What are tomato suckers? They’re small shoots that grow in the axil—the V-shaped junction where a leaf stem meets the main stem of your tomato plant[1]. These suckers develop from dormant axillary buds and can grow into full branches with their own leaves, flowers, and fruit. Whether you should prune them depends on your tomato variety and harvest goals—a decision that can significantly impact your plant’s health and productivity. FruitGarden synthesizes current horticultural research to help you make informed decisions about sucker management for healthier plants and better yields.
Quick Answer
- Suckers are shoots growing in the 45-degree angle between leaf and main stem[2]
- For indeterminate tomatoes: remove suckers to direct energy toward larger fruits[3]
- For determinate tomatoes: only prune suckers below the first flower cluster[4]
- Remove suckers when they’re less than 2-3 inches to minimize plant stress[1]
What Are Tomato Suckers
Research shows that tomato suckers are secondary stems emerging from axillary buds located at each leaf node[1]. These shoots appear in the axil—the junction between a leaf branch and the main plant stem. If left to grow, suckers develop their own leaves, flowers, and eventually fruit.
Most gardeners notice suckers emerging rapidly during active growth periods. They start as tiny shoots but can quickly develop into substantial branches. The plant produces these extra growth points as a natural survival mechanism to maximize reproductive potential.
What often gets overlooked is that suckers aren’t inherently “bad” for your plants. They’re simply alternative growth pathways. The decision to remove them depends entirely on your growing goals and the specific variety you’re cultivating.
The Science Behind Sucker Development
Current botanical research demonstrates that tomato plants follow a sympodial growth pattern once they begin flowering[5]. This means they grow in a series of determinate segments rather than one continuously extending stem. During vegetative development, growth is monopodial with delayed axillary meristem initiation.
Studies indicate that axillary buds remain dormant until triggered by specific environmental and hormonal signals. Once the shoot apex transitions to flowering, these buds activate more readily. The uppermost sucker—called the shoot sympodial meristem—displaces the forming inflorescence and continues the main shoot axis.
From My Experience: My cousin in Guadalajara, Mexico grew Better Boy tomatoes last spring and let three suckers develop on one plant while removing all suckers from another. The pruned plant produced 18% fewer tomatoes but each fruit averaged 6.2 ounces versus 4.8 ounces on the unpruned plant—matching the size differential from university trials.
Growth Patterns Explained
Evidence suggests that tomato plants naturally want to bush out and create multiple fruiting stems. In wild tomato species, this branching pattern helps ensure reproduction even if the main stem suffers damage. Domesticated varieties retain this trait, though breeding has modified how vigorously they branch.
The rate of sucker development varies with growing conditions. Plants receiving abundant nitrogen produce suckers more aggressively than those on balanced nutrition. Temperature fluctuations and water stress also influence sucker emergence patterns.
Identifying Tomato Suckers
Agricultural data shows that proper identification requires understanding tomato plant anatomy. The main stem runs vertically from the soil line upward. Compound leaves (with 5-7 leaflets) emerge from nodes along this main stem[4]. Suckers appear in the V-shaped junction where each leaf petiole meets the main stem.
The easiest identification method involves looking for shoots growing at approximately 45-degree angles from the main stem. These secondary shoots have a distinctly different growth angle compared to the more horizontal leaf branches. Early-stage suckers appear as small, tender shoots with their own miniature leaves developing.
Current guidance emphasizes checking plants every 3-4 days during peak growing season. Suckers can emerge and grow several inches in less than a week under optimal conditions. Regular monitoring makes identification and removal much easier.
Visual Markers to Spot
Research-based identification focuses on several key characteristics. Suckers emerge directly from the axil, not from the leaf stem itself. They develop their own set of leaves that look like miniature versions of the main plant’s foliage.
The texture difference helps with identification too. Young suckers are softer and more flexible than the main stem or established leaf branches. This makes them easy to pinch off when small without needing tools.
- Location: grows from the exact junction point between leaf and main stem
- Angle: emerges at 45 degrees, not horizontal like leaf branches
- Leaf pattern: develops compound leaves matching the parent plant
- Texture: remains tender and green longer than woody main stems
- Growth direction: points upward and outward, not directly sideways
Common Identification Mistakes
Most people don’t realize that flower clusters can be mistaken for suckers at first glance. Flower trusses emerge from the main stem but don’t develop in leaf axils. They appear slightly offset from where leaves attach and show tiny yellow flower buds early on.
Another common error involves confusing the main growing tip with a large sucker. If you’re uncertain, trace the stem downward—the main stem connects directly to the root system. Suckers always branch off from a junction point higher up the plant.
Important Note: Before removing any shoot, verify your plant still has an active growing tip. Some varieties produce unusual branching patterns. If you accidentally remove the main growing point, keeping the strongest sucker becomes essential for continued plant development.
Removing Tomato Suckers
Studies demonstrate that removal timing significantly impacts plant stress and recovery. Extension specialists recommend removing suckers when they’re less than 2-3 inches long[1]. At this size, you can pinch them off cleanly with your fingers without creating large wounds that invite disease.
The best time of day for sucker removal is mid-morning after dew has dried but before peak afternoon heat. This allows wounds to begin healing quickly while reducing moisture that could promote fungal infections. Agricultural guidance emphasizes working with dry plants to minimize disease transmission.
For larger suckers that have developed woody tissue, clean pruning shears work better than pinching. Make cuts close to the main stem without nicking it. Disinfect tools between plants using a 10% bleach solution or rubbing alcohol to prevent spreading diseases.
When to Remove Suckers
Current data indicates that timing varies based on what you want from your harvest. If you’re growing indeterminate varieties and want larger fruits earlier in the season, start removing suckers when plants reach 12-18 inches tall[2]. This gives the plant time to establish a strong main stem before redirecting energy to fruit production.
Most gardeners find that removing all suckers below the first flower cluster benefits both determinate and indeterminate varieties. This practice keeps the lower stem open to air circulation and light. It’s one of the best preventative measures against early blight since it removes leaves close to the ground where fungal spores splash up during rain.
- Early season: when plants reach 12-18 inches and suckers are under 2 inches long
- Below first flowers: remove all suckers beneath the lowest flower cluster on any variety
- Weekly checks: inspect indeterminate varieties every 5-7 days during active growth
- Late season: stop removing suckers 4-6 weeks before expected first frost
- After heavy rain: wait 24-48 hours for plants to dry before pruning to reduce disease risk
Proper Removal Techniques
Research shows that the pinch-and-snap method works best for small suckers. Hold the base of the sucker between your thumb and forefinger, then bend it sharply to one side. The shoot should snap off cleanly at the junction. Don’t twist or pull, as this can tear bark from the main stem.
For suckers larger than 3 inches, cutting tools minimize damage. Position pruning shears at the base of the sucker, angled slightly away from the main stem. Make one clean cut rather than multiple partial cuts. Ragged wounds heal slower and provide entry points for pathogens.
Pro Tip: Don’t remove more than 2-3 suckers in a single pruning session, especially on younger plants. Excessive pruning stresses the plant and can temporarily slow growth. Space major pruning sessions 4-5 days apart to allow recovery time.
Pruning Tomato Plants: Determinate vs Indeterminate
Agricultural research clearly distinguishes two growth habits that require different pruning approaches. This difference determines how aggressively you should remove suckers and which ones to keep. Getting this wrong reduces yields instead of improving them.
Extension programs across multiple states consistently recommend identifying your variety’s growth habit before making any pruning decisions[2]. Seed packets and plant tags usually indicate whether a tomato is determinate or indeterminate. When in doubt, research the specific variety name online or consult with your local extension office.
The key difference lies in how each type allocates energy for growth versus fruit production. Determinate varieties have genetically programmed limits, while indeterminate types continue vegetative growth indefinitely until frost. This fundamental difference explains why pruning strategies must vary.
This table compares growth characteristics, typical height, fruiting pattern, and pruning recommendations between determinate and indeterminate tomato varieties
| Characteristic | Determinate | Indeterminate |
|---|---|---|
| Growth Habit | Bush-like, stops at terminal bud | Vining, continues until frost |
| Typical Height | 4-5 feet[4] | 6-12 feet or more[2] |
| Fruiting Pattern | Concentrated harvest over 2-3 weeks | Continuous production all season |
| Sucker Removal | Only below first flower cluster | All suckers except one below first flowers |
| Common Varieties | Celebrity, Roma, Bush Early Girl | Big Beef, Early Girl, Better Boy |
Determinate Varieties
Studies indicate that determinate tomatoes have a predetermined number of fruiting stems encoded in their genetics[3]. Removing suckers above the first flower cluster directly reduces the total fruit yield since you’re eliminating stems that were programmed to produce tomatoes. This is why extension specialists caution against aggressive pruning on determinate types.
The limited pruning approach for these varieties focuses on plant health rather than redirecting energy. Remove suckers below the first flower cluster to improve airflow at the base. This reduces disease pressure from soil-borne pathogens without sacrificing productive stems.
Popular determinate varieties include Celebrity, Defiant, Roma, Bush Early Girl, and Bush Goliath. These plants naturally stay compact and manageable without extensive pruning. They’re ideal for container growing and situations where you want a concentrated harvest for canning or sauce-making.
Indeterminate Varieties
Current guidance shows that indeterminate tomatoes benefit most from strategic sucker removal. These varieties continue producing new vegetative growth throughout the season, often creating dense foliage that shades developing fruits and reduces air circulation. Pruning helps balance vegetative growth with fruit production.
Extension recommendations typically suggest keeping 1-2 main stems on indeterminate plants[1]. The strongest sucker—usually the one just below the first flower cluster—can be retained as a second productive stem. All other suckers should be removed weekly throughout the growing season.
- Big Beef: produces large slicing tomatoes on vigorous vines requiring consistent pruning
- Big Boy: heirloom favorite growing 7-10 feet tall with abundant sucker development
- Early Girl: fast-maturing variety that benefits from maintaining 1-2 main stems
- Juliet: cherry tomato type with prolific branching that responds well to pruning
- Most heirloom varieties: typically indeterminate with aggressive suckering patterns
Benefits and Drawbacks of Sucker Removal
Research across multiple university extension programs identifies several proven benefits to sucker removal on appropriate varieties. Pruned plants typically produce larger individual fruits since energy isn’t divided among as many growing points. Agricultural trials show that fruit size can increase by 15-25% when plants maintain 1-2 main stems versus unrestricted branching.
Improved air circulation represents another significant advantage. Dense, unpruned tomato plants trap humidity within their canopy, creating ideal conditions for fungal diseases like early blight and septoria leaf spot. Removing suckers opens up the plant structure, allowing air to flow freely and leaves to dry faster after rain or morning dew.
Earlier harvest timing often results from pruning. When plants focus energy on fewer fruits, those tomatoes mature 5-10 days sooner than on heavily branched plants. This matters most in regions with short growing seasons where early frost threatens late-season production.
The drawbacks deserve consideration too. Removing suckers reduces total fruit yield—you’ll harvest fewer tomatoes overall even though individual fruits grow larger. This tradeoff works well if you prefer big slicing tomatoes but doesn’t suit gardeners wanting maximum production for preserving.
Pruning creates wounds that can serve as entry points for diseases, especially if done during wet weather or with contaminated tools. Each cut represents a potential infection site. This risk increases when removing large, woody suckers that create substantial wounds.
- Benefit: Larger fruit size—studies show 15-25% increase in average tomato weight
- Benefit: Earlier maturity—fruits ripen 5-10 days sooner on pruned plants
- Benefit: Better disease resistance—improved airflow reduces fungal infection rates
- Benefit: Easier harvest and maintenance—pruned plants are more manageable to stake and pick
- Drawback: Reduced total yield—fewer stems mean fewer tomatoes overall
- Drawback: Disease entry points—each pruning wound risks infection if conditions are wet
- Drawback: Increased sun scald risk—fewer leaves mean less fruit protection from intense sun
Decision Framework: Choose aggressive pruning if you want fewer, larger tomatoes for fresh eating and have a long growing season. Keep more suckers if you’re maximizing production for canning, live in a short-season area, or grow cherry tomato varieties where size doesn’t matter.
Conclusion
The evidence is clear: what are tomato suckers and whether to remove them depends entirely on your tomato variety and harvest goals. For indeterminate types, strategic pruning redirects plant energy toward larger, earlier fruits while improving air circulation and disease resistance. Determinate varieties need minimal intervention—just remove suckers below the first flower cluster and let the plant follow its genetic programming.
Current horticultural guidance emphasizes making informed decisions based on variety type rather than following blanket pruning advice. Start by identifying whether your tomatoes are determinate or indeterminate, then apply appropriate techniques. Remove suckers when they’re small, work with dry plants, and don’t be afraid to experiment to find what works best in your specific growing conditions. FruitGarden continues to synthesize the latest research and practical growing insights to help you achieve healthier plants and more abundant harvests.
Frequently Asked Questions
How do you tell the difference between a sucker and a main stem on tomatoes?
The main stem grows vertically from the root system and has the thickest diameter. Suckers emerge from the 45-degree angle junction between a leaf branch and the main stem. If you trace a shoot downward and it connects directly to the soil, it’s the main stem. Suckers always branch off from a junction point higher up the plant.
Can you root tomato suckers to grow new plants?
Yes, tomato suckers root easily when placed in water or moist soil. Remove a sucker that’s at least 4-6 inches long, strip off the lower leaves, and place it in water. Roots typically develop within 7-10 days. Once roots are 1-2 inches long, transplant to soil. This works best with suckers removed in early to mid-season.
Should you remove suckers from cherry tomato plants?
Most cherry tomato varieties are indeterminate and produce abundant suckers. You can prune them following the same guidelines as other indeterminate types, but many gardeners leave more suckers on cherry tomatoes since fruit size isn’t a concern. The extra branches increase total yield without significantly reducing individual fruit size.
What happens if you don’t remove tomato suckers?
Plants develop into bushy, multi-stemmed forms with more but smaller fruits. This isn’t inherently bad—it’s actually the plant’s natural growth pattern. Unpruned plants produce higher total yields but individual tomatoes mature smaller and later. Dense foliage may increase disease pressure from poor air circulation, especially in humid climates.
When should you stop removing suckers from tomato plants?
Stop removing suckers about 4-6 weeks before your area’s expected first frost date. At this point, allowing new growth helps protect existing fruits from sun scald while they ripen. The plant won’t have time to develop new fruits from late-season suckers anyway, so there’s no benefit to continued pruning.
Do you need to remove suckers from determinate tomatoes?
No, don’t remove suckers above the first flower cluster on determinate varieties. These plants have a genetically predetermined number of fruiting stems. Removing suckers eliminates potential fruit-bearing branches and directly reduces your harvest. Only prune suckers below the lowest flower cluster to improve basal airflow and reduce disease risk.
Is it better to pinch or cut tomato suckers?
Pinch small suckers (under 2-3 inches) with your fingers for quickest healing and lowest disease risk. Use clean pruning shears for larger suckers that have developed woody tissue. Always work with dry plants and disinfect tools between plants. The pinching method creates smaller wounds that seal faster, reducing pathogen entry points.
