Pruning tomatoes correctly can increase the size of individual fruits and help your plants stay healthy through the entire growing season. The key is knowing which plants to prune, where to make cuts, and when to leave growth alone. Not every tomato plant benefits from pruning, and over-pruning can actually reduce your harvest.
Know Your Tomato Type First
Before you cut anything, figure out whether you’re growing determinate or indeterminate tomatoes. This single distinction changes your entire pruning strategy.
Indeterminate tomatoes are the ones that benefit from pruning. These are the vining types that keep growing taller and producing fruit all season long. Varieties like Cherokee Purple, Brandywine, Sun Gold, and most cherry tomatoes fall into this category. Because they grow continuously, they send out side shoots (called suckers) that compete with developing fruit for the plant’s energy. Removing those suckers redirects resources into fewer, larger tomatoes.
Determinate tomatoes grow to a set height, produce most of their fruit in a concentrated window, and then stop. Pruning these plants removes branches that would have produced fruit, directly cutting into your yield. If you’re growing a paste tomato like Roma or a bush variety like Celebrity, skip the sucker removal entirely. The only pruning determinate plants need is clearing the lowest leaves off the ground, which we’ll cover below.
How to Identify and Remove Suckers
Suckers are small shoots that grow in the “axil,” the V-shaped junction where a leaf branch meets the main stem. They emerge at an angle and look like miniature versions of the main stem. When they first appear, they’re smaller and more tender than the surrounding growth, making them easy to spot if you know where to look. Every leaf junction on your plant is a potential sucker site, so check each one when you prune.
When a sucker is small (under about 2 inches), you can pinch it off cleanly between your thumb and forefinger. For larger suckers, use sharp pruners to avoid tearing the stem. If you’re moving between plants, dip your pruner blades in a solution of one part household bleach to nine parts water. This prevents spreading viral or bacterial diseases from one plant to the next.
Left alone, each sucker will develop into a full branch with its own leaves, flowers, fruit, and even secondary suckers. That sounds productive, but the tradeoff is real: the plant has to split its available energy among all those growing points. You end up with more tomatoes, but each one is smaller and may be less flavorful. Removing suckers concentrates the plant’s resources into fewer fruit on the main stems, producing larger individual tomatoes that often ripen earlier.
Simple Pruning vs. Missouri Pruning
There are two main approaches to sucker removal, and the best choice depends on your climate.
Simple pruning means removing the entire sucker at the base, leaving nothing behind. This is the most aggressive approach and works well in cooler climates or for gardeners who want the largest possible fruit. It gives the plant maximum airflow and channels the most energy into existing fruit clusters.
Missouri pruning is a gentler technique better suited to warmer regions. Instead of removing the whole sucker, you pinch off only the growing tip and leaflets at the end, leaving the two base leaflets in place. As those remaining leaves grow, they shade nearby fruit and protect it from sunscald, a common problem in hot, sunny climates where exposed tomatoes develop pale, leathery patches. You still reduce the sucker’s demand on the plant, but you keep some extra leaf cover where it matters.
Clear Lower Leaves From the Ground
Regardless of tomato type, remove all foliage within 6 to 8 inches of the soil surface. This is one of the most effective things you can do to prevent fungal diseases like early blight and septoria leaf spot.
These diseases live in the soil and spread when rain or irrigation water splashes soil particles onto low-hanging leaves. Once the fungus gets a foothold, it climbs the plant and can defoliate it by midsummer. Clearing that bottom zone creates a gap between the soil and the lowest leaves, dramatically reducing splash contact. It also improves airflow around the base of the plant, which keeps foliage drier and less hospitable to mildew and fungal growth.
When and How Often to Prune
Start checking for suckers once your transplants are established and actively growing, typically a few weeks after planting. Suckers appear quickly during warm weather, so plan to inspect your plants at least once a week. Catching suckers while they’re small causes less stress to the plant and leaves smaller wounds that heal faster.
As the season progresses, decide how many main stems you want each plant to carry. Most gardeners allow one to three stems. A single-stem plant produces the fewest but largest tomatoes and is easiest to stake or trellis. Allowing one or two suckers low on the plant to develop into secondary stems gives you more fruit without overwhelming the plant. Any suckers above those chosen stems get removed throughout the season.
Pruning is an ongoing task, not a one-time event. New suckers will keep forming at every leaf junction for as long as the plant is growing. A quick weekly pass through your tomato patch takes just a few minutes and keeps growth under control.
Late-Season Topping for Earlier Ripening
About four to six weeks before your expected first frost, cut the growing tip off each main stem. This technique, called topping, tells the plant to stop producing new flowers and foliage and instead focus its remaining energy on ripening the fruit that’s already set.
At the same time, remove any small green tomatoes that clearly won’t have time to mature. Research from North Dakota found that late-season pruning (around early September in that climate) actually increased total usable yield because plants redirected their energy into ripening existing fruit rather than setting new tomatoes that would never mature. Plants that were topped late in the season practically ripened all of their remaining fruit before the growing season ended.
Some gardeners also gently tug the base of the plant to slightly disturb the roots, which can trigger a stress response that accelerates ripening. This is an old-school technique with mixed results, but combined with topping and removing immature fruit, it’s one more tool for squeezing the last harvest out of your plants before cold weather arrives.
What Not to Cut
More pruning isn’t always better. Leaves are the plant’s solar panels. Every leaf contributes to photosynthesis, and removing too many leaves starves the plant of the energy it needs to produce and ripen fruit. A good rule of thumb is to never remove more than a third of the plant’s foliage at once.
Avoid pruning in wet conditions, as open wounds are entry points for bacterial and fungal infections. If a plant looks diseased, prune it last and clean your tools thoroughly afterward. And resist the urge to prune determinate varieties beyond clearing the lower leaves. Those compact plants have a built-in plan for fruit production, and removing branches only takes fruit-bearing wood out of the equation.