The main pruning spots on a tomato plant
Prune suckers — the shoots that grow between the main stem and branches — and remove the lowest leaves once the plant is established. On indeterminate varieties (the tall ones that keep growing all season), pinch off the top 4 to 6 inches about 4 to 6 weeks before your first frost date to redirect energy into ripening fruit instead of new growth. On determinate varieties (the compact, bush types), pruning is lighter — remove only dead leaves and the lowest branches that touch soil.
The goal is airflow and light penetration. Leaves that stay wet or sit in shade invite disease and slow ripening. Removing 20 to 30 percent of foliage is usually safe; removing more than that stresses the plant and exposes fruit to sunscald.
Key Takeaways
- Suckers — shoots between the main stem and branches — should be removed on indeterminate tomatoes to channel energy into fruit, but determinate varieties need minimal pruning.
- Remove the lowest leaves once the plant reaches 12 inches tall to prevent soil-borne disease from splashing onto foliage.
- Pinch the growing tip 4 to 6 weeks before your first frost date on tall varieties so the plant stops making new flowers and ripens what it already has.
- Never remove more than 30 percent of the plant's foliage at once, and always use clean pruners or your fingers to avoid spreading disease.
Removing suckers on indeterminate tomatoes
Indeterminate tomatoes grow as a single main stem with branches coming off at angles. Where the branch meets the main stem, a small shoot — the sucker — will emerge. Pinch this off with your fingers when it is 1 to 2 inches long, or cut it with pruners if it has hardened. Do this every 7 to 10 days during the growing season.
Removing suckers does not harm the plant; it straightforward keeps the energy focused on the branches that are already there and the fruit they carry. A plant left unpruned will produce more flowers but smaller fruit and slower ripening, because the plant is spreading its resources too thin.
On determinate varieties, suckers are less of a problem because the plant naturally stops growing at a set height. You can remove a few if the plant looks crowded, but it is not necessary.
Cutting off the lowest leaves
Once your tomato plant is 12 inches tall, remove all leaves within 6 to 8 inches of the soil. These leaves are most likely to pick up fungal spores from soil splash during watering or rain. Diseases like early blight and septoria leaf spot start on lower foliage and work their way up.
Remove these leaves gradually over a week or two rather than all at once. Use clean pruners or pinch them off by hand. If you see any yellowing, spotting, or wilting on lower leaves, remove them when ready — do not wait.
Continue removing lower leaves throughout the season as the plant grows taller. By mid-summer, the lowest 12 to 18 inches of the plant should be bare stem.
Topping the plant before frost
About 4 to 6 weeks before your area's first frost date, pinch or cut off the top 4 to 6 inches of the main stem on indeterminate tomatoes. This stops the plant from making new flowers. Any flowers that form after this point will not have time to ripen before cold arrives, so removing them lets the plant pour energy into the fruit already on the vine.
You can find your first frost date through your local cooperative extension office or by searching "[your city] first frost date." If your first frost is October 15, for example, top the plant around September 1 to September 15.
Determinate tomatoes do not need topping because they stop growing naturally. If you grow them, focus on removing diseased or damaged leaves instead.
Pruning damaged or diseased branches
Remove any branch that shows yellowing leaves, dark spots, wilting, or soft spots on the stem. Cut the branch off at its base where it meets the main stem. If the damage is only on part of a branch, you can cut just that section, but make the cut above a healthy leaf node.
Disinfect your pruners between cuts by wiping the blade with rubbing alcohol or a 10 percent bleach solution (one part bleach to nine parts water). This prevents you from spreading disease from one branch to another.
If you see a branch that is rubbing against another or blocking light from reaching fruit below, remove it. Branches that cross or tangle also trap moisture and invite fungal growth.
When not to prune
Do not prune during the hottest part of the day or when the foliage is wet. Pruning wet plants spreads disease faster. Wait until morning after the dew dries or late afternoon when temperatures are dropping.
Do not prune more than 30 percent of the plant's foliage in a single week. The plant needs leaves to photosynthesize and produce energy for fruit. Aggressive pruning stresses the plant and can cause sunscald on exposed fruit.
Avoid pruning in the first 3 to 4 weeks after transplanting. Let the plant establish roots and recover from transplant shock before you start removing foliage.
Tools and cleanup
Use sharp pruners — bypass pruners work better than anvil pruners for tomato stems. Dull blades crush tissue and invite disease. Pinching suckers with your fingers works fine if they are still soft; save the pruners for thicker branches.
Remove all pruned material from the garden bed and dispose of it in the trash or a hot compost pile (one that reaches 140°F or higher). Do not leave clippings on the ground where disease spores can spread to healthy plants. If the clippings show any sign of disease, throw them away rather than composting.
Frequently Asked Questions
Should I prune cherry tomatoes and heirloom varieties differently?
Cherry tomatoes are usually indeterminate, so treat them like tall varieties — remove suckers and top before frost. Heirlooms vary; check whether yours is determinate or indeterminate. If you are unsure, prune lightly — remove only dead leaves and the lowest foliage. You can always prune more next week if the plant looks crowded.
Can I prune tomatoes in late summer?
Yes, but be cautious. Light pruning of dead or diseased leaves is fine. Heavy pruning in August or September can expose fruit to sunscald and reduce the plant's ability to ripen what is already there. Focus on removing only what is clearly damaged or diseased.
What if I accidentally remove too much foliage?
The plant will recover, but growth will slow for a week or two. Water consistently and avoid fertilizing until you see new leaf growth. In the future, remove no more than 30 percent of the foliage at once and spread pruning over several days rather than doing it all in one session.
Do I need to seal pruning cuts with wound dressing?
No. Tomato plants heal quickly on their own, and wound dressing can trap moisture and invite disease. Leave the cut open to air. If the cut is large or the plant looks stressed, hold off on more pruning for a few days.
Can I prune suckers and use them to start new plants?
Yes. Place sucker cuttings in water or moist soil, and they will root in 1 to 2 weeks. You can then pot them up and grow them as new plants. This works well for heirloom varieties you want to propagate, but remember that hybrid tomatoes grown from seed will not produce identical offspring.