Topping Tunnel Tomatoes

The signs of the inevitable season change are mounting. One of those signs - the topping of our tunnel tomatoes - came this past week. What is topping tomatoes? Why is it important and what is it’s purpose? We’ll go over the reason we top the tomatoes and the results we hope to see.

As a refresher, the tomatoes we grow in our tunnels are an “indeterminate” variety meaning that they will continue to grow until either the frost gets them or they succumb to disease. We’ve written about how we manage that growth in several blog posts over the course of the season.

So what is topping tomatoes? It’s basically exactly like it sounds: we cut the top of the main stem completely off so that no further vegetative growth is possible. Why would we do such a thing?!

A topped tomato plant. Notice the flowers (fruit truss) just below the cut stem.

We know that the first frost is approaching. Most years we see that happen in the first half of October and usually closer to the beginning of October than the middle. Because of that, we waste plant energy and vigor in trying to continue the vegetative growth. By topping the tomato plants, we force the plants to focus their remaining energy on growing out the last of the tomatoes for the season.

We’ve left enough tomato fruit trusses to allow about 4-5 weeks worth of tomatoes. We figure we will get about one truss worth of tomatoes per week per plant. It’s a little bit of a moving target as the daylight decreases day after day and the temperatures fluctuate more so this time of year. Both of these, have an impact on how fast tomatoes will ripen!

So while the signs of seasonal change mount we will still have about a month of tomatoes left. Summer isn’t quite over yet!