What suckers are and why you should remove them

Suckers are shoots that grow between the main stem and branches of a tomato plant. They sprout from the joints where a leaf branch meets the central stem, and they will grow into full branches if you leave them alone. Removing them directs the plant's energy into producing fruit on the main stems instead of wasting it on extra foliage that shades the fruit and slows ripening.

Not every tomato variety needs sucker removal. Determinate (bush) tomatoes naturally stay compact and produce most of their fruit at once, so removing suckers is optional. Indeterminate (vining) tomatoes grow tall all season and benefit from sucker removal because they can become dense tangles that trap moisture and invite disease. If you are growing a tall variety that you plan to stake or cage, removing suckers will give you cleaner plants with better air circulation and easier harvesting.

Key Takeaways

  • Suckers are shoots that grow in the crotch between the main stem and leaf branches, and removing them on indeterminate varieties directs energy to fruit production.
  • The best time to remove suckers is when they are small and tender, ideally 2 to 4 inches long, because they snap off cleanly and cause less damage to the plant.
  • You can pinch off small suckers by hand or use pruning shears for larger ones, but always sterilize shears between cuts to avoid spreading disease.
  • Check your plants weekly during the growing season because suckers grow quickly, and leaving them too long wastes plant energy and creates dense canopy that traps moisture.
  • Determinate bush tomatoes rarely need sucker removal, but indeterminate vining varieties benefit significantly from it.

Identifying suckers on your tomato plant

Suckers look different from regular leaf branches, and learning to spot them early makes removal easier. A sucker grows straight up from the narrow angle (called a crotch) where a leaf branch meets the main stem. It has its own small leaves and will eventually develop flowers if left alone. A regular leaf branch, by contrast, grows at a wider angle and is part of the plant's natural structure.

The easiest way to tell them apart is to look at the geometry. Pinch the area gently with your thumb and forefinger. If there is a narrow V-shaped notch between the main stem and a branch, that narrow angle is where suckers grow. The wider angles are your main fruiting branches. On a young plant, you may see suckers appearing within a week or two of planting, so check regularly even when the plant is small.

When to remove suckers during the growing season

Remove suckers when they are small and tender, ideally when they are 2 to 4 inches long. At this size they snap off cleanly with a pinch of your fingers, and the plant heals quickly with minimal stress. If you wait until they are woody and thick, removal becomes harder and leaves a larger wound that can invite disease.

Check your plants once a week during the active growing season, especially on indeterminate varieties. Suckers grow fast in warm weather—sometimes several inches in a single week. The longer you wait between checks, the more energy the plant has already spent on growth you will be removing. Weekly inspection keeps the job small and prevents the plant from becoming overgrown and shaded.

Stop removing suckers about four to six weeks before your first expected frost. At that point, the plant's energy should go into ripening the fruit already on the vine rather than healing wounds from pruning. In most climates, this means stopping sucker removal in late July or early August.

How to remove suckers by hand

For small suckers, hand removal is the fastest and least damaging method. Hold the main stem steady with one hand to keep from jostling the plant. With your other hand, grasp the sucker as close to its base as you can reach, then bend it sharply downward or to the side until it snaps off. The sucker should break cleanly at the joint.

If the sucker does not snap cleanly and instead tears or bends without breaking, stop and use pruning shears instead. A ragged break can leave a wound that invites disease. Never pull a stubborn sucker straight outward, because that can damage the main stem or tear bark. A clean snap or a clean cut is always better than a torn wound.

Wash your hands after removing suckers, especially if you notice any yellowing or spotting on the leaves. This prevents spreading disease from one plant to another if you move to a different tomato plant next.

Using pruning shears for larger suckers

If a sucker has grown woody or thick, or if hand removal leaves a ragged break, use pruning shears (also called secateurs). Make a clean cut as close to the base of the sucker as you can, cutting at a slight angle. The angled cut sheds water and heals faster than a flat cut.

Sterilize your shears before each cut if you are removing suckers from multiple plants or if you notice any disease on the plant. Wipe the blades with a cloth soaked in rubbing alcohol or a 10 percent bleach solution (one part bleach to nine parts water). Let the blades air-dry for a few seconds before cutting. This takes only a moment and prevents spreading fungal or bacterial disease from one plant to another.

Do not leave stubs. If you cut a sucker and a small stub remains, pinch it off by hand or make a second cut flush with the stem. Stubs can regrow and waste your effort.

Common mistakes that damage the plant

The most common mistake is removing too much foliage at once. Tomato plants need leaves to photosynthesize and produce energy for fruit. If you remove all the suckers plus some main branches in a single session, you can shock the plant and slow fruit production. Remove only the suckers—the shoots in the narrow crotches—and leave all the main fruiting branches intact.

Another mistake is removing suckers too late in the season. If you wait until late August or September to start removing suckers, the plant has already spent weeks growing dense foliage that shades the remaining fruit. Start early in the season when plants are young, and keep up with weekly checks. A few minutes of work each week prevents hours of work later.

Leaving ragged wounds is also a problem. A torn or crushed stem invites fungal infection, especially in humid weather. Always make clean breaks or clean cuts. If a sucker does not snap cleanly, use shears instead of forcing it.

How often to check and remove suckers

Visit your tomato plants once a week during the main growing season, from planting time through late July or early August. In hot weather, suckers can grow several inches in seven days, so weekly checks keep the job manageable. If you skip two or three weeks, you may find yourself removing large woody suckers that take more time and cause more plant stress.

Early morning is the best time to check and remove suckers. The plant is fully hydrated and less stressed by pruning. Avoid pruning during the hottest part of the day or when the foliage is wet from rain or watering, because wet plants are more prone to disease spread.

Keep a straightforward record if you grow many plants. A notebook or phone note with the plant variety and the date you last checked helps you stay on schedule. This is especially useful if you have both determinate and indeterminate varieties, because you only need to focus sucker removal on the indeterminate types.

Frequently Asked Questions

Do I have to remove suckers from every tomato plant?

No. Determinate (bush) tomatoes stay naturally compact and rarely need sucker removal. Indeterminate (vining) varieties grow tall all season and benefit from it because they become dense and shaded without pruning. Check your seed packet or plant label to see which type you have. If you are unsure, removing suckers will not hurt—it just may not be necessary.

What happens if I leave suckers on the plant?

The plant will grow bushier and produce more foliage, but the fruit will ripen more slowly because the leaves shade it. The dense canopy also traps moisture, which increases the risk of fungal disease like early blight. You will still get tomatoes, but fewer of them and later in the season.

Can I use the suckers I remove for anything?

Yes. Small tender suckers can be rooted in water or moist soil to grow new plants. Place the cut end in a glass of water on a sunny windowsill and change the water every few days. Roots usually appear within one to two weeks. Once roots are an inch long, plant the sucker in soil. This works best with suckers removed early in the season.

Will removing suckers reduce my total harvest?

No. Removing suckers on indeterminate varieties actually increases your harvest because the plant directs energy into ripening fruit on the main stems instead of growing extra foliage. The fruit that does grow will ripen faster and be easier to harvest because the plant is less dense.

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

The plant will recover, but you will lose the fruit that branch would have produced. To avoid this, remember that suckers grow in the narrow V-shaped crotch between the main stem and a leaf branch. Main branches grow at wider angles. If you are unsure, leave it alone and check again in a few days—a sucker will keep growing and become more obvious.