Quick Answer
To prune tomato plants, focus mainly on removing suckers, low leaves touching the soil, and dead or diseased growth. For indeterminate tomatoes, remove small suckers growing between the main stem and leaf branches, while keeping one or two main stems depending on your support system. Determinate tomatoes need much less pruning because their branches produce a large portion of the crop; aggressive pruning can reduce yield.
What You Need Before Pruning
You usually need only:
- Clean hands
- Sharp hand pruners or scissors for larger shoots
- Soap and water or rubbing alcohol for cleaning tools
- A dry day for pruning
- A way to identify whether your tomato is determinate or indeterminate
Check the seed packet, plant tag, or variety description if you are unsure. Determinate tomatoes are generally compact and bushy and produce their crop over a relatively concentrated period. Indeterminate tomatoes continue growing and producing flowers and fruit throughout the season.
1. Identify Whether Your Tomato Is Determinate or Indeterminate
This is the most important decision before you start cutting.
Indeterminate tomatoes
Indeterminate varieties continue producing new stems, leaves, flowers, and fruit as long as growing conditions allow. They can become tall and crowded, so selective pruning is particularly useful when the plants are staked, trellised, or grown on a string.
For these plants, gardeners commonly remove suckers and train the plant to one or two main stems. This can improve airflow and make the plant easier to support and manage.
Determinate tomatoes
Determinate varieties naturally stop growing after reaching their mature size. Their branches contribute significantly to the crop, so heavy pruning can remove potential fruit-producing growth.
Some extension recommendations allow limited sucker removal, particularly below the first flower cluster, while others recommend leaving determinate plants largely unpruned except for foliage touching the ground or clearly unhealthy growth. The practical takeaway is to avoid aggressive pruning of determinate plants.
If your seed packet says determinate, think “light pruning.” If it says indeterminate, you have more reason to manage suckers and stems.
2. Find the Suckers
The most important growth to recognize when learning how to prune tomato plants is the sucker.
A sucker is a new side shoot that develops in the angle between the main tomato stem and a leaf branch. When allowed to grow, it can become a large branch with its own leaves, flowers, and fruit.
Look at the junction where a leaf branch meets the main stem. If you see a small shoot emerging from that V-shaped joint, that is usually the sucker.
When should you remove tomato suckers?
For indeterminate plants, remove unwanted suckers while they are still small. Small shoots can usually be pinched off with your fingers, while larger ones can be cut with clean pruners. Removing them early also avoids having to make larger cuts later.
Do not automatically remove every side shoot simply because it is growing. First decide how many main stems you want.
3. Choose One or Two Main Stems
For an indeterminate tomato, you can train the plant to one or two main stems.
One-stem system
If you want a narrow, easy-to-manage plant, keep the main stem and remove the other suckers as they develop.
This approach works particularly well when the plant is being trained vertically on a stake or string.
The trade-off is important: a heavily pruned, single-stem plant generally has fewer fruit-producing stems. UC guidance notes that plants with two or more stems can produce more tomatoes and provide better foliage protection from intense sunlight, while a single-leader plant may produce earlier fruit but with lower total yield.
Two-stem system
For a two-stem plant, keep the main stem plus a strong sucker near the first flower cluster. Remove the other unwanted suckers.
This gives the plant another fruit-producing stem without allowing every sucker to develop into a large branch. Several extension recommendations describe this as a practical pruning system for indeterminate tomatoes.
4. Remove Suckers Correctly
Once you have decided which stems to keep, remove the unwanted suckers.
Small suckers
If a sucker is only a small shoot, pinch it between your fingers and snap it away cleanly.
Larger suckers
If the sucker has become thick or difficult to remove by hand, use sharp, clean pruning shears.
Make a clean cut rather than tearing or crushing the stem. Large pruning wounds take longer to heal and can increase opportunities for pathogens to enter the plant.
A simple routine
Check indeterminate plants regularly during active growth. New suckers can continue appearing throughout the season, so pruning is not necessarily a one-time job.
Common mistake: removing a promising main branch simply because it looks like a sucker. Always trace the shoot back to its point of origin before cutting.
5. Remove Low Leaves and Foliage Touching the Soil
Suckers are not the only growth you can remove.
Leaves and branches that touch or sit very close to the soil can increase contact with soil splashes and make the lower part of the plant harder to keep dry and clean. Extension guidance recommends removing low foliage, particularly on indeterminate plants, while maintaining enough healthy foliage to protect developing fruit.
Start with:
- Leaves touching the ground
- Lower leaves that are yellowing or clearly dying
- Diseased leaves
- Crowded foliage that prevents reasonable airflow
Do not strip the entire lower half of the plant simply to make it look tidy.
A useful guideline from Iowa State Extension is to remove foliage from roughly the bottom 6–12 inches when appropriate, particularly foliage close to the soil, while avoiding removal of more than about one-third of the plant’s foliage at once.
6. Prune Tomato Plants While They Are Fruiting
You can prune an indeterminate tomato plant after it has started flowering and producing fruit. In fact, sucker management is normally performed throughout the active growing season.
The important point is that fruiting does not mean you should remove everything around the tomatoes.
Leaves are important because they produce energy for the plant and help shade developing fruit. Avoid removing healthy leaves simply because they are near a tomato.
When pruning a fruiting plant:
- Remove unwanted suckers.
- Remove leaves touching the soil.
- Remove yellow, dead, or diseased foliage.
- Open excessively crowded areas selectively.
- Keep healthy leaves around fruit clusters.
- Continue supporting the stems as they grow.
University of Vermont guidance specifically recommends being careful not to remove the leaves immediately above and below a fruit cluster because those leaves provide shade and contribute sugars to the developing fruit.
Common mistake: exposing green tomatoes to intense direct sunlight by removing too much foliage. Excessive pruning can increase the risk of sunscald.
7. Remove Dead, Damaged, or Diseased Growth
Not every pruning cut is about controlling plant shape.
Dead, damaged, and diseased leaves should be removed when noticed. Diseased foliage should be handled carefully so you do not spread pathogens to healthy plants.
Clean your hands and pruning tools when moving between plants, especially when working with plants showing disease symptoms. Iowa State, Wisconsin, and UC guidance all emphasize sanitation because contaminated hands and tools can spread plant diseases.
If you remove clearly diseased material, do not automatically put it into your home compost. Local extension guidance recommends disposing of diseased tomato material rather than composting it.
8. Improve Airflow Without Stripping the Plant
One reason gardeners prune tomatoes is to reduce excessive crowding.
A dense canopy can trap humidity and slow drying after rain or watering. Selectively removing unwanted shoots and some crowded foliage can improve airflow through the plant.
But airflow does not mean an almost leafless plant.
Think of pruning as opening the canopy, not removing the canopy.
If you can see healthy leaves distributed throughout the plant and air can move through crowded areas, there may be no reason to keep cutting.
UC IPM also cautions that severe pruning to a single stem can substantially reduce total crop production and may increase certain disease or fruit-disorder problems.
9. Stop Pruning Before You Remove Too Much Foliage
One of the easiest tomato-pruning mistakes is continuing to cut simply because the plant still looks crowded.
A tomato needs substantial healthy foliage to support fruit development and protect fruit from excessive sunlight.
Wisconsin guidance recommends stopping routine pruning about one to two weeks before the expected first harvest so the plant has time to develop a canopy that protects the fruit from sunscald.
Near the end of the season, however, indeterminate plants may be topped when gardeners need to stop further vertical growth or concentrate on existing fruit. University of Vermont recommends removing growing tips about a month before expected frost in suitable situations so the plant stops putting energy into new flowers and fruit.
These are different jobs: routine sucker pruning controls growth during the season, while late-season topping is a specific strategy for managing an indeterminate plant as the season ends.
When Not to Prune Tomato Plants
There are several situations when pruning should be reduced or avoided.
When the plant is wet
Avoid routine pruning when tomato foliage is wet. Maryland Extension guidance specifically advises against pruning wet plants because wet conditions can favor the spread of bacterial diseases during pruning.
Wait until the foliage has dried.
When you are dealing with a determinate variety
Do not apply an aggressive indeterminate-style pruning system to a determinate plant. Removing too many branches can remove potential fruit production.
When the plant is already heavily pruned
If your tomato has very little healthy foliage remaining, stop cutting. The goal is not to make the plant as open as possible.
During extreme heat or intense sun
Be especially conservative with foliage removal during periods of intense sunlight. Healthy leaves help shade fruit, and excessive exposure can contribute to sunscald.
When there is no clear reason for the cut
Tomatoes do not need to be pruned simply because a branch exists.
If a healthy branch is contributing useful foliage and fruit and is not causing a management problem, leaving it alone is a legitimate option. Tomato plants can produce good crops without pruning.
What Part of the Tomato Plant Do You Cut Off?
For most pruning jobs, you are removing specific growth rather than cutting the main plant back randomly.
The parts you may remove include:
| Plant part | Usually remove? | Why |
|---|---|---|
| Small unwanted suckers | Yes, mainly on indeterminate plants | Controls excess stems and improves manageability |
| Leaves touching soil | Yes | Keeps lower foliage away from soil contact |
| Yellow/dead leaves | Yes | Removes declining tissue |
| Diseased leaves | Yes | Helps remove infected tissue and reduce spread |
| Crowded leaves | Selectively | Improves airflow |
| Healthy leaves near fruit | Usually no | Supports fruit and provides shade |
| Main stem | Usually no | It is a primary fruit-producing structure |
| Fruit-producing branches on determinate plants | Usually no | Removing them can reduce yield |
The most important cut for an indeterminate tomato is usually the removal of an unwanted sucker at a leaf axil rather than cutting the main stem.
Common Tomato Pruning Mistakes
1. Pruning every sucker
Removing every sucker is not automatically better.
Every sucker can potentially become a fruit-producing branch. Heavy pruning can reduce the total crop, so choose a training system instead of removing growth indiscriminately.
Fix: Decide whether you want one, two, or more productive stems and remove only the growth that conflicts with that plan.
2. Treating determinate and indeterminate tomatoes the same
This is one of the biggest mistakes beginners make.
Determinate plants have a naturally limited growth habit and can lose productive branches when heavily pruned. Indeterminate plants continue producing new growth and generally offer more opportunity for sucker management.
Fix: Check the variety before pruning.
3. Removing too many leaves
A plant with excellent airflow but almost no leaves is not the goal.
Fix: Keep a healthy canopy, particularly around developing fruit.
4. Cutting large suckers too late
Large shoots require larger cuts than small suckers.
Fix: Inspect indeterminate plants regularly and remove unwanted suckers while they are small.
5. Pruning wet plants
Wet conditions can increase the risk of spreading bacterial pathogens during pruning.
Fix: Wait for the foliage to dry and clean your hands and tools.
6. Exposing tomatoes to too much direct sun
Removing large amounts of foliage can expose fruit that was previously shaded.
Fix: Keep enough healthy leaves around developing fruit to provide protection from strong sunlight.
7. Cutting without identifying the stem
A beginner may see a vigorous shoot and assume it is a sucker.
Fix: Trace each shoot back to the main stem and check exactly where it originates before cutting.
Troubleshooting Tomato Pruning Problems
The plant keeps producing lots of new shoots → It is probably indeterminate
Indeterminate tomatoes naturally continue producing new suckers and stems during the growing season.
Solution: Inspect the plant regularly and remove unwanted suckers according to your one- or two-stem training system.
The plant looks bare after pruning → Too much foliage was removed
A very open plant is not necessarily healthier.
Solution: Stop pruning and allow new foliage to develop. Avoid further unnecessary leaf removal, especially during strong sunlight.
Tomatoes are getting pale or damaged on exposed sides → Too much direct sun
Fruit normally benefits from foliage that provides some shade.
Solution: Avoid excessive leaf stripping and maintain a healthy canopy around fruit clusters.
The plant produces fewer tomatoes after heavy pruning → Too many productive branches were removed
Suckers and side branches can produce flowers and fruit. Severe pruning can therefore reduce total production.
Solution: Use selective pruning rather than trying to remove every side shoot.
Frequently Asked Questions
Should I prune tomato plants once they start flowering?
Yes, indeterminate tomatoes can continue to be selectively pruned after flowering begins. Remove unwanted suckers and unhealthy or low foliage while keeping healthy leaves around developing fruit.
Should I remove the leaves below the first tomatoes?
Lower leaves that touch or are very close to the soil can be removed. However, do not strip the plant unnecessarily; healthy foliage still contributes to the plant and helps protect fruit.
Should I prune determinate tomato plants?
Usually only lightly. Avoid the aggressive sucker removal used for many indeterminate plants because determinate plants depend on their branches for much of their crop.
Can I prune tomato plants with fruit on them?
Yes. Remove unwanted suckers, dead or diseased leaves, and foliage touching the soil. Keep healthy leaves around fruit clusters rather than stripping them away.
How often should I prune indeterminate tomatoes?
Check them regularly during active growth because new suckers continue to appear. Some extension guidance recommends follow-up pruning roughly every 10–14 days when needed, while other systems rely on more frequent inspection and removal of small suckers as they appear.
Is pruning tomatoes necessary?
No. Tomatoes can grow and produce without pruning. Pruning is mainly a management technique for controlling growth, improving access and airflow, and fitting plants to their support system.
Conclusion
Successful tomato pruning is mostly about selective removal, not cutting the plant back as much as possible. Identify the variety first, remove unwanted suckers from indeterminate plants, keep soil-level and diseased foliage under control, and preserve enough healthy leaves to shade and feed the developing fruit.
Before making each cut, ask one simple question: Is this growth causing a real problem, or is it still helping the plant produce and protect fruit?
