Tomato Suckers: What They Are & Whether to Remove Them

Tomato suckers are the small shoots that grow in the V-shaped junction between the main stem and branches of indeterminate tomato plants. Removing them directs the plant's energy toward fruit production rather than excess foliage, but the practice depends on your tomato variety and gardening goals.

Understanding tomato suckers and proper pruning techniques can transform your garden yield. These seemingly insignificant shoots actually determine whether your plants focus energy on abundant fruit or excessive foliage. For indeterminate varieties—which continue growing throughout the season—strategic sucker management typically results in larger, higher-quality tomatoes with reduced disease risk. Determinate varieties, however, generally shouldn't have suckers removed as they form a bush-like structure with a predetermined fruit set.

What Exactly Are Tomato Suckers?

Tomato suckers emerge from the axillary buds located where leaf stems meet the main plant stem. These shoots would naturally develop into full secondary branches if left unchecked. While they contribute to overall plant size, they also divert valuable energy from fruit production. Recognizing them early—when they're 2-4 inches long—makes removal easier and less stressful for the plant.

Determinate vs. Indeterminate Varieties: Critical Differences

Understanding your tomato variety is essential before deciding whether to remove suckers. This distinction affects everything from pruning strategy to expected harvest timing.

Characteristic	Determinate Tomatoes	Indeterminate Tomatoes
Growth Habit	Bush-like, stops growing at 3-4 feet	Vining, continues growing until frost
Sucker Management	Generally not recommended	Essential for optimal production
Fruit Production	Concentrated harvest over 2-3 weeks	Continuous production throughout season
Common Examples	Roma, Celebrity, Marglobe	Beefsteak, Cherry, heirloom varieties

According to research from University of Minnesota Extension, determinate varieties form a flower cluster at the terminal growing point, naturally limiting their height. Indeterminate varieties continue producing new leaves and flowers indefinitely, making sucker management crucial for directing energy toward fruit rather than excessive vine growth.

When to Remove Tomato Suckers: Timing Matters

The optimal time for removing tomato suckers follows a clear seasonal progression:

1. Early Season (Transplanting to First Flowers): Remove all suckers below the first flower cluster to establish a strong main stem
2. Mid-Season (Fruit Set Period): Maintain 1-3 main stems by selectively removing new suckers weekly
3. Late Season (6-8 Weeks Before Frost): Stop removing suckers to maximize remaining fruit production

Research from Oregon State University Extension demonstrates that removing suckers when they're 2-4 inches long minimizes plant stress while preventing excessive energy diversion. Waiting until suckers grow larger creates bigger wounds that invite disease and requires more plant energy to heal.

Proper Sucker Removal Technique

The method you use to prune tomato suckers significantly impacts plant recovery and disease prevention:

• Pinching Method: Ideal for young suckers under 3 inches. Use thumb and forefinger to gently bend the sucker back and forth until it snaps cleanly. This creates a small wound that heals quickly.
• Pruning Shears Method: Necessary for larger suckers. Make a clean 45-degree cut about ¼ inch from the main stem. Always disinfect shears between plants with a 10% bleach solution.
• Timing Tip: Perform pruning in the morning when plants are turgid (full of water), reducing stress and promoting faster healing.

Situation-Specific Guidance: When Not to Remove Suckers

While tomato sucker removal benefits most indeterminate varieties, certain conditions warrant keeping some suckers:

• Container Gardening: Limited root space means plants need more foliage to support fruit production
• Hot, Sunny Climates: Additional foliage provides essential shade to prevent sunscald on ripening fruit
• Short Growing Seasons: Preserving some suckers can increase total yield before first frost
• Disease Prevention Strategy: When dealing with soil-borne diseases, allowing one sucker to develop below the first fruit cluster creates a new main stem if the original becomes infected

The Penn State Extension notes that in high-temperature environments (above 90°F/32°C), maintaining additional foliage can reduce heat stress and prevent fruit quality issues. Their field trials showed a 15-20% reduction in sunscald when plants retained strategic foliage cover.

Common Mistakes to Avoid

Even experienced gardeners make these tomato pruning errors that reduce yield and increase disease risk:

• Over-pruning: Removing too many leaves reduces photosynthesis capacity, resulting in smaller fruit
• Pruning during wet conditions: Increases disease transmission through open wounds
• Leaving stubs: Incomplete removal creates entry points for pathogens
• Using dull tools: Crushes rather than cuts stems, creating larger wounds
• Removing all suckers on indeterminates: Creates a single-stem plant vulnerable to breakage under fruit weight

Measurable Benefits of Proper Sucker Management

When implemented correctly, strategic tomato sucker removal delivers tangible improvements:

• 25-30% larger individual fruit due to concentrated energy allocation
• Earlier ripening by 5-7 days for the first harvest
• Reduced disease incidence by improving air circulation through the plant canopy
• Stronger plant structure supporting heavier fruit loads
• Higher quality fruit with better color development and sugar content

A three-year study by University of Wisconsin-Madison demonstrated that properly pruned indeterminate tomatoes showed a 40% reduction in early blight incidence compared to unpruned controls, while maintaining comparable total yields with significantly improved fruit quality.

Practical Implementation Guide

Follow this weekly routine for optimal tomato sucker management:

1. Inspect plants every 7-10 days during peak growing season
2. Identify new suckers (2-4 inch length is ideal removal size)
3. Disinfect pruning tools with 10% bleach solution or 70% isopropyl alcohol
4. Remove selected suckers using appropriate technique
5. Monitor plant response for signs of stress or disease
6. Adjust strategy based on plant health, weather conditions, and growth patterns

Remember that tomato sucker identification and removal isn't a one-size-fits-all approach. Your specific climate, soil conditions, and variety characteristics should guide your pruning decisions. The goal isn't complete sucker elimination but strategic management that optimizes your particular growing conditions.

Should I remove all suckers from my tomato plants?

No, not all suckers should be removed. For indeterminate varieties, maintain 1-3 main stems by selectively removing suckers. Determinate varieties generally shouldn't have suckers removed as they form a predetermined bush structure. Complete removal of all suckers creates vulnerable single-stem plants prone to breakage.

What happens if I don't remove tomato suckers?

If you don't remove suckers on indeterminate varieties, plants will produce more foliage but smaller fruit with delayed ripening. The dense canopy reduces air circulation, increasing disease risk like blight and mildew. While total yield might be similar, fruit quality and size typically decrease without strategic pruning.

Can removing too many suckers harm my tomato plants?

Yes, over-pruning can significantly harm plants. Removing too many leaves reduces photosynthesis capacity, resulting in smaller fruit and sunscald. Plants become more vulnerable to temperature stress and nutrient deficiencies. Research shows that maintaining at least 50% of original foliage is crucial for optimal fruit development and plant health.

When is the best time to remove tomato suckers?

The best time to remove suckers is when they're 2-4 inches long, preferably in the morning when plants are well-hydrated. Early season, remove all suckers below the first flower cluster. During peak fruit set, maintain 1-3 main stems with weekly sucker removal. Stop pruning 6-8 weeks before expected first frost to maximize remaining fruit production.

Do cherry tomato plants need sucker removal?

Most cherry tomatoes are indeterminate varieties that benefit from strategic sucker removal. However, because they produce numerous small fruits, you can maintain 2-4 main stems rather than the single stem often used for larger varieties. This balances adequate fruit production with manageable plant size and disease prevention.