There will be some disagreement I'm sure - just as there is in the "to prune or not to prune" debates that have gone on forever - but I am convinced that size of fruit is primarily determined by the varietal genetics. Assuming proper soil prep, water, and fertilization, plant genetics determine fruit size so if large fruit is the goal then large-fruited varieties should be used and vice-versa. I guess it's the old "you can't make a silk purse out of a cow's ear" philosophy. ;)

While studies have shown that pruning can reduce overall production, I have never read or seen any definitive proof that pruning alone actually results in larger fruit. Most studies published on the question include all sorts of "qualifiers" and recommendations for modifying feeding and watering programs and removing blossom clusters to focus energy. But who's to say? It' worth trying I guess. ;)

All that said, Heartland is a dwarf indeterminate so it shouldn't need much pruning I would think. Removing new suckers shouldn't pose any problems but when the suckers get as large as you describe (suckers larger than the original stalk) I'd be really hesitant to remove them for fear of creating a good size wound for disease/insect entry. Heartland usually only gets about 3 feet as I recall and is bred for smallish 6 oz. fruit so I'm not sure you'll get any improvement in fruit size from pruning it. If size rather than number of fruit is your goal then try removing blossom clusters instead.

The others are indeterminates so they can be pruned if you wish but Jubilee again is only a medium fruit size normally.

Let us know how it works out for you.

Dave

Hello Shelley. Digdirt is steering you right. You'll notice that a sucker will grow like a new productive branch if left on the main stem. It'll have flowers and fruit just like the main. Most folks prune to get larger fruit but that's not a guarantee. The best way to get bigger tomatoes is to plant bigger tomato breeds. Oh, another thing, if you DO cut that oversized sucker off, just stick it in the ground and water it. The darned things grow. Best of luck.