When we plant tomatoes, we hope for big, juicy red–or purple, yellow, orange, even green–tomatoes and large crops of healthy plants. Sunshine, fertile soil, proper watering, and mulching are all important for a bumper crop. But is there anything else you can do?

While pruning suckers is a common topic of discussion among gardeners, topping tomato plants is less common but can still be a tool for tomato growers. But not all tomatoes benefit from topping. 

Topping tomato plants involves pruning the growing tips, removing them to force the plant to do what we wish. Gardeners top their tomato plants to hasten fruit ripening in autumn and, more commonly, to stop the plants from getting any larger. If you have the space, growing huge indeterminate tomato plants is quite satisfying, but they can take over (mine often do). Topping can help you from losing your garden aisles to the tomato jungle.

Gardeners growing tomatoes on a trellis vertically also trim off the growing tips so the fruit isn’t hanging so far above their heads that they need a ladder to pick it. Topped tomatoes will cease growing taller and instead begin concentrating their energy on the fruits they’ve already set. Topping isn’t the same as pruning to remove suckers–it refers to only removing the top or final portion of the plant.

Understanding Types of Tomato Plants

All tomato plants are not the same. While they often look similar when purchased at the garden center or as seedlings, mature plants vary greatly in size and shape. Tomatoes are classified as determinate or indeterminate. Learning the quirks of each will greatly increase your success as a home tomato grower.

Only indeterminate tomatoes benefit from topping. If you top a determinate tomato, you’ll likely miss out on some of the potential yield. Knowing which type of tomato you’ve planted also helps with spacing and caging or staking needs. 

Here’s a quick refresher on the two types of tomato plants:

Determinate Tomatoes:

• Often called bush type.
• Don’t need as much staking or caging (although some support is still a good idea).
• Reach a specific size and set a terminal bud, then stop growing.
• Fruit harvesting occurs in a short time window, usually 2-3 weeks (all at once instead of a few at a time).
• Many paste tomatoes are determinate.
• Common determinate varieties include Siberian, Celebrity, Roma, and Early Boy Bush Hybrid. 

Indeterminate Tomatoes:

• Called vining or climbing tomatoes.
• Require vertical support.
• Can become huge plants and keep growing until the frost.
• Set and mature fruit from midsummer until the first frosts, with a continuous crop.
• Many cherry and beefsteak varieties are indeterminate.
• Popular indeterminate varieties include Big Beef, Sun Gold, Early Girl, Mortgage Lifter, and Red Brandywine.

If you aren’t sure which type of tomato you’re growing and still have the seed packet or the plastic label from the pot, it’s easy to look up online. For mystery tomatoes whose identity is uncertain, it can be tricky. Many heirloom or older tomato varieties are indeterminate, and quite a few hybrids are determinate, but it’s not a sure thing. While many paste tomatoes are determinate, some of our favorites, like the San Marzano, are indeterminate. Look at the plant’s flowering pattern and growth for clues.

• Determinate tomatoes eventually form a flower cluster at the terminal shoot and stop growing taller after that. 
• Indeterminate tomatoes set only lateral flower clusters and continue to grow taller (or sprawl more) all season. 

The Case for Topping Tomatoes

Topping tomatoes can be a good idea for indeterminate varieties.For those of us gardening in areas that receive a killing frost, our indeterminate tomatoes will keep setting fruit. However, as autumn approaches, many of those fruits won’t get a chance to ripen. The same idea can be applied to melons and squash, and many folks will remove those last-to-set fruits they know won’t have time to fully develop. 

Topping tomatoes removes the plant’s options. It can no longer keep setting fruit and growing larger, so what is it to do with all the energy it harvests from the sun? The only option left for the plant is to put that energy into making the existing fruit the best it can be. Topping forces the energy from the plant into the remaining fruit and can hasten ripening. 

Removing the growing tip by topping also limits the plant’s final size, which can be important for larger varieties. Greenhouse tomato growers will top plants when they reach the top of the trellis. Gardeners may top indeterminate varieties to keep tomato growing areas tidy and manageable and avoid the impenetrable tomato vine maze that often overgrows aisles and causes delightful but still problematic access issues late in the season.

Reasons to Skip Topping Tomatoes

Of course, you can grow tomatoes without topping them. Determinate varieties won’t need topping, and indeterminate varieties will be fine if left without a haircut. 

You may wish to allow your tomatoes to just keep growing along the trellis or cage. If your plants are not getting too big for their support structure, and your killing frost is not for some time, there isn’t any urgency to top the plants. Topping does have the potential to reduce the overall yield per plant, although keeping tomatoes under control can allow you to increase total production by planting closer together.

Topping tomato plants too vigorously can also result in sunscald, which happens when tomatoes are not properly shaded by leaves. Basically, they’re getting a sunburn. While a little sun helps things along, too much sun causes injury to the ripening fruits.

How to Top Indeterminate Tomatoes

The art of topping tomato plants is in the location of the cuts. Start by finding the last fruit set on the branch. Look for the cluster of fruit farthest from the roots which is far enough along to have time to ripen before frost. Since indeterminate tomatoes will keep flowering and setting fruit until frost, there may still be tiny new green tomatoes and blossoms above this point, but if they don’t have time to mature, they aren’t going to do any good. It seems counterintuitive, but snipping those off isn’t hurting your harvest.

Before snipping too many branches, look at which leaves or leaf clusters provide needed shade to the fruits below. Removing too many tops or too much of the tops may expose your existing fruit to sunscald. Allow a few leaves to remain on the plant above the last fruit set to provide a bit of shade.

To top your indeterminate tomato plants:

• Using snips or scissors, cleanly snip through the stem at the next node (leaf joint) above the fruit you identified as mentioned above. 
• If you have time remaining in your growing season, the tip cuttings, as well as any suckers you’ve pruned, can be rooted easily in water and potted up to make more tomato plants. 
• You may need to top tomatoes weekly until they settle in. Not every plant will reach the size you want at the same moment. When topping tomatoes in late summer to ripen fruit before frost, you can top them all at once, but remember to allow enough leaves to prevent sunscald.

Topping tomato plants is only beneficial for indeterminate varieties and isn’t necessary for good health or high production. However, it is a method to keep growth in check and to give a little boost to those last few tomatoes in the fall.