Pruning Cherry Tomatoes: Suckers, Two-Stem Training and Topping

Two stems suits a cherry tomato better than one

With a slicing tomato you grow a single stem so the fruit sizes up. A cherry tomato is not trying to make big fruit, so that reasoning does not apply, and the extra vigor has to go somewhere. Run two stems and you roughly double the number of trusses without any loss of fruit quality, because a cherry fruit reaches its full size on almost any amount of leaf.

The second stem comes from the sucker immediately below the first flower truss, which is always the strongest one on the plant. Let that one run and remove every other sucker on both stems. Three or more stems is where it stops paying: the canopy closes over, the inside stays damp, and you lose more to splitting and mold than you gain in trusses.

Suckers come three times faster than you expect

A cherry tomato in warm weather produces a usable sucker at every leaf joint, and it does it continuously. Miss one week and you find shoots four inches (10 cm) long at six different joints. Miss two and the plant has become a bush, the inside is dark, and taking it back to shape at that point removes so much leaf at once that the plant checks and drops flowers.

The answer is a fixed day. Pick one day a week and do the whole round, working from the base upwards on each stem in turn. A sucker under two inches (five cm) bends off cleanly between finger and thumb, leaves a wound the size of a match head, and dries shut by lunchtime. That is the entire technique.

1. Go up one stem, then the other Start at ground level on the main stem, work to the tip, then do the second stem the same way. Jumping between them is how you miss joints.
2. Bend sideways until it snaps Grip the sucker at its base and push it sideways rather than pulling down. Pulling tears a strip of bark off the main stem and leaves a wound that takes a week to close.
3. Leave any sucker carrying open flowers If you find one already flowering, pinch out its tip one leaf above the truss. You get the fruit, and the shoot stops extending.
4. Take the prunings off the bed Removed suckers left on the soil are a mold nursery. Bag them, or stand a few in water on a windowsill and they root in a week as spare plants.

In a warm spell a cherry tomato can put on 14 inches (35 cm) of stem in a week. If you are going away for a fortnight, do the suckers hard the day before you leave, taking everything under six inches.

Tie in for weight, not just for height

Cherry trusses are long and they carry a lot of fruit. A single truss holding thirty ripening fruit weighs enough to bend the stem sharply and, on a hot afternoon when the tissue is soft, to kink it permanently. That kink chokes off everything above it. So ties on a cherry tomato are load-bearing, not just a way of keeping the plant upright.

Put a tie two inches (five cm) below every truss as it flowers, before the weight arrives. Wrap the twine tight around the stake and loose around the stem in a figure of eight, loose enough to slip a finger through. Cherry stems thicken noticeably between one week and the next, and a tie that grips today will be strangling the stem within a month.

1. Tie below the truss while it is still flowering Once the fruit has set the truss is already pulling on the stem. Two inches (five cm) below the truss node is the right spot.
2. Support long trusses from underneath A truss over eight inches (20 cm) long can be looped loosely to the stake with a second piece of twine so the weight hangs from the stake rather than the stem.
3. Retie anything that looks tight On your weekly round, run a finger under each tie. If it does not slide, cut it and replace it. The scar stays but the plant recovers.

Stake height decides where you stop

An unchecked cherry tomato will pass twelve feet (3.6 m) and keep going until frost. You are never going to ripen all of that, so the stake decides the plant, not the other way round. A seven foot (210 cm) stake driven 18 inches (45 cm) into the ground leaves you about five and a half feet (170 cm) of usable height, which is eight or nine trusses on a single stem.

There is another option with cherry tomatoes that does not work well with large-fruited types: lower the plant. Once it reaches the top of a stake, untie it, lay a length of the bare lower stem along the ground on a bed of straw, and retie the growing tip back at the bottom of the stake. The buried section roots, and the plant carries on climbing for another two months.

Topping and the last useful truss

About six weeks before your first expected frost, pinch out the growing tip on every stem two leaves above the highest truss you actually expect to ripen. Everything the plant makes after that goes into the fruit already set instead of into new growth that will never color. On a cherry tomato this is worth more than it sounds, because the plant is still trying to make new trusses right up to the frost.

Leave two leaves above the final truss rather than cutting flush. Those leaves shade the fruit from scorch and, more importantly, they are what feeds it. Cut immediately above a truss and the top fruit stays pale and hard. And keep doing the weekly sucker round after topping, because the joint just below the cut will throw a replacement leader within days.

1. Count back six weeks from first frost Cherry fruit takes about 40 days from open flower to ripe. Any truss flowering later than that will not finish.
2. Cut two leaves above the last truss Pinch the tip out with your fingers on a dry morning. The wound closes within a day.
3. Remove trusses that are still only flowers Any truss at flower stage in the last six weeks is a drain. Pinch it off whole and the set fruit fills faster.

Recovering a plant that got away from you

Most people lose control of a cherry tomato at some point in midsummer, and the plant is almost always recoverable. The rule is that you take it back in stages. Removing half the canopy in one session causes flower drop and sunscald on fruit that has been shaded all summer, so spread the work over two or three weeks.

1. A sucker has become a third stem If it carries trusses, top it one leaf above the highest one and remove it entirely after you have picked. If it has no fruit, cut it out at the base now.
2. The whole plant is a thicket Take out no more than a third of the excess growth per week. Start with shoots growing into the middle, then the ones pointing at neighboring plants.
3. The tip snapped under fruit weight Let the highest sucker below the break run on as the new leader and tie it in. Cherry tomatoes replace a leader within about ten days.
4. Fruit is scorching after pruning You took too much leaf at once. Stop pruning, and drape shade netting over the row for the next fortnight until new leaf covers the fruit.