Since we are on the topic of pruning, we’d be remiss if we didn’t also talk about tomato pruning!
With tomatoes, we have indeterminate and determinate varieties. (There are also semi-indeterminate, which is basically a blend of the two.) Indeterminate varieties will grow more like a vine, putting out a main stem and also secondary stems. Determinate varieties grow more like a bush. It’s important to know what you’re growing as you treat them slightly differently through the season.
With indeterminate tomatoes, you’ll get what are called suckers. These suckers produce off the main stem, typically at a 45 degree angle, where a lateral branch with leaves is produced. These suckers, if left unchecked, will turn into a secondary main stem. The end result is a crazy, wild growing tomato that is difficult to manage, harvest and keep well trellised. In addition, removing the suckers allows the plant to focus on certain growth, which in our case is vertical to the top of our greenhouse.
Most gardeners prefer to remove those suckers, promoting a singular growing stem that can be trellised and more easily managed. We use a pair of fine tipped snips for this kind of pruning, it’s an essential tool for the northern cucumber and tomato grower!
These suckers will continue to produce throughout the season, so it’s not a “one and done” kind of thing. We usually revisit them about one a week or so, or just whenever we’re observing our plants. You’ll find as you do it, some suckers will seemingly “blow up” overnight sometimes, which is indicating that’s where the plant is focusing its growth.
With determinate tomatoes, there’s a whole lot less pruning that you need to do. Most gardeners want the “full bush” to grow out, so there’s no need to manage suckers. Determinate tomatoes will grow to a certain size and simply stop, focusing its efforts on growing and maturing fruit. You can trim off branches that are annoying or not looking so hot, should you decide.
For both types of tomatoes, we generally recommend removing the lower leaves and branches from the tomato plant. Once the plant is about 2-3 feet tall, you can safely remove lower branches. This promotes good air flow, which reduces potential for disease and soil borne problems from getting to your plant. Be sure to leave at least several branches so the plant can continue to photosynthesize. Our “end goal” is to remove all the branches up to the first flower cluster, which sometimes has to be done over a matter of a month or more.
We’ve gotten to the point, as avid tomato growers, where we focus on a singular type of tomato. We love indeterminates as they give us the ability to take full advantage of our vertical growing space, optimizing fruit production with a relatively small footprint. There’s logic in focusing on determinates, too, if that type of tomato works better for your growing situation. It can be challenging to focus on both, since you’ll get vastly different growing behaviors and will have to adapt to two different growing methods.
We do promote some very aggressive tomato pruning that helps promote fruit maturity, but that happens much later in the season. We’ll talk about this as we get closer to our first frosts. But, we’re still a long ways from that point and we’re trying not to think about it right now.
So, get out there and prune those tomatoes! We know this stuff may seem rudimentary to the experienced grower, but it’s important for us to hit all skill levels of growing!
