July is over. Welcome to August! If you have a garden and are growing tomatoes, you might have some big bushy plants that are overcrowding your garden space. This is particularly true if you have cherry tomato plants in your gardens (they tend to get very big and very bushy). In our small gardens, I am here to grow produce, not leaves and branches. I can’t eat those! One way to increase your tomato production is by pruning tomatoes. In this episode, I am going to discuss how to prune tomatoes to improve the health of your plants and to grow more tomatoes. Buckle up, buttercup, because we are going to talk about aggressively pruning those plants!
Download (28.6 MB, 30 mins 55 secs)
How to Prune Tomatoes to Improve Production and Plant Health
Today’s podcast, post and YouTube videos are particularly timely. In the Small Scale Life Facebook Group, our friend and new gardener Alex has a great question:
“My tomatoes are so out of control and are completely shading my peppers. I have at least 10 peppers that have stopped growing and those are my favorite. Can I cut back the tomatoes? Can I attempt transplanting the peppers? At this rate the peppers are not going to grow so these are my only two options besides just pulling them.” – Alex from Illinois.
There is no need to pull the peppers! I think we can figure out a way to aggressively prune tomatoes and get more sunlight to those peppers.
Be advised: by aggressively pruning, you will get more tomatoes from your plants! I think you can handle it though.
Where to Begin?
The first thing you need to do is take a deep breath and prepare yourself mentally. Pruning might make you nervous if you never have done it before, but don’t worry. It’s like your giving the tomato plant a haircut; the plant will grow more fruit, branches and leaves.
Pruning will signal to the plant that it needs to produce more buds and thicken the stem. At the same time, all of those leaves and branches are taking energy from the plant, and removing them allows the plant to use that energy for tomato production.
Determinate vs. Indeterminate Tomatoes
Here are examples of Determinant vs. Indeterminate Tomato Plants. The Determinant plant (bush-type) is on the left and an Indeterminate plant (San Marzano) is on the right
Now that I have convinced you to prune your plants, we do need to talk about Determinant versus Indeterminate tomato plants.
Determinant tomato plants are your bush-type varieties. They are great in a container or in a small garden. You DO NOT want to prune these plants. The reason is that determinant tomato plants produce tomatoes all at once, at the same time. If you trim determinant plants, you might be sacrificing tomatoes. Who wants to lose tomatoes like that?
Indeterminate tomato plants produce fruit all season long (until the frost). These tend to be more vine-like, and you want to prune these plants. Pruning keeps the plant healthy and focuses all the energy into the fruit.
Remember: we do this gardening thing to grow produce, not to grow bushy plants (with small or no harvest). I can’t eat leaves!
Three Steps to Pruning
Break out the clippers; we’re going in!
What do you prune?
Productive tomato plants begin to sprout all kinds of branches off the main stem. There can be branches that hang low and touch the soil. There are other branches that sprout on top of other branches. Some of these plants can get out of control and crowd out other plants unless you prune them back.
Obviously you do not cut or break the main stem. Life is not over if you do, but please don’t cut or break the main stem (it has NEVER happened to me, ahem). You are looking for specific branches called suckers and side stems, and I am going to walk you though how I prune my tomato plants in three steps:
- Find and remove the suckers
- Remove the side stems
- Remove and leaves beyond the tomato flowers
Sounds easy, right? Well, let’s go into more detail on each step.
Step 1. Find and remove the suckers
Suckers are branches that grow in the “armpit” or “V” formed between the main stem and branch. Indeterminate tomato plants have them, and depending on the variety, you could have a project on your hands!
Cherry tomato varieties get big, and while they produce a lot of tomatoes, they also grow a lot of suckers. I have a high priority on pruning these plants, and as soon you get done removing the suckers, they suddenly have grown back!
Suckers take energy from the fruit and result in smaller tomatoes. I focus this step. Suckers keep coming back, so keep inspecting and pruning your indeterminate plant all season.
NOTE: You can remove older, more mature suckers and actually grow new tomato plants from them! I actually did that this year, and I will talk about that in a future post.
Step 2: Remove the side stems
Side stems are low hanging branches that come off the main stem and have leaves that droop onto the ground. These branches usually do not bear fruit and are conveyor belts for insects, fungus, disease and bacteria, especially when water splashes onto their leaves.
Ever notice how septoria leaf spot starts low on a tomato plant and works towards the growing tip? If you get blight on your tomato plants, there is a good chance the mold or virus infected your plants from the side stems.
Keeping side stems in check will allow the tomato to grow a strong, thick stem and focus energy into the fruit. Plus, keeping those leaves off the ground has some additional benefits:
- Allows you to inspect the tomato stems and tomatoes near the base of the plant
- Helps you water the plants by keeping the water low and slow
- Allows you fertilize or mulch without foliage getting in the way.
I aggressively prune tomatoes, especially the side stems. I remove the side stems from the base of the plant to the first fruit. This year, I even pruned the side stems a little higher than that!
I have not had blight issues that my brother and my mom have (and they use my seedlings). I truly think aggressively pruning the side stems is a reason I have escaped the blight issues common in gardens.
Like the suckers, side stems keep coming back, so make sure you keep your plants trimmed up!
Step 3: Remove and leaves beyond the tomato flowers
Sometimes you will find leaves growing beyond the tomato flowers. While you could leave these, I remove them. Why not have the plant concentrate its limited energy on the actually development of tomatoes?
Some folks call these leaves “suckers,” and maybe they are. These are not a huge priority for me, but if I see them, I will remove them. I want the best tomato I can grow in a small space!
Quick Guide to Prune Tomatoes
In case you want to have a reference video (for yourself or for family/friends – feel free to share), I developed a quick video for the Small Scale Life YouTube Channel that shows the three steps to prune tomatoes. You can watch it here:
Tools of the Trade: How Do I Prune Tomatoes?
How do you prune tomatoes?
That depends on what you are pruning of course!
For smaller suckers, simply pinch the sucker with your forefinger and your thumb close to the main stem. Carefully rock the sucker back and forth until it snaps. This works particularly well for the young suckers that are just emerging or are a few inches long.
Older, more mature suckers need more firepower (so to speak). Use a clippers or a knife to cut off the sucker at its base.
Again, I cannot stress this enough: be careful not to cut off the main stem when you are dealing with older, more mature suckers.
For those side stems and branches with yellowing leaves, use pruning tools (clippers or knife) as well. Also, you should disinfect the tool between plants, especially if the leaves are yellowing or have yellow and black spots. You REALLY do not want to transfer any disease to other plants.
I typically use clippers Julie got me for my birthday last year. I love these clippers, and I will have a link to them on the Small Scale Life Kit Store.
Putting It All Together
Pruned tomato plants growing in the sun and about to bear fruit – July 2018
I was trying an experiment this year: I was not aggressively pruning like I usually do. With my no pruning experiment, I was finding pants with a lot of foliage and not a lot of tomatoes. As you can see in the video, there are stretches on the Black Cherry and the San Marzano plants that have no tomatoes.
That isn’t what I expected, and upon seeing a lack of tomatoes, I went into Grim Reaper Pruning Mode. I followed my three steps and pruned pretty aggressively.
If you look at the video or pictures in this post, you can see how I trimmed these plants up. Don’t worry: the wounds from pruning healed fairly quickly.
What happened? I need to post a new video and Garden Update, but I noticed the tomatoes grew a few more inches, and the plants were starting more buds! One of my cherry tomatoes is now over seven feet tall!
Pruning works. Give it a try. Keep those plants trimmed up and sucker free, and I think you will be amazed by how productive your tomato plants will be. As my friend Adam Rapier from Colorado said in the Small Scale Life Facebook Group:
“I did that [pruned tomatoes] last year, and I had more tomatoes than I knew what to do with. This year, no pruning; not so good on production.”
Give it a try! See what happens next and let me know!
Gardening Gateway
If you want to know more about gardening, check out the Gardening Gateway page on Small Scale Life. There are a lot of resources about starting plants, blight and pests, vertical gardening and a host of other topics for you there.