by Callie

Grow Mammoth Tomatoes

To the tomato lover who gardens, a ‘large’ tomato is one that you only need one slice to cover a piece of bread. To grow tomatoes that will cover an entire plate? Only, if you plant Big Zac tomatoes. Look at that thing! You could feed a village with a single fruit.

No, it’s not photoshopped. Big Zac is super huge. The largest one grown to date was over 8 pounds. The one in that image above just tipped past 4 pounds on the scale, and the gardener was wise to pick it when he did because there are pics of fruits much larger floating around. I hope those people just grew them out to see how big they would actually get because they’re imperfect at 4 pounds, and downright scary looking after that…. all catfaced, and contorted. You’d waste a lot of meat cleaning them up and likely discover bad spots because of it. Best to pick them when they turn red, instead of trying to beat the world’s record.

When I first saw that image up there I thought it probably wouldn’t make it to ripe fruit stage in a shorter growing season. Surprise! It’s an 80-day tomato, so yes, it’s feasible to grow Big Zac as far north as Zone 4. Mind you, you would have to start your plants extra early under strong lights because if frost is early and summer temps are lower than they should be, you might not be able to vine-ripen the tomatoes. Of course, you can always buy a few extra weeks with a makeshift greenhouse to protect it from freezing before it finishes. Sound kinda crazy – like too much work? You’re not a Northern Tomato Lover. The things we will do to grow them can border on the extreme, but it works out in your favor quite often.

19 Inch Girth! Big Zac Tomato

Courtesy of Mario Bross

They say it’s delicious, meaty, and the perfect balance between sweet and acid. Definitely got to grow this one next year. In fact, maybe I can still get a plant from somewhere. Naturally, it will cost a small fortune, but that’s all part of the tomato growing adventure. A lot of fun is rarely super cheap šŸ˜‰

Don’t get the idea that this is some frankenfood gene splicing concoction. Big Zac is the result of manually crossing two super huge heirloom beefsteak varieties, the handiwork of oneĀ Minnie Zaccaria inĀ New Jersey. She’s an old hat tomato grower who has won the largest tomato competition 7 times in the past 20 years. How did she do it? By crossing the largest heirloom beefsteaks she could find, a project that bore fruits bigger than any other tomato plant out there. They’re so big you have to engineer support to keep the on the plant… or pick them early.

Giant Tomato Trussing: Big Zac Needs Support

Trussing Big Zac – Courtesy of Delectation of Tomatoes

Some thoughts on having better luck at bringing a Big Zac to harvest in better shape.

  1. Too much moisture causes tomato skins to split open, a trait that many large fruiting heirloom tomatoes share. Don’t over water them. Before you activate the spray nozzle or let the sprinklers rip – check the soil moisture with your finger. If it’s still wet an inch below the surface – wait a day – at least after they’ve rooted well into the ground soil. Young plants whose roots are mostly still in the cell-pak root ball will need watering every day unless you get lots of rain.
  2. Catfacing, which describes misshapen fruits with scars and irregular bulges at the blossom-end… shown below. It’s caused by tomatoes being exposed to temps below 50 degrees, so while frost may not threaten, on chilly nights you really should cover tomatoes. The damage is done to the flowers and carries out in the fruit later on. It can affect blooms as much as three weeks into the future too. The good news is that its usually only the first fruits thatĀ are affected, but cold snapsĀ happen at both ends of the season, so be prepared to engineer a shelter to cover that well-developed tomato plant as fall comes on. It will let you vine ripen your crop a couple of weeks longer that open to the elements does.


Any kind of cracking on your tomatoes is caused by too much water.

Cracking – Courtesy of UCANR Blog


Exposure to cold weather damages tomato flowers, causing catfacing, but they're still edible.

Catfacing – Courtesy of Mercury News


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Only strangers knock on the door at Callie's house. People who know her don't bother if the sun is shining - they know to look in the garden.