylinder to make a cage about 1 1/2 feet in diameter, enough for one plant. Use two sturdy 2-by-2-inch stakes pounded into the ground on either side to support the cage. Most large tomatoes are “indeterminate” types, which means they don’t stop growing, so you may have to cut out the top to keep them from going over the walls of their cage.

You can also expect any tomato named Oxheart, Mammoth Wonder or Russian Beefsteak to have big appetites, and Wasulko fertilizes weekly with a liquid fertilizer (appropriately, he uses one named Miracle-Gro). Wasulko started his plants from seed sown in pots and planted them in the ground on May 1, when they were about 5 inches tall.

For those who wonder if bigger is perhaps not better, these tomatoes have few seeds and are nearly solid inside. And, they taste great.