Anyone who has been gardening for longer than a season can tell you that growing tomatoes is equal parts frustration and reward. Gardeners love to grow them, but they can be downright diva-like.
It can feel like everything has to be just so for them to do well. But then you get those seasons where everything is right; you’ll find yourself picking pound after pound of fat, juicy tomatoes all summer long. And it’s pretty hard to beat the taste of an heirloom tomato that you grew yourself.
But sometimes, even when you know you’ve got the basics covered, there’s something off. It’s something you can’t quite put your finger on that’s keeping your plants from producing well. So, I’ve rounded up a few of the most common silent tomato problems.
It’s easy to spot what’s wrong when, “Oh my gosh, my tomatoes are dying!”
But it’s beyond frustrating when you’re staring at an otherwise healthy plant that’s not setting a lot of tomatoes.
So, let’s address three issues that often fly under the radar. If you check these off your troubleshooting list, chances are you’ll be on your way to that bumper crop of ‘maters.
1. Low Pollination Rates
What if you’re standing in your garden, looking at tomato plants loaded with tomato blossoms, but you’re just not getting any fruit?
The most likely cause is that your blossoms aren’t being pollinated.
This is a pretty easy fix that’s a two-step process. First, start hand-pollinating your tomato flowers. It takes a few minutes to work your way from plant to plant, but it’s the best solution to get tomatoes while you address the real problem – a lack of pollinators.
If you aren’t planting flowers in your vegetable garden, you’re doing yourself a disservice.
I’ve already made the case for all the smart reasons to grow flowers in your vegetable garden. But attracting pollinators is the best reason. The more flowering plants you have, the more pollinators will visit your garden, and low pollination will be a thing of the past.
Sure, we’ve all been told that marigolds and tomatoes go great together, and they do, but there are so many other great flowers you can plant in your vegetable garden that will help get your plants pollinated.
Borage attracts bees, and you can use it as a chop-and-drop fertilizer. Nasturtiums are another great choice, as they bloom profusely, early and all season long. Even chamomile makes a great pollinator attractant.
Make planting flowers in with your veggies a yearly habit, and you’ll increase the yield of all your vegetables, not just your tomatoes.
2. Improper Pruning
If you’re growing indeterminate tomato varieties, you’re going to need to prune them. And not just once per season. To encourage them to grow in a way that suits the support you’ve chosen, you’ll have to stay on top of their growth by pruning every few weeks.
However, how you prune can play a big role in fruit production.
For instance, I prefer to train my tomatoes to grow a main stem up a string. I prune off any new side growth. Doing this makes the plant much tidier, but it also means I’m forgoing the extra tomatoes that would have come from side stem growth. But because I’m growing my tomatoes vertically, they take up less garden space. I can plant my tomatoes a lot closer to each other, fitting more tomato plants in a smaller area. In the end, I still end up with a bumper crop of tomatoes.
If you’re growing tomatoes, so there are multiple leaders, then you need to prune in a way that gets air and sunlight into the heart of the plant while also ensuring the plant doesn’t get too tall for its support structure.
Too often, we’re advised to pinch off suckers. But this practice leads to fewer tomatoes. Learn how to prune indeterminate tomatoes the right way and why tomato “suckers” is a misleading name. Once you know how to prune tomatoes, you’ll actually be encouraging new blossoms on your plants.
Pruning or Topping Determinate Tomatoes
This is one mistake most gardeners only make once. Determinate or ‘bush variety’ tomatoes are bred to grow to a specific height. When the plant reaches maturity, it sets all of its fruit at once. After this main harvest is finished, you’ll likely get a few straggling tomatoes, but the plant will begin to shut down and die off.
If you top young determinate tomatoes (I’m not a fan of tomato topping) or prune them as they grow, you’re effectively diminishing the overall yield for that plant. Because of their compact nature, determinate tomatoes aren’t meant to be pruned.
3. Extreme Heat
Tomatoes are well known for being a sun and heat-loving crop. But it often surprises gardeners to find out that tomatoes shut down if the mercury climbs too high.
Oh sure, they’ll survive and come out the other side of an especially long heat wave, but until the weather breaks, you’re looking at a stalled tomato plant.
Tomatoes produce best when temperatures range in the mid-60s to upper 70s.
Once you get long periods where the days are hotter than 80 degrees, the plant conserves its energy. It no longer produces the right chemicals to trigger fruit set, and fruit that’s already on the vine will stop ripening.
When the heatwave finally breaks, your tomatoes will begin to put out blossoms again and ripen the fruit on the vine. Unfortunately, this is one problem where there isn’t a whole lot you can do but wait.
With each passing summer setting new record temperature highs, it begs the question – how do we grow tomatoes now? Quite a few of us are learning to shift our tomato growing season to a new normal to enjoy our favorite homegrown veggie. (Yes, I know, it’s not really a vegetable, but you know what I mean.)
Here’s the Number One Least Likely Issue
Fertilizer.
I can’t count the number of articles there are about fertilizing tomatoes to get big yields. It frustrates me to no end. Want big tomatoes? Fertilize them! Not getting enough tomatoes? Fertilize them! Want tomatoes sooner, later, last Thursday? Fertilize them!
Fertilizer is a great panacea in the gardening world, and it needs to stop.
Reaching for fertilizer, be it organic or synthetic, at the first sign that something is off is probably the worst thing we can do, and yet it’s such a common practice.
We fertilize indiscriminately without having a single clue if our soil even needs it. What’s worse, as home gardeners, we’re guilty of over-fertilizing when we use it. We either fertilize too often or add too much. It’s a waste of time and money and can lead to fertilizer runoff, burned roots and a nutrient imbalance in our soil.
Unless you’ve had your soil tested and you know it is deficient in certain nutrients, please put the fertilizer down and look elsewhere first. This is especially important if you already fertilized at the beginning of the season.
Most of us add organic matter like compost, mulch or leaf mold to our gardens every year. These all break down and replenish nutrients in our gardens. Generally, your soil has plenty of nutrients to grow the vegetables you want to grow.
You wouldn’t go to the doctor and say, “I feel pretty good, but I could be doing better, so please prescribe me some antibiotics.”
Please don’t misunderstand my point. I’m not against fertilizing.
Adding nutrients to the soil is incredibly important. But to do it in a manner that benefits the plants you’re growing, first, you have to know if there are deficiencies or imbalances. And that means testing your soil.
An Exception
If you’re growing tomatoes in a container, then yes, fertilizer could be an issue. This includes small, fixed bottom raised beds. Nutrients get depleted faster when container-growing, both because the amount of soil is much smaller and because they get washed out through the drainage hole of the container.
If you’re growing tomatoes in pots, then, yes, you’ll need to fertilize more often throughout the season.
Nope, No Pests & Plant Diseases Here
You might be surprised that certain pests or tomato-specific diseases aren’t a part of this list. Pests and plant diseases are acute causes for your tomatoes not to flourish. Because they’re pretty evident when present, it’s much easier to spot and treat the issue, so they don’t make the cut here.
But if you need help with those types of tomato-growing issues, you should check out the following:
20 Common Tomato Pests and How To Deal With Them
Tomato Blight: How to Spot, Treat & Prevent 3 Types of Blight
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