Gardener Scott advises when to top tomatoes for more fruit and better-shaped plants

If you're wondering when to top tomatoes, Gardener Scott has the answer. The Colorado-based master gardener recently explained just when you need to perform this essential aspect of tomato plant maintenance to get more fruit out of your plants. 

A lot of learning how to grow tomatoes is about timing, especially if you live in an area that gets cold winters. Don't be late with this step of tomato growing if you want to be harvesting ripe fruit soon. 

What is tomato topping?

Basically, topping tomatoes is pinching out their new growth, or 'removing the growing tips of these plants,' as Scott puts it. He explains that 'on an indeterminate tomato plant the growth is pretty consistent; at each of the nodes, the junctions with the main stem you'll see a leafing branch. Often you'll have a sucker that extends from the main stem.'

This is, in a nutshell, how tomatoes grow, and 'at the tip of the plant, this process continues: you have a main stem, a leaf branch, and a sucker.' 

You'll often hear advice to pinch off the sucker, but Scott says that 'the growing tip will keep on growing and growing.' However, 'if you pinch off this growing tip, there's nowhere else for the plant to grow.'

This is the most effective method for controlling tomato plant growth, which will easily get to over six feet, which 'makes it difficult to harvest'. Controlling tomato plant growth will also help it produce more fruit – but only if you start topping your plant at the right time.

When to top your tomatoes, according to Gardener Scott

And the right time to start topping? It's 'six to four weeks before the first frost date.' Why? Scott explains that 'while it's still warm, the plant is putting a lot of energy into just growing bigger. When we put stress on the plant, we're signaling something is happening, the plant is threatened and will now redirect this energy into the fruit.' 

If you top your plant in late summer, you'll get fruit earlier. Otherwise, 'many of us will have green tomatoes on the plant' right up to the first frost date, without being able to harvest anything. You can do this with the side of the plant as well as the top if it's growing this way. If your first frost date is coming up in October, you'd better start topping your tomatoes now! This applies to growing vegetables in pots as well as tomatoes in your beds.