What Suckering Does and Why You Should Do It

Suckering means removing the small shoots that grow between the main stem and branches of a tomato plant. These shoots, called suckers, will grow into full branches if left alone, turning your plant into a dense tangle that shades the fruit and splits the plant's energy between too many stems. Removing them directs the plant's strength into fewer, larger fruit and improves air flow so disease spreads less easily.

Not every tomato plant needs suckering. Determinate varieties (bush types that grow to a set size and stop) rarely benefit. Indeterminate varieties (vining types that grow all season) are where suckering makes the biggest difference. If you grow indeterminate tomatoes and want fruit the size you see in farmers markets rather than golf balls, suckering is worth the five minutes per week it takes.

Key Takeaways

  • Suckers are small shoots growing between the main stem and branches; removing them lets the plant put energy into fewer, larger fruit.
  • Indeterminate (vining) tomatoes benefit most from suckering; determinate (bush) varieties rarely need it.
  • Start suckering when suckers are small and tender, ideally when they are 2 to 4 inches long, so you can pinch them off by hand.
  • Sucker your plants once a week during the growing season, focusing on the lower half of the plant first.
  • Stop suckering in late summer so the plant can focus on ripening fruit already on the vine rather than growing new branches.

When to Start Suckering and How to Spot a Sucker

Begin suckering when your plant is about 12 inches tall and has its first true leaves. At this stage, suckers are small and straightforward to remove. A sucker grows at the angle where a branch meets the main stem—it looks like a tiny shoot trying to become a branch. The main stem runs straight up the center; branches come off at wider angles. A sucker sits in the narrow V between them.

The easiest way to tell a sucker from a legitimate branch is location and size. Branches grow from the main stem at regular intervals as the plant grows taller. Suckers appear in the angles between the main stem and those branches. Early in the season, suckers are soft and thin. Later, they harden and thicken, making them harder to remove cleanly. This is why catching them young matters—a 2-inch sucker pinches off with your thumb and forefinger; a 6-inch sucker needs pruning shears and leaves a wound.

How to Remove Suckers by Hand

The best time to sucker is early morning when the plant is firm and full of water. Grasp the sucker as close to the main stem as you can reach, then bend it backward and pinch it off with your thumb and forefinger. The sucker should snap cleanly. If it bends without breaking, it is too woody—use pruning shears instead, cutting as close to the stem as possible without damaging the bark of the main stem.

Work from the bottom of the plant upward. Remove all suckers from the lower 12 inches first, then move up. Leave the top 6 to 12 inches of the plant alone—those upper branches are still developing and removing them will slow fruit production. On a mature indeterminate plant, you may remove 10 to 20 suckers per week during peak growing season. This sounds like a lot, but each one takes three seconds.

Wash your hands or wipe your pruning shears with a cloth between plants if you are working in a garden with multiple tomatoes. Tomato diseases like early blight and septoria leaf spot spread on tools and hands. A quick wipe with a dry cloth is enough; you do not need bleach for routine suckering.

Common Mistakes That Waste Your Effort

The most common mistake is removing too much. Some gardeners remove every sucker and end up with a single thin stem that cannot support the fruit load. The goal is not a bare stick—it is a plant with 3 to 5 main stems that are strong enough to hold heavy fruit. If you remove a sucker and the plant looks noticeably thinner, you removed too much.

Another mistake is waiting too long. A sucker that has grown to 8 inches and hardened off will leave a wound when you remove it, and that wound is an entry point for disease. Sucker weekly so you catch them small. If you miss a week and find large suckers, remove them anyway, but do not feel you have failed—a plant with some suckers is still better than a plant that is never suckered.

A third mistake is suckering too late in the season. In late August or early September (depending on your climate), stop suckering and let the plant focus on ripening the fruit already on the vine. Removing suckers in September forces the plant to grow new branches when it should be finishing fruit. Your last suckering should happen about six weeks before your first frost date.

Suckering Versus Pruning: What Is the Difference

Suckering and pruning are related but different. Suckering removes small shoots before they become branches. Pruning removes entire branches or the top of the plant to control size or shape. You can sucker without pruning, but if you prune, you are usually also suckering the regrowth that follows.

For most home gardeners, suckering alone is enough. You do not need to prune the top of the plant or remove branches unless the plant is so dense that air cannot move through it, or unless you are trying to fit it into a very small space. If your plant is healthy and you sucker weekly, pruning is optional.

Tools You Need and When to Use Them

For small suckers (under 4 inches), your fingers are the best tool. Pinching off a tender sucker is faster than finding shears and causes less damage. For suckers that have hardened or are longer than 4 inches, use sharp pruning shears or a pruning knife. Dull shears crush the stem instead of cutting cleanly, which invites disease.

Keep one pair of shears dedicated to tomatoes if you can, or wipe the blades with a dry cloth between plants. A small hand pruner costs $10 to $20 and will last years. Bypass pruners (the kind with two blades that pass each other) work better than anvil pruners (the kind with one blade that presses down onto a flat surface) for tomato work because they make a cleaner cut.

How Often to Sucker During the Growing Season

Once a week is the standard rhythm. Walk through your tomato patch every seven days and remove all suckers that have grown since the last visit. At this pace, you catch them small and the job takes minutes. If you skip two weeks, suckers will be larger and tougher, and the job takes longer.

During the hottest part of summer, suckers may grow faster and you might need to sucker twice a week. During cool spring or fall, once a week is enough. The plant will tell you—if you see suckers that are 6 inches or longer, you are suckering less often than the plant needs.

Frequently Asked Questions

Do I have to sucker determinate tomatoes?

No. Determinate varieties are bred to grow to a set size and stop, so they naturally stay bushy and compact. Suckering them does not improve fruit size the way it does with indeterminate types. If your determinate plant is so dense that leaves are touching the soil, you can remove a few lower suckers to improve air flow, but it is not necessary.

What if I accidentally remove a main branch instead of a sucker?

The plant will recover. A tomato is tough and will grow new branches to replace it. You may lose a week or two of growth, but the plant will not die. If you are unsure whether something is a sucker or a branch, leave it alone and check it again next week—a sucker will still be there, and a branch will have grown larger.

Can I sucker cherry tomatoes?

Cherry tomatoes are usually indeterminate, so yes, you can sucker them. However, cherry tomatoes are smaller and produce so many fruit that suckering makes less difference than it does with large-fruited varieties. If you want to try it, sucker lightly—remove only the lowest suckers and leave the upper plant fuller. Heavy suckering on cherry tomatoes can reduce your total harvest.

What should I do with the suckers I remove?

Throw them in the compost if your pile gets hot enough to kill disease (above 140°F). If you are unsure, throw them in the trash instead. Do not leave them on the ground near the plant, where they can root and create new plants, or where disease spores can splash back onto the main plant during watering.

Is it okay to sucker in the rain or when leaves are wet?

It is better to wait for dry conditions. Wet leaves and stems make it easier to spread disease from plant to plant. If you must sucker when wet, wipe your hands or shears between plants with a dry cloth. Early morning after the dew dries is the ideal time.