What suckers are and why you remove them
Suckers are shoots that grow in the joint between the main stem and a branch — the spot where they meet at an angle. They look like new stems sprouting sideways from the plant. Left alone, they grow into full branches that produce leaves and flowers but steal energy from the fruit-bearing parts of the plant. Removing them, called suckering, directs that energy into fewer but larger tomatoes.
Not all tomato varieties need suckering. Determinate (bush) tomatoes stop growing at a set height and produce most of their fruit at once, so suckering them usually hurts more than it helps. Indeterminate (vining) tomatoes grow all season and benefit from suckering because it keeps them manageable and pushes energy into fruit instead of endless foliage.
The difference matters: if you sucker a bush tomato, you remove branches that would have flowered, and you get fewer tomatoes overall. If you don't sucker an indeterminate plant, it becomes a tangled mess that shades its own fruit and takes longer to ripen what it does produce.
Key Takeaways
- Suckers are shoots growing from the angle between the main stem and branches; removing them directs energy to fruit on indeterminate (vining) tomatoes.
- Bush tomatoes should not be suckered because the removed branches would have flowered and produced fruit.
- Remove suckers when they are small — under 4 inches long — by pinching them off by hand or cutting them with clean pruners.
- Sucker your indeterminate tomatoes every one to two weeks during the growing season, starting when the plant is about 12 inches tall.
- Stop suckering about four to six weeks before your first expected frost so the plant can finish ripening its remaining fruit.
How to identify suckers on your plant
Suckers grow at a narrow angle — usually 30 to 45 degrees — where a branch meets the main stem. The main stem grows straight up. Branches grow out at wider angles. A sucker is the shoot in between, and it will grow upward at that tight angle if you leave it.
Early in the season, when your plant is young, suckers are straightforward to spot because there are fewer branches. As the plant grows, the canopy gets denser and suckers hide among the leaves. Check the lower and middle sections of the plant first — that is where they appear most often. Once you know what to look for, you will spot them quickly.
Do not confuse a sucker with a branch. A branch grows directly from the main stem at a wide angle and will have flowers or fruit on it. A sucker grows from the angle between the main stem and an existing branch. If you are unsure, leave it alone for a few days and watch where it grows — a sucker will angle upward, while a branch will stay where it is.
When and how to remove suckers
Remove suckers when they are small — ideally under 4 inches long. At that size they snap off easily by hand, and the plant heals faster. If a sucker gets larger than 6 inches, use clean pruners to cut it off rather than tearing it, which can damage the stem.
Pinch or cut as close to the base as you can, right at the angle where the sucker meets the stem. Do not leave a stub. If you leave even a small piece, the sucker will often regrow from that spot, and you will be removing it again in a week.
Sucker your indeterminate tomatoes every one to two weeks during the growing season. Start when the plant is about 12 inches tall and has its first set of branches. Early, regular removal is easier than waiting until suckers are thick and woody. Wear gloves if your skin is sensitive — tomato plants are sticky and can irritate some people.
When to stop suckering
Stop removing suckers about four to six weeks before your first expected frost date. At that point, the plant needs all the foliage it can get to shade and ripen the fruit already on the vine. Removing suckers late in the season slows ripening and can leave green tomatoes on the plant when frost arrives.
If you live in a warm climate where frost does not arrive until late fall or winter, stop suckering in late August or early September. The exact date depends on your location and your tomato variety, but the rule is the same: give the plant time to finish its work before cold weather stops growth.
Tools and technique for clean removal
For small suckers, your fingers are the best tool. Pinch the sucker between your thumb and forefinger and snap it off with a quick motion. This works well for suckers under 4 inches and causes minimal damage to the plant.
For larger suckers or if you prefer not to use your hands, use pruning shears or a sharp knife. Sterilize the blade with rubbing alcohol or a 10 percent bleach solution (one part bleach to nine parts water) before you start, and wipe it clean between cuts if you are removing many suckers. This prevents spreading disease from one plant to another.
Make a clean cut right at the base of the sucker, flush with the main stem. Do not leave a stub or a ragged edge. A clean cut heals faster and is less likely to become infected or to regrow.
Indeterminate vs. determinate — which tomatoes to sucker
Indeterminate tomatoes grow tall and vine-like all season long. They produce flowers and fruit continuously from spring until frost. These are the tomatoes that benefit most from suckering. Examples include 'Brandywine', 'Sungold', 'Cherokee Purple', and most heirloom varieties. If your tomato plant is still growing taller in mid-August, it is almost certainly indeterminate.
Determinate tomatoes are bush varieties that reach a set height — usually 3 to 4 feet — and stop growing. They produce most of their fruit in a short window, usually over two to four weeks. Examples include 'Roma', 'San Marzano', 'Mountain Magic', and most paste tomatoes bred for canning. Do not sucker these plants. The branches you remove would have flowered and produced fruit, and you will end up with fewer tomatoes overall.
If you are not sure which type you have, check the seed packet or plant label. It will say "determinate" or "indeterminate", or use the words "bush" or "vining". If you cannot find that information, wait and watch — if the plant keeps growing taller and producing new flowers in late summer, it is indeterminate and will benefit from suckering.
Common mistakes and how to avoid them
The most common mistake is suckering a determinate (bush) tomato. This removes branches that would have produced fruit, and you end up with fewer tomatoes. Check your plant label or seed packet before you start suckering.
Another mistake is waiting too long to remove suckers. A large, woody sucker is harder to remove cleanly, heals more slowly, and can regrow. Remove them when they are small and tender.
Some people remove too much foliage at once, stripping the plant bare. This stresses the plant and can expose fruit to sunscald. Remove only the suckers — the shoots in the angles between branches and the main stem. Leave all the branches and their leaves alone.
Finally, do not sucker late in the season. If you remove suckers in September or October, the plant does not have time to grow new foliage to shade and ripen the remaining fruit. Stop suckering four to six weeks before your first frost.
Frequently Asked Questions
Do I have to sucker my tomato plants?
No, but indeterminate tomatoes produce larger fruit and ripen faster if you do. Bush tomatoes should not be suckered at all. If you have an indeterminate plant and do not sucker it, you will get more tomatoes overall, but they will be smaller and take longer to ripen because the plant is putting energy into foliage instead of fruit.
What happens if I remove a sucker by mistake and it grows back?
It will grow back, usually within a week or two. straightforward remove it again. If the same spot keeps producing suckers, cut as close to the base as possible and it will eventually stop. Do not worry — you have not damaged the plant.
Can I use the suckers I remove for anything?
Yes. Tomato suckers can be rooted in water or moist soil and grown into new plants. Place a sucker in a glass of water on a sunny windowsill and roots will form in one to two weeks. Once roots are half an inch long, plant it in soil. This is a free way to grow more tomato plants from a variety you like.
Should I sucker my tomato plant if it is stressed or diseased?
No. Wait until the plant recovers. Suckering removes foliage and stresses the plant further. If your tomato has yellowing leaves, wilting, or spots, hold off on suckering until the plant is healthy again. Once it recovers, you can resume your regular suckering schedule.
What is the best time of day to sucker tomatoes?
Early morning is best, after the dew has dried but before the heat of the day. The plant is less stressed, and the wounds heal faster. Avoid suckering in the hottest part of the afternoon or when the plant is wilted from heat or drought.