When it comes to maximizing tomato harvest, it is recommended to prune the tomato plants. However, people have some strong opinions about this when it comes to how to prune “correctly.”
Do you want to prune it on just one stem? Do you want to prune some of the suckers? Do you want to prune all the suction cups?
What I found in gardening for years is that general wisdom is not necessarily the right (or only) way to do things, and the way to pruning tomatoes has changed depending on where I live and what I expect from the plants.
This is what I’m doing now. And there are some tips on why (and how) to prune tomato plants.
First of all, what is a tomato sucker?
A suction cup is a small branch that appears from the “elbows” of a tomato vine. You can see the main stem (called the shaft) grows from the junction where the green branches meet at a 90-degree angle. The side chute, formed at a 45-degree angle, is a suction cup.
If left untreated, the sucker will eventually grow into branches that produce more leaves and fruit, resulting in a bushy tomato plant.
Most gardeners think that suckers are “bad” because they suck some of the plant’s energy, but they are a natural part of the growth of tomato plants. In my view, each sucker offers more fruit promises, but I can’t complain about it!
So the usual advice is to cut off all suckers when you see them, but is that really the best thing to do?
Whether to prune
First, if you’re doing a yard chore, you can remove this from the list. It is not necessary to remove the tomato sucker at all.
but! There are pros and cons to cutting them off, and you can resolve the argument by asking yourself one simple question:
Want a bigger tomato or more tomato?
Removing the suction cup means bigger tomatoes
Cutting the suction cups contributes to larger tomatoes. The fewer branches allow you to get less fruit overall, but the fruits that the plants produce are larger. This is because removing side shoots reduces competition for nutrients and concentrates plant energy on the production of larger fruits.
Pruning suckers also helps keep your plants healthy as they increase airflow around the leaves, reduce the risk of disease and limit the number of nesting sites for pests.
Maintaining the suction cup means more tomatoes
If you leave the suckers on the plants, those suckers turn into more grapes that produce more flowers, and you guessed it. Also, each grape needs more resources from the plant, so in most cases the fruit is smaller, but many of them and a longer fruiting period.
It is a toss-up between larger tomatoes or larger yields and the choices you choose, and neither method has serious consequences. It really depends on your gardening goals.
That being said, this is what I do in my garden now…
I leave suckers on tomato plants
I’ll back up for a while and confess that I’ve never pruned a tomato plant for years (while I lived in Southern California). I just didn’t think it was necessary. Being in Zone 10B gave me a very long growing season (often extending into winter) and I had so many sweet and juicy tomatoes that I didn’t care about their size (or if I lost some to pests).
But now I live in central Oregon. Here, the last frost is in June. If you’re lucky, you can extend the growing season in September before your garden gets hit by frost again. Since the tomato plants need to produce fruit before they freeze, they cannot waste energy on excessive leaf production. However, in my case, pruning all the suckers doesn’t help.
I don’t want to cut out all the suckers of the plants. Because I feel like I’m hedging all my bets on just a few tomatoes that I really hope to grow bigger. What if they are not ripe in time? What happens if the illness clears them? What happens if the hornworm destroys my tomato crop?
I don’t want them to ride too much on the large fruits I have selected. I want to continue supplying small fruits throughout the season, but if some of them aren’t perfect, it’s fine as more comes.
So, based on my goals, the best way for me is to keep the sucker.
But I don’t keep all of them. I still prune the plants, but do it selectively to ensure both a healthy plant and a stable supply of tomatoes.
How to prune tomatoes for a productive harvest
If you have a definitive tomato variety (also known as patio or bush tomato), stop here. There is no need to prune the plants.
The decisive tomato grows to a given height and produces all the fruits at once. Removing suckers from a surefire plant will ruin the harvest rather than help it.
However, if you are growing uncertain tomato varieties, pruning not only promotes the health of the plant, but also makes the plant too uncontrollable. Tomato plants are soft perennials that continue to produce stems and leaves (instead of flowers and fruits) until frost approaches the end. Selective pruning allows you to tell the plant what you want more or less, and refocus its energy.
Step 1: Prunes into one or two main stems.
Most tomato plants develop on what is called a “leader,” or on the main stem where all other growth appears. Sometimes there may be two stems. There are also multiple stems that branch out at the base.
Depending on how you step on, the first pruning task in a few weeks of planting is to choose one or two main stems to become a provider. This makes it easier to guide plant growth and make pruning more manageable.
Here’s how I decide:
If you are using a large tomato cage or Florida woven trellis for support and/or planting early in the season, keep two leaders. If you are using tomato ladders or string nets and/or planting them later in the season, prune them on only one leader.
If the plant has several major stems, choose the largest stem (or two) and remove the other stems with a clean puller.
It continues to block new stems that have sprouted at the base throughout the growing season.
Step 2: Remove stems and leaves that are touching the ground.
Stems and leaves sitting in the soil are susceptible to pests and diseases, so it is recommended to remove drooping leaves to reduce soil-borne diseases and improve air circulation.
Step 3: Pruning stem under the first flower cruster.
Once the first flower appears, prune all stems and leaves under its cluster. This tells the plant that it wants to spend more energy to produce more flowers and reduce energy by growing more leaves.
Leaf is essential for photosynthesis, but simply maintain the minimum amount of leaves needed to support the plant. All leaves require nutrients and water, and plants want to spend their resources on flowers and fruits rather than on external leaves.
Step 4: Pruning unproduced grapes.
Every 2-3 weeks, prune the bottom grapes (up to one third of the plant’s leaves) that do not have flowers.
This is where my methods go against what you could have been said. Instead of pruning suckers, I prune non-producing grapes so that the plants can concentrate their energy on the growth, growth and maturation of other grapes. Therefore, if the bottom branches do not produce flowers or fruits, I will cut them out.
This means removing the branches right next to the sucker, but since there are flowers, it leaves the sucker.
While you are in it, you must also remove dead, discolored or damaged leaves (especially the lower branches) and discard them into trash (as they may be signs of disease, not compost piles). Damaged leaves no longer support the plant, so you need to go.
Step 5: Finish the plants before the first frost.
Pruning the top of the tomato plant, blocking the tip of the main stem just above the top flower, two to three weeks before the first frost. Pick flowers and unripe green fruits that are not yet at their mature size.
Related: Find the first frost date with my interactive brockup tool
Topping with tomato plants will make you taller and unable to produce more leaves, as you remove flowers and unripe fruits near the end of the season, redirecting the plant’s energy and ripening the already produced fruit. (This is one of the tricks I recommend aging your tomatoes faster on the vine.)
Is it too pruned?
As beneficial as pruning, maintaining the health of your tomato plant, be keen on pruners and don’t start hacking grapes. In areas with long, hot and sunny days, there is actually less pruning, so cover the leaves over tomatoes.
Over-ups of tomato plants can also weaken them as they support their growth and provide energy for fruit production because they have fewer leaves. And weakened tomato plants lead to heat stress and compromised vitality, making them more vulnerable to pests and diseases.
In some cases, heavy pruning can even lead to catfaces (rough, deformed, or scarred fruits) as it is thought to reduce the amount of auxin (growth regulators) in the plant.
Find sweet spots where tomatoes can thrive with just the right amount of leaves while giving them a rich harvest, and remember that there are no rules for gardening, especially when it comes to pruning.
