What Are Suckers on Tomato Plants? How to Identify and Manage Them

By Sarah Chen · May 21, 2025

Suckers on tomato plants are side shoots that grow in the axil where a leaf meets the main stem. If left unchecked, they can reduce fruit yield by diverting energy from fruit production to excessive foliage. Proper identification and management are essential for healthy, productive tomato plants.

What Are Tomato Suckers and Why Do They Matter?

Tomato suckers are vigorous secondary stems that emerge from the crotch between the main vertical stem and a leaf branch. These shoots have the potential to develop into full-sized branches with their own flowers and fruit. However, allowing too many suckers to grow can lead to overcrowded plants, reduced air circulation, increased disease risk, and smaller yields.

Common Characteristics of Tomato Suckers

Grow at a 45-degree angle from the leaf axil
Resemble small stems with tiny leaves
Appear quickly during warm growing conditions
Can become indistinguishable from main stems if not removed early

Why Remove Tomato Suckers?

Pruning suckers helps direct the plant's energy toward fruit development rather than vegetative growth. This is especially important for indeterminate tomato varieties, which continue growing throughout the season.

Benefits of Sucker Removal

Increases fruit size and ripening speed
Improves airflow, reducing fungal diseases like blight
Makes harvesting easier due to less dense foliage
Supports stronger main stems when trained properly

Determinant vs. Indeterminate Tomatoes: A Key Difference

Understanding your tomato variety is crucial when deciding whether and how aggressively to remove suckers.

Variety Type	Growth Habit	Sucker Management	Fruiting Pattern	Recommended Pruning
Indeterminate	Vine-like, continuous growth up to 10+ ft	Regular sucker removal recommended	Produces fruit continuously	Single or double-stem pruning preferred
Determinate	Bushy, stops growing at 3–4 ft	Minimal or no pruning needed	Fruits all at once, short window	Avoid heavy pruning; reduces yield

Table data source:1, 2

The data shows that indeterminate tomatoes benefit significantly from sucker pruning due to their prolonged growth and fruiting cycle. In contrast, determinate varieties set all their fruit early, so removing suckers can actually reduce total yield. Misapplying pruning techniques based on variety type is a common gardening mistake.

How and When to Remove Tomato Suckers

The best time to remove suckers is when they are small—ideally 2–4 inches long. Larger suckers create bigger wounds and stress the plant more.

Step-by-Step Pruning Guide

Inspect plants weekly during peak growing season (late spring to summer)
Identify suckers at leaf axils
Pinch off small suckers with fingers (called "pinching out")
For larger suckers, use clean pruning shears to prevent disease spread
Prune in the morning on dry days to allow wounds to heal faster

Popular Pruning Methods

Single-Stem Pruning: Remove all suckers; ideal for tall cages or trellises
Double-Stem Pruning: Allow one strong sucker near the base to form a second main stem
Missouri Pruning: Tip-prune suckers instead of removing entirely, reducing shock while limiting growth

Common Mistakes in Sucker Management

Over-pruning determinate tomatoes, leading to reduced yields
Using dirty tools, which spreads pathogens like bacterial spot
Pruning during wet weather, increasing infection risk
Removing too much foliage at once, exposing fruit to sunscald
Confusing suckers with flower clusters, accidentally removing fruit-bearing branches

Frequently Asked Questions About Tomato Suckers

Do all tomato plants need suckers removed?

No. Indeterminate varieties benefit from sucker removal, but determinate types should generally not be pruned. Removing suckers from bush tomatoes can reduce overall yield since they naturally produce fruit on multiple branches.

Can I grow a new tomato plant from a sucker?

Yes. Healthy suckers 4–6 inches long can be rooted in water or soil to grow into new plants. This is an effective way to propagate heirloom varieties and extend your harvest.

When is the best time of day to prune tomato suckers?

Morning is ideal because the plant is turgid, wounds seal faster, and humidity drops through the day, reducing disease risk. Avoid pruning during midday heat or when leaves are wet.

Will leaving suckers kill my tomato plant?

No, but unmanaged suckers can lead to overcrowding, poor air circulation, and higher susceptibility to diseases like late blight. While not fatal, it can drastically reduce fruit quality and quantity.

Is it better to pinch or cut tomato suckers?

Pinch small suckers (under 3 inches) with your fingers to minimize damage. Use sterilized pruning shears for larger ones to make clean cuts and reduce infection risk. Always wash hands and tools before and after pruning.