Tomato side shoots and pruning: what to remove?
Side shoots are the growths in the leaf joints: on single-stem varieties pinch them out while small, each time you water, and stop the plant two leaves above the fourth truss outdoors or above the seventh under cover. On bush varieties leave those shoots, because they carry the fruit.
By region
| North | Centre | South | |
|---|---|---|---|
| Side shoots | From planting out in May–June, and only on single-stem varieties. | From planting out in April–May. | From planting out in April. Under cover you carry on for longer. |
| Stopping | Outdoors, two leaves above the fourth truss. Under cover, above the seventh. | The same limits. | The same limits: a longer season is not a reason to leave more trusses outdoors. |
Planting-out dates are from the tomato guide. Truss limits are from the RHS, the same from north to south.
April, May and June are the planting-out months in when to plant tomatoes. The same numbers hold in the south: four outdoors, seven under cover.
Where they grow
A side shoot starts in the joint between a leaf and the stem, not at the tip and not on the flower truss. On tall, single-stem varieties the RHS removes all of them, so the plant stays upright, ties to a stake and puts its effort into fruit. Leave them, and within a few weeks you have a tangle of stems, hard to support and poor in fruit.
On bush varieties those shoots are the plant: leave them. If a loaded branch bends, give it a short cane. Don't prune it. Check the packet: if it says bush or determinate, don't pinch out the side shoots.
How to pinch, and when to stop
Snap them off with your fingers as soon as you see them, every time you water. The RHS says to pinch or snap them while they are small. A shoot that is already long can still come off, but the wound is larger: better not to get there.
Take the tip out two leaves above the last truss you want to keep: four outdoors, seven under cover, once the plant has reached its support or has set those trusses. The two leaves above the truss stay, and they shade the fruit. University of Minnesota Extension describes a pale patch on fruit left in full sun: so, while you pinch side shoots, don't strip the canopy. Rot on the tip, instead, is the water: see blossom end rot.
Lower leaves and air
Leaves that touch the soil stay wet and hold damp against the stem. Taking them off, once the plant is tall, lets air move. Don't empty the canopy: fruit in direct sun scorches. Water the soil, not the leaves, as in watering. Late blight, which is a different blotch, is in the guide under pests and diseases.
In the app
The photo check lets you snap a plant and get an indication of its health. It is only an indication, not a firm diagnosis: for serious cases, ask a professional.
Frequently asked questions
Do I remove side shoots on every plant?
Only on single-stem varieties, the ones that grow tall. On bush varieties the side shoots carry the fruit, so leave them.
How small should they be?
Snap them off as soon as you see them, with your fingers, each time you water. A long shoot can still come off, but the wound is larger.
How many trusses do I leave?
The RHS says four outdoors and seven under cover, then stop two leaves above the top truss. That holds in the north and in the south.
Can I keep two stems?
The RHS grows a single-stem variety on one stem. A second stem is a side shoot you let grow: it takes space and needs its own support.
Should I remove the lower leaves?
Ones that touch the soil, yes, so air can move. Don't strip the canopy: fruit in direct sun scorches.