How to Prune Tomato Plants for Bigger Harvests

Of course, you don’t have to prune your tomato plants. Millions of gardeners never prune their tomatoes and still get fruit. If life gets in the way, give them support, water, and love, and you’ll get tomatoes. But if you’re ready to advance your tomato game, it’s time to learn when and how to remove tomato suckers, lower branches, and overcrowded leaves—without hurting your plants.

Why Prune Tomato Plants?

What did those tomato plants ever do to us? Why attack them with sharp tools? Pruning tomato plants means removing lower branches, excess foliage, and fast-growing side shoots called suckers. This simple step offers several important benefits:

1. Reduce Disease Risk:
   Many tomato diseases on leaves thrive in damp, shady areas inside an overly bushy plant. Their enemy is good airflow and sunlight.  Pruning opens the plant so breezes can reach the middle and underneath, helping dry the foliage after watering or rain and minimizing fungal infections.
2. Prevent Soil-Borne Infections:
   Removing lower branches near or touching the soil stops rain or irrigation from splashing soil pathogens onto leaves, lowering the chance of infections starting there.
3. Increase Yields:
   Pruning helps the plant focus its energy on growing bigger, healthier tomatoes instead of producing extra leaves or fruit that won’t mature in time.
4. Encourage Earlier and Abundant Fruit:
   By cutting back competing branches and foliage, the plant can focus its nutrients. Instead of wasting effort on extra leaves or fruit that won’t mature in time, the plant can put more energy into growing bigger, healthier tomatoes on its main stems.
5. Make Garden Management Easier:
   Especially with indeterminate tomatoes, pruning keeps plants from becoming unruly, shading neighbors, or hiding fruit, pests, and disease symptoms.

When To Prune Tomatoes

The answer for when depends on the why. 

• Prune damaged or diseased leaves as soon as you see them.  I take regular garden walks with clean snips, from a few weeks after planting until late summer.
• Pruning for shape and to remove suckers begins once summer is in full swing and the tomatoes start growing vigorously. When you notice little shoots popping up in the crook between the main stem and a side branch, it’s time to prune.

Tools For Pruning Tomatoes

Tomato stems are soft, not woody, so you probably already have what you need: something to cut with and something to sanitize.

• Cutting tools: I use small, sharp snips like those for cutting flowers, but a sharp knife works, too. If you use pruning shears, choose the bypass type, not the anvil kind (which crushes instead of slices). The important thing is that your tools are sharp, clean, and in good working condition, so you get a clean cut and not a ragged tear.

• Sanitizing tools: Sanitizing is a must. Virtually every garden region has some sort of tomato disease lurking, even if you haven’t identified it yet. Cleaning your tools between plants helps prevent spreading infections, especially since pruning often targets diseased leaves. I’ve been tempted to skip this step, but it’s just too important.

Tip: I keep a small tube next to the garden with isopropyl alcohol(70%), Lysol, or a 10% bleach solution. You can also use Lysol spray or a 10% bleach solution (1 part bleach to 9 parts water, soak the tool for several minutes). I find the alcohol to be faster to use, and it doesn’t make my tools rusty like the chlorine in bleach can. 

How to Prune Tomato Plants

Unlike pruning fruit trees or grapes, tomatoes don’t need much artistry when pruning. It’s about as easy as spotting a sucker or a low branch and giving it a snip. There are two types of tomatoes—growing determinate or indeterminate varieties—with different pruning methods. 

How to Prune Determinate Tomatoes

Determinate tomatoes are more compact and bushy, growing to a genetically fixed size—and produce most of their fruit in a 2- to 3-week flush. My Roma tomatoes are determinate. They hit their peak in mid-summer.

Prune mainly to remove lower branches and leaves that touch soil. Avoid cutting growing tips where fruit sets.

1. Start pruning lower leaves as soon as the plant is established. 

2. Support plants with cages or stakes. 

3. After the first flower cluster appears, remove leaves and stems below it. Your tomato should now have a pretty bare stem for the first foot or so above the ground.

4. Continue light pruning to maintain airflow without exposing fruit to too much sun, which can cause sunscald.

How to Prune Indeterminate Tomatoes

Indeterminate tomatoes grow like vines. If you don’t pinch out the growing tip, they’ll just keep going—up, sideways, and around the garden. In a greenhouse, they can reach the ceiling! Indeterminate varieties don’t produce a big flush of fruit all at once, but rather a steady trickle until fall frost. Prune to remove suckers and maintain a manageable shape.

• Suckers are small shoots growing in the V between branch and stem. Removing suckers prevents the plant from becoming an unmanageable tangle that wastes energy.
• Pinch small suckers off with fingers or cut larger ones near the base with sanitized snips. Leave the lowest sucker just below the first fruit cluster.
• Remove any lower branches or leaves touching the soil or close to it. I like to be able to see underneath the plant by midseason. This not only improves airflow but also makes it easier to spot problems. Most tomato diseases will also appear near the ground first, so removing any infected foliage will also raise the foliage height off the ground. 

Check out this diagram from the University of Wisconsin Extension, which explains where to prune for sucker removal.

Tips For Successful Pruning (and Mistakes to Avoid)

• Start early: Don’t wait until you have a tomato thicket taller than you. Keeping up with the job takes only a couple of minutes every few days and will prevent your plants from getting out of control.
• Make it convenient: Keep snips and sanitizer near the garden in a small tub with a lid, right next to your garden (or in it). You’ll be more likely to nip off suckers and other problem stems if you don’t have to go back to the house and hunt up your tools.
• Snap gently: Small tomato branches can be snapped off instead of cut. A clean snap separates the branch at a natural point, but if it won’t come off easily, use your tool to avoid tearing.
• Sanitize between plants every time. Don’t skip this step. As discussed above, this prevents spreading diseases from one tomato plant to another.
• Mind your fingers: I’ve been holding other foliage out of the way and caught the webbing between my thumb and index finger with the tip of the snips. You’d be amazed how much that hurts.
• Prune in the morning: This allows the cuts to dry faster before the high humidity and cooler temperatures of the evening.
• Don’t stress if you snipped an extra branch. Tomatoes grow fast. Unless you cut off the main stem, it will recover.

What to Do With Tomato Prunings

Healthy prunings—like small suckers or leaves without disease—can go directly into your compost pile. You can also root healthy suckers in soil or water to grow new plants. However, if you prune diseased or blighted foliage, dispose of it in the trash or burn it. Never compost diseased tomato material, as pathogens can survive and infect future plants.