Which bits do I pinch out on a tomato plant?

This is the job people most often get wrong on their first tomato plant, usually by pinching out the trusses and leaving the side shoots. The three things growing off the stem look similar for about a week, and after that the difference is obvious — so the trick is knowing where to look rather than what it looks like.

Step by step

1. Check first whether your variety is a cordon or a bush.Only cordon (indeterminate) varieties are side-shooted. On a bush or tumbling variety the side shoots carry most of the crop, and removing them removes the harvest. If the label does not say, a plant that keeps growing upward past a metre is a cordon.
2. Find the leaf joints on the main stem.Work up the stem and find where each leaf stalk leaves it. That junction — the armpit between the leaf and the stem — is the only place a side shoot ever grows.
3. Identify the side shoot in that armpit.It rises at roughly forty-five degrees out of the angle, and once it is a few centimetres long it has its own miniature tomato leaves. It is a whole new plant starting.
4. Confirm what you are not touching.The leaf itself comes off the stem horizontally and has no flowers. The truss comes off the stem between two leaf joints, has no leaves on it at all, and ends in a string of small yellow star-shaped flowers. That is your crop.
5. Snap the shoot out sideways with finger and thumb.Take hold of it near the base and bend it sharply to one side. A young shoot pops out cleanly and the wound closes over in a day. Do it in the morning so the wound dries during the day.
6. Use a clean knife or snips only if it has got away from you.A shoot longer than your thumb tears rather than snaps, and leaves a wound that botrytis can enter. Cut it flush and do it on a dry day. Wipe the blade between plants.
7. Go round every plant weekly, all season.Shoots appear faster in warm weather and faster still after you take the growing tip out. A weekly circuit takes two minutes and keeps every shoot small enough to snap.
8. Tie the main stem in as it grows.A side-shooted cordon puts all its weight into one stem, which will snap in wind or under a heavy truss. Tie loosely to a cane or twist round a string every 20–30cm.

Tips

• Side shoots root very easily. Push a healthy one into a pot of damp compost and you have a free extra plant — worth doing in early summer, when there is still season enough for it to crop.
• A shoot that appears right underneath a flower truss is still a side shoot; it is growing from the leaf joint just below, not from the truss.
• If a plant loses its growing tip to damage, let one strong side shoot take over as the new leader instead of starting again.
• Grafted plants sometimes throw shoots from below the graft union. Remove those completely — they are the rootstock and will never fruit usefully.

Common mistakes

• Pinching out flower trusses by mistake — The truss is the crop. Once removed there is no replacing it, and the plant simply moves on to the next one, costing you several weeks of fruit.
• Side-shooting a bush variety — Determinate varieties fruit on their side branches. Stripping them leaves a single stem with one or two trusses and a fraction of the crop.
• Leaving shoots until they are 20cm long — By then the plant has spent real energy on them, and removing them leaves a large wound in exactly the humid conditions botrytis needs.

Questions people ask