How to Prune Your Tomato Plants

There is really no right or wrong in pruning. If you don't prune at all, you will still have plenty of tomatoes.

If your plant is growing out of control, it's OK to cut it back. Don't prune so much that you put your plant in distress or make it think it is dying.

Determinate vs. Indeterminate

Determinate tomato plants (check the label or google your variety) grow like a bush. Prune off leaves that come into contact with the soil — this helps prevent diseases and pests from getting on your plants and improves air circulation around the base. Otherwise, not much pruning is needed.

Indeterminate plants (check the label or google your variety) grow tall with long vines. Same rule applies: prune off leaves touching the soil.

Vines and suckers are the same thing. Every vine, every sucker you prune would have potentially produced tomatoes. If you need to prune them, it's OK.

Topping Off Vines

Once the plant is too tall — reached the top of the cage — prune off some vines at the top or gently let them grow back down. If you excessively top off vines all at once, your plant may think it's dying and send the message to ripen all the green tomatoes immediately. Don't go crazy with your clippers.

Caution: sunscald. Pruning vines that are shading mature tomatoes may expose fruit to too much direct sun. Tomatoes do not need direct sunlight on them to ripen.

How Indeterminate Vines Grow

If you do little or nothing, many vines will grow. Every time a leaf appears, a vine usually grows from the crotch where that leaf meets the trunk. As your plant grows you'll have tons of vines. It's OK to thin them out or top them off at the top of the cage. Don't prune off your best, healthiest vines.

The vines you want to keep are the ones branching from the main trunk. Notice in the drawing how lower vines grow from the main stem and branch into 2. After that branch, prune off others that want to grow. As your plant grows, the main trunk will divide into 2 vines and each of those will branch into 2–3. Keep these; prune the rest.

Every plant is a little different. Play it by ear. Remember: if you do absolutely nothing, you are still going to get lots of tomatoes. There is no right or wrong unless you prune so much you kill the plant. That rarely happens. You could be the first. Hahahaha.

Step by Step: Getting More Involved

Want to try more deliberate pruning? Start with just 1 or 2 plants your first season.

Plant your indeterminate tomato — good varieties like Better Boy and Big Beef are capable of producing large amounts of beefsteak-size tomatoes. Plant at the same depth as in the container it came in from the store. When you use great potting soil, you do not need to plant deep.

As your plant grows, trim off leaves touching the soil. Let vines grow from the trunk to the outside of the cage. Each of these main vines can grow 4–6 feet and produce 6–10 big beefsteak tomatoes. As vines grow up the outside of the cage, zip tie them to prevent the weight of tomatoes collapsing them to the ground.

Once you have enough vines growing up the outside of the cage, prune off any new ones that want to grow. Every time a new leaf comes out, you get a new vine — pinch those off. Use bamboo sticks to train vines toward the outside of the cage, then zip tie them as they grow up.

Pruning off a sucker. Each time a leaf grows, a new vine/sucker grows from that spot. Thin these out.

When you look down from the top of your cage and it's hollow — all vines growing on the outside — you'll know you've done it right.

An Early Girl in a container. Without zip ties, all these vines would collapse to the ground from the weight of the tomatoes.

Always remember: there is really no right or wrong in pruning, and if you do no pruning at all, you will get plenty of tomatoes.

You're welcome to share this information with others — clubs, family, friends. Sharing tips helps us all be better growers.

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Related Guides

Master the fundamentals of growing →
Choosing the right container and cage →
Browse indeterminate and determinate varieties →

Dave Freed / 🍅 The Tomato Guy