All tomatoes are either Bushes (determinate) or Vines (indeterminate).
Determinate tomatoes stop growing on their own, and produce all of their
fruit at once. Your heirloom tomatoes are vines, or "indeterminate."
This means they will produce fruit all season. If left alone, they will
grow into an unruly
tangle of stems.
If you're short
on space and if you want earlier and larger
fruit, then prune!
Mother Stem: The main vine. Everything else will come off it. It
wants to split into many branches, but you won't let it.
Leaf Stems: Growing off at right angles, these little fellows break
the vine up into sections. They get leaves and help with photosynthesis.
Flower cluster: These grow in the middle of sections, coming directly
off the vine. These flowers become fruit—we love them!
Suckers: These grow out of the crotches of the right angle leaf
stems. They must be removed—pinch them off with your fingers.
For a well-behaved vine, prune to a single stem, or a y-shaped vine with
a short mother stem and two long main stems. In areas with intense
sun, such as the southwest, more leaves are welcome—a single
stem can result in sun-scalded fruit. Make sure to pinch off dead leaves.
• Pruning is easy—snap out the suckers that grow out of the
crotch made by the leaf stem joining the main stem. The best snapping-time
is when suckers are 3 to 4 inches long.
• For a double stem, or Y-shaped vine, allow a sucker near the lowest
flower cluster to grow.