Tomato Plant Suckers

What a tomato sucker actually is

A tomato sucker is a new shoot that grows in the axil — the 45-degree angle where a branch meets the main stem. If left to grow, a sucker develops into a full secondary stem with its own leaves, flowers, and fruit.

Suckers appear on every indeterminate tomato plant. They’re a natural part of tomato growth — the plant’s way of branching. Left unchecked, a single tomato plant becomes a multi-stemmed bush. Whether you want that depends on your variety and goals.

How to identify a sucker vs. a leaf or branch

• A leaf: Grows directly from a single point on the stem; has no growing tip of its own
• A branch (lateral): Grows from a node; part of the planned structure for that variety
• A sucker: Grows specifically in the axil between the main stem and a branch. It develops its own growing tip and, if left, becomes another stem

Suckers start small — often 1/4 inch or less. At that size, they look like a tiny shoot in the crook of the stem. They grow fast in warm weather. A sucker that’s barely visible on Monday can be 3 inches long by Friday.

Indeterminate vs. determinate: the rule that changes everything

Whether you should remove suckers depends almost entirely on your tomato variety type.

Indeterminate varieties keep growing indefinitely until frost. They need support and benefit from suckering because the plants otherwise become enormous and unmanageable. Most popular heirloom varieties (Brandywine, Cherokee Purple, Mortgage Lifter) are indeterminate. Many hybrids are too. See indeterminate tomatoes for a full list of what counts.

Determinate varieties grow to a set size, produce a concentrated fruit set, then stop. Removing suckers on determinates reduces the number of fruiting stems without producing bigger individual fruit — it just lowers total yield. Big Boy, Celebrity, and Roma are determinate. Check the seed packet or tag.

When to remove suckers

The ideal time to remove a sucker is when it’s under 2 inches long. At this size:

• It snaps off cleanly with fingers
• The wound is tiny and closes quickly
• The plant loses minimal energy

For a weekly pruning schedule, remove suckers during your regular maintenance pass. In warm weather (Zone 6+, July), a sucker can grow from invisible to 3 inches in 4–7 days.

The 2-inch rule: Pinch off anything under 2 inches. For suckers 2–4 inches, cut with clean scissors or pruning shears rather than snapping. For suckers over 4–6 inches, decide: if they’re causing airflow problems, remove them. If they’re large and established, leave them — removing a 6-inch or larger sucker stresses the plant and leaves a wound large enough to be an entry point for disease.

How to remove suckers correctly

Method 1: Finger pinching (best for small suckers)

1. Hold the main stem steady with one hand
2. Grasp the sucker between thumb and forefinger
3. Bend it sharply to one side — it snaps off cleanly at the base
4. No tool needed; no wound treatment required

This works perfectly for suckers under 2 inches and is the fastest method during routine maintenance.

Method 2: Cut with clean scissors or pruners

For suckers 2–6 inches:

1. Use sterilized scissors or pruners (wipe blades with isopropyl alcohol between plants to prevent spreading disease)
2. Cut as close to the stem base as possible without cutting into the main stem
3. Remove the entire sucker, not just the tip — leaving a stub allows disease to enter

Method 3: Missouri pruning (hot-climate modification)

In hot US climates (Zones 7–10, and anywhere with intense summer sun), removing suckers entirely can expose tomato fruit to sunscald — a bleached patch on the fruit from direct UV exposure.

Missouri pruning keeps one small leaf from each sucker to shade nearby fruit. Instead of removing the entire sucker:

1. Pinch off the tip of the sucker
2. Leave the first or second leaf from the base of the sucker
3. This leaf shades the fruit cluster below without allowing the sucker to grow into a full stem

I use Missouri pruning in July and August in Zone 6b when sunscald risk peaks. In spring and fall when the sun angle is lower, full sucker removal is fine.

The 2-stem training system (most popular US approach)

Instead of keeping plants to 1 stem, many US gardeners allow one sucker to grow as a second main stem. This is the 2-stem system — a good balance between productivity and manageability.

How to set up a 2-stem plant:

1. When the plant is 12–18 inches tall, identify the first sucker below the first flower cluster
2. Allow this sucker to grow — it will become Stem 2
3. Remove all other suckers
4. Train both stems up separate strings, stakes, or trellis wires — see DIY tomato trellis for support options
5. Continue removing any new suckers that appear on both stems

The 2-stem system gives more fruit per plant than single-stem without the complexity of a sprawling multi-stem bush. It’s the default for most home gardens growing tomato plants on a trellis or string.

What NOT to remove

The main growing tip

The main growing tip is the terminal bud at the very top of the plant. It is not a sucker. Never remove it unless:

• You’re intentionally topping the plant at end of season to push energy into existing fruit
• The plant has grown above your trellis and you want to stop upward growth

Removing the main growing tip stops the plant from producing new fruit above that point. This is sometimes done 4–6 weeks before first frost to redirect energy into ripening existing tomatoes.

Flower clusters

Flower clusters are not suckers. They grow from the main stem at set intervals and produce your fruit. Never remove flower clusters unless they’re diseased.

Lower leaves with purpose

Leaves below the first fruit cluster are often removed for airflow purposes — a different practice from suckering. Leave lower leaves in place during early growth; begin removing them only after fruit set begins on the lowest cluster.

Does suckering improve yield?

The research is nuanced. University of Florida IFAS Extension trials on indeterminate tomatoes show:

• Pruned to 1 stem: fewer total tomatoes, but significantly larger individual fruit
• Pruned to 2 stems: moderate fruit count, good size
• Unpruned: most total tomatoes per season, but smallest individual fruit and much higher disease pressure

For US home gardeners who grow tomatoes for fresh eating, 1–2 stem plants often produce more satisfying results even if total weight is similar to unpruned plants. The fruit is larger, easier to harvest, and the plant is manageable enough to inspect regularly for pests.

For gardeners maximizing total production for canning or preserving, unpruned or 3-stem plants may produce more total weight — but the tradeoff is a dense, hard-to-manage plant that requires vigilance for disease.

Sucker propagation: free plants from suckers

Suckers you remove don’t have to go to the compost. Tomato suckers root easily and produce a genetically identical plant in about 2 weeks.

How to root a sucker:

1. Take a sucker cutting 4–8 inches long (longer cuttings have more surface area for root development)
2. Remove lower leaves, leaving 2–3 leaves at the top
3. Place in a glass of water on a bright windowsill — not direct sun, which wilts the cutting before it roots
4. Change the water every 2–3 days
5. Roots appear within 10–14 days
6. Transplant into potting soil once roots are 1 inch long

These plants can be transplanted outdoors in late summer for a fall crop in Zone 7 and warmer, or grown in containers indoors through winter for an extended harvest.

Managing suckers in containers

Container-grown tomatoes need more aggressive suckering than in-ground plants. In a container, root space is limited, and a multi-stem plant quickly outgrows the pot’s ability to support it.

Stick to 1-stem systems in containers. Remove all suckers promptly. See how to grow tomatoes in pots for spacing and container size recommendations — a pot too small is the main limiting factor for container tomatoes, and suckering helps compensate for limited root space.

Feed container tomatoes regularly — they rely entirely on you for nutrients. Tomato fertilizer covers the options for in-season feeding in both containers and ground beds.

Season-end topping

When you’re 4–6 weeks from your first expected frost, top indeterminate plants by cutting off the main growing tip. This stops new fruit production above that point and redirects energy into ripening existing tomatoes on the vine.

This is the one time you intentionally remove the main stem tip — it’s not suckering, but it uses the same timing mindset. Watch for blossom end rot at the end of season, which can increase when plants are stressed from topping combined with calcium fluctuations in soil.