Growing tomatoes in your garden can almost seem like more of an art than science. While most tomato plants are fairly hardy, they need optimal growing conditions to flourish and produce an abundance of fruit.
Providing your tomatoes with enough space in your garden is an important aspect of plant growth and fruit yield. Depending on the type of tomato you plant, some will need a bit more space to spread out compared to others. It will also depend on how you plan to grow them, as tomatoes can be trained to grow in a certain direction.
Follow along here to learn how best to space out your tomatoes and why providing ample space is so important to their, and ultimately your, success.
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Determinate vs. Indeterminate
First, the variety of tomatoes you plan to grow matters greatly when planning out your garden. Determinate plants tend to be bushier with a short harvest window whereas indeterminate plants grow vertically as high as you’ll guide them and will continue to grow and set fruit until a hard frost.
That said, the way you intend to support your plants should be considered when planning out your space.
Supporting Determinate Varieties
As mentioned above, determinate tomato varieties tend to grow more like a bush, producing all its fruit simultaneously, within a 2-3 week period. They stop growing once their “season” is complete, only growing to be about 3-4’ tall. For this reason, many growers use tall cages to support them.
Caging is the most common way to support determinate tomato plants because they do not get very tall. Cages are easy to install, fairly inexpensive, and can be reused year after year. Some additional staking can be used if you live in a particular windy region.
Alternatively, you can pound t-posts, wooden stakes, or tall bamboo sticks between every two plants or so and use the Florida weave method. This is a common method among commercial tomato growers and those of us growing tomatoes outdoors. It can also be used successfully with peppers, eggplants, and some flower varieties.
The Florida weave method is likely the most commonly used and, in my opinion, the best option. The Florida weave can be performed as often as needed and provides very dependable support. With some practice, it can be a quick and fun process.
Pro tip: Cut a 2-3 ft long piece of PVC pipe that is 1.5 inches in diameter. Tie a pencil to the string you’ll be using and slip it through the PVC pipe. Now tie the end of your string to your stake and use the PVC pipe to easily weave through your tomato plants. The sturdiness of the pipe allows you to move quickly and efficiently.
Supporting Indeterminate Varieties
If you are growing tomatoes outdoors, the Florida weave will work best. Just be sure to buy 10 ft t-posts so you can take advantage of their height. Remember, they’ll only be about 8 feet tall once you pound them into the ground.
Due to the quick growth and tall heights that indeterminate varieties can reach, a trellis system will work best with them. If you are growing tomatoes in a greenhouse and have overhead support, you can use a trellis system.
This requires a trellis system including a mechanism to hang string down from and plastic clips to clip around your tomato plant as they grow. The key here is to keep the string nice and tight, so the tomato plant remains straight.
Furthermore, if you learn to “lower and lean” your tomato plants as they grow vertically, you can extend your season even further.
The Importance of Proper Spacing
While you may be able to fit more plants in your garden plot if you plant them close together, when you provide them with ample space, ultimately they will be better-performing and healthier plants.
Healthy plants result in more fruit, so it is worth spacing them out. Here are a few specific reasons why your tomato plants need proper spacing.
Spacing Limits Disease Pressure
Tomatoes can be very susceptible to fungal diseases such as Early blight, Late blight, Septoria leaf spot, and Powdery mildew so you want to keep the possibility of disease jumping from one plant to another to a minimum. This includes diseases that may live in the soil or that are transferred through wind and rain.
When tomato plants are planted too closely together, this risk increases, especially if foliage from different plants is able to touch.
When disease does appear, you might find yourself in a bad situation if you have planted them too closely together. Sometimes the only option at this point is cutting diseased plants out, which is always unfortunate.
Pro tip: Select cultivars bred for high disease resistance packages to keep risk at a minimum.
Spacing Provides Ample Airflow
All plants need to breathe, just like we humans so providing them with ample space is very important. Without enough airflow, plants cannot properly photosynthesize or convert food into energy, which could result in a pretty lackluster season. Airflow is especially important in particularly humid times of the year or in humid growing regions.
Similarly to airflow to the plant above ground, every plant needs to be able to breathe above ground as well. This is why you often will see that it’s recommended to have fertile, well-draining soil.
This can be accomplished by adding high-quality compost, broad forking, and ensuring your soil is high in organic matter. If you see lots of worms, your soil is probably pretty healthy and it’s a sign that circulation is good!
Remember, if plant roots cannot breathe and reach water, they will fail and ultimately your plant will die.
Pro tip: If you are growing in a greenhouse and can hang high-powered fans, it will drastically help with the airflow. Ideally, you should have one at each end of the tunnel on opposite sides, blowing in opposite directions so the airflow is circular.
Spacing Provides Ample Nutrients and Water
Tomato plants are known as heavy feeders as they need lots of nitrogen, phosphorus, and potassium to grow healthily and provide you with abundance all season long.
They are also in the ground for a long time so they must be fertilized several times throughout the season at key times of growth.
Spacing of Determinate vs. Indeterminate Plants
While there is no hard and fast rule for how to space out tomatoes for success, there are some general practices all growers should follow.
Determinate
If you choose to cage your tomato plants, they will likely need at least 3-4 feet simply for the cage itself. You could also try staggering your plants in a 4-ft wide bed, allowing you to make the most of your space, especially if it is limited.
If you stake your tomatoes or use the Florida weave, you can probably get away with 2.5-3 ft spacing.
The variety of tomatoes matters here, so take into account the size of the mature fruit. If you are growing paste tomatoes for canning, they shouldn’t need much more than 3-4 feet as the tomatoes are on the smaller side.
However, plants need more sun and nutrients to produce larger fruits. Something like a sauce tomato or a beefsteak will likely appreciate a little more “legroom”.
Indeterminate
Whichever way you choose to support indeterminate tomato plants, you want to give them 12-24 inches and this is dependent upon the variety and your support system.
We have experimented with one foot spacing on a trellis system and learned quickly that while it worked just fine for small cherry tomatoes, something like an heirloom or a beefsteak tomato requires more space, at least 18 inches but most of the time, two feet worked best, and gave us optimal performance.
Just remember, the closer your plants are, the more you need to keep on top of pruning, to keep the air moving between plants.
Keep in mind that with all tomato types and varieties, you want to leave enough space between plants for pollinators to fly comfortably and for you to harvest!
Grafted Tomatoes
2022 was our first year trying our hands at grafting our own tomato plants. We started all of the same varieties that we had grown in years past and then grafted them onto a rootstock.
When it came time to transplant, we experimented with different space options because we weren’t sure what to expect.
What we learned quickly is that not only do grafted plants offer you higher-yielding and healthier plants, the increased amount and size of the foliage is astounding!
That said, if you do start your own or buy in grafted plants, I recommend giving them all, no matter what type or variety, no less than two feet of space.
Don’t Forget to Prune!
Whatever spacing you choose to experiment with this season, you’ll want to make time for pruning your tomatoes at least once a week. This is crucial because you want to be sure that foliage from each plant stays in its own space. This will help keep diseases from spreading, airflow at a healthy level and allow the plant to focus on fruit production.
You should do a weekly walk of your tomato plant patch and check for sagging lower leaves, suckers of all sizes, and leaves above empty clusters, as they are no longer needed at that point. You should also remove any leaves that are touching those of another plant.
Note: Determinate plants don’t tend to need much pruning since they produce all of their fruit at the same time and then they are done for the season, but if a plant seems particularly cramped or the foliage is very dense, it probably wouldn’t be a bad idea to grab some shears and snip off a few leaves here and there. This is especially true if there are any yellowing or brown leaves.
Final Thoughts
There are many key reasons you want to space out tomato plants properly. Optimal performance, high yields, and low risk of disease are just a few of these reasons. Learning how to space out your tomato plants is not, by any means, difficult.
It takes a little bit of research, some patience, and experimentation to figure out what works best in your space. Once you figure out what type of tomatoes you are growing and how you’ll support them, give them at least 18 inches of space to grow, feed them well and enjoy the fruits of your labor!
