One of the single most important tasks you can do to help your tomatoes stay healthy, strong and productive is to prune your plants throughout the growing season.
The list of reasons why gardener’s need to prune their tomato plants is lengthy. For starters, it can aid greatly in preventing disease and potential attacks from pests. Even more, pruning helps to improve air circulation within the plant, which can help to increase pollination and lead to higher yields.
Pruning also makes tomato plants tremendously easier to maintain. When a tomato plant’s lower limbs are pruned up, it makes it simple to water and fertilize because you can quickly get to the base of the plant. And perhaps best of all, weeds can’t hide either and are easy to get rid of!
Unfortunately, when it comes to when, where and what to prune on a tomato plant, there is often a lot of confusion. Do I only cut oversize branches? Should I be removing all of the suckers? Can I top my tomato plants if they get too large? What about branches that have tomatoes already on them?
With answers to all of those great questions and more, here is a look at when, how and what to prune from your tomato plants this year – and how to have your tomato plants healthy, strong and producing a bigger crop than ever!
The Simple Secrets To Pruning Tomato Plants
When it comes to pruning tomato plants, there are three critical areas that need to be addressed. The bottom of the plant, the mid-section, and of course, the top. Each of these three areas requires a bit of a different approach when pruning. Let’s start with the bottom and work our way to the top!
Pruning The Bottom Of Tomato Plants – Why Pruning Up Is Important!
When it comes to the level of importance, trimming up the bottom of your plants is by far the most critical pruning task of all. In fact, even if you are not going to prune any other part of your plant, always prune up the bottom!
Why? Because much of the rot, disease and pest issues that can affect tomato plants comes from the soil. For starters, soil borne diseases such as tomato blight, which happens to be one of the deadliest of all diseases for tomatoes, is caused from spores living in the dirt below.
These spores are easily transmitted to plants when they splash up on the lower leaves of plants. Especially when it rains or when plants are watered. From there the infection spreads right up the plant until it eventually kills it. See: How To Stop Tomato Blight!
Why Pruning Helps
By pruning the bottom branches off, you help to remove nearly all of the connection between the soil and the foliage above. Not only can it help with blight, but also it makes it harder for pests to climb up the plant.
Last but not least, by clearing out the bottom area, you allow circulation to work up into your plants. That can be key in drying out overly wet foliage that can cause mildew. But even more, that additional air flow can really help in pollinating the flowers on the plant.
How High To Prune – The Simple Secrets To Pruning Tomato Plants
How much to prune up from the bottom of your plant depends on the tomato variety. For shorter determinate types of tomatoes (Roma, San Marzano, etc.), we like to prune up ten to twelve inches under the plant. For larger indeterminate tomato varieties, we prune at least twelve to eighteen inches off the bottom of the plant.
Creating this open space makes it hard for crawling ground insects and pests to get an easy lift up to your plants. As an added benefit, it also gives you easy access to the root zones of your plants for watering and fertilizing.
Listen In Below To Our Podcast On Tomato Pruning!
Do the bottom pruning gradually as the plant grows through the season. Start by removing the first few branches early in the growing season. As the plant continues to grow and fill out, continue to prune up to get to the desired height of clearing for each variety.
Once space at the bottom is cleared out, always be sure to apply a thick layer of mulch and cover any soil. The mulch will help keep soil from splashing up high on plants. It also helps to prevent weeds and keeps the soil moisture and temperature regulated.
Use Clean, Sharp Pruners – The Simple Secrets To Pruning Tomato Plants
Before pruning, always be sure you are using a sharp pair of hand pruners or heavy-duty garden scissors. Dull blades will tear the plants, injuring them in the process. Also, make sure you wipe down your blades to disinfect them as you move to each plant. Affiliate Product Link: Premium Titanium Bypass Pruning Shears
Blight and other disease can be easily transferred from plant to plant by the blades. A basic sanitizing or chlorine wipe will do the trick. Finally, always try to prune early in the morning or later in the evening. Plants are at their highest stress level during the hot mid-day sun, and avoiding this time is better for the plants – and the gardener!
Pruning The Middle Sections Of Tomato Plants
When it comes to pruning the middle of your tomato plants, less is more. Start by always pruning back any “wild branches” that cross over into paths or other plants. Next, trim out a few middle branches to allow light and air into the mid-section of the plant.
We like to select branches with little to no flowers on them or weak, short branches. This allows the more productive branches to remain and ripen the existing fruit. Do not stress, overthink or over-prune at this point. Simply remove a few branches and stems to open up the plant.
Pruning The Tops Of Tomato Plants
So can you prune off the tops of overly large tomato plants? The answer is yes, and it is something we have done for years to keep our tomatoes and the supports they are on in check.
Usually by mid to late summer, many of our tomato plants begin to grow too tall for our supports. We simply top off the plants to keep them manageable. It allows the plant to direct its resources to ripening fruit, and not growing more foliage.
Topping also makes harvesting much easier, and prevents the splitting and cracking of branches that become too heavy to support. Again, make sure you use sharp pruners and simply cut the plant off at the highest point you would like it to remain.
What About Pruning Suckers – The Simple Secrets To Pruning Tomato Plants
So what about the suckers on tomato plants? Tomato suckers are small shoots that form in the “v” portion where a stem and the branch connect. These will produce blossoms or fruit, but many gardeners like to remove these because it is thought to take power from the plant.
Although these small shoots may use a tiny bit of energy, it is extremely minimal. Especially when you consider they do not produce blossoms or fruit. We used to remove them, but after a few years of side by side experimenting in our garden showed us it simply didn’t affect our crop yields or plant health, we now leave them be. It certainly is a time saver at the least!
Always Prune Away Disease & Damaged Branches – The Simple Secrets To Pruning Tomato Plants
Finally, when it comes to pruning, always stay on the lookout and remove any branches or leaves that may show signs of black spot or mold. This will help to keep anything from spreading rapidly on your plant.
When pruning suspicious or damaged leaves and stems, be sure to keep them out of your compost bin. The pathogens have to have high heat to die off, and most home compost bins don’t get hot enough to kill them. For a video look at pruning, check out our YouTube Channel here: How To Prune Tomatoes Video
Here is to pruning your tomato plants this year – and to growing a bumper crop of tomatoes! Happy gardening – Jim and Mary.
Jim and Mary Competti have been writing gardening, DIY and recipe articles and books for over 15 years from their 46 acre Ohio farm. The two are frequent speakers on all things gardening and love to travel in their spare time.
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