How far apart to plant tomatoes: Why tomato spacing is important

There are four main reasons to aim for well-spaced tomato plants:

  • Disease prevention. Tomato plants are susceptible to many diseases and if spaced too closely, insufficient air circulation can elevate the risk of disease.
  • Adequate light.  Heat-loving tomato plants need plenty of sunlight for healthy growth. If you crowd seedlings, the plants will cast shade on their neighbours as they grow.
  • Production. I like to use up all my growing space leaving little open soil for weeds to grow. Spacing tomatoes too far apart means that you’re leaving space for weed growth, losing valuable growing space, and reducing your overall potential harvest.
  • Less competition. As noted above, air flow is decreased when plants are crowded, but it also means they’re competing for water and nutrients.

Types of tomatoes

Determinate – Determinate tomato plants are also called ‘bush tomatoes’ and form compact plants that grow about three feet tall, although some larger varieties can grow up to four feet. Because the fruits of determinate tomatoes ripen around the same time, they’re often grown by gardeners who like to can or preserve their harvest. Determinate tomatoes are often left unsupported, but they can also be held upright with sturdy tomato cages.

Indeterminate – Unlike determinate tomato plants which grow to a certain size and stop, indeterminate varieties can grow six to eight feet tall. They only stop growing when the end-of-season frost finally kills the plants. Also called ‘vining tomatoes’, they yield their harvest over a long period of time and are best grown on sturdy supports like tall wire cages, stakes, or trellises. 

Best spacing for tomato plants

How far apart to plant tomatoes is dependent on the types of tomatoes grown – determinate or indeterminate – and the types of supports used. Trellised plants in sturdy cages or supports can tolerate a closer planting than those allowed to sprawl on the ground. Of course, there are other benefits to trellising your tomato plants. They’ll be less likely to suffer soil-borne diseases. 

Determinate tomatoes – Space dwarf determinate tomatoes, which only grow 12 to 18 inches tall one to two feet apart. Full-sized determinate tomatoes should be planted two feet apart. 

Indeterminate tomatoes – This is where supporting your plants makes a big difference with spacing. I plant staked indeterminate tomato plants 18 to 24 inches apart. They are pruned regularly during the growing season to control growth and encourage good air circulation. And while I don’t allow any of my tomato plants to sprawl on the ground, if you prefer to leave your indeterminate plants unstaked, space them three to four feet apart. 

How far apart to space the rows?

When growing in gardens or raised beds, leave four feet between rows to permit good air flow and, in the case of in-ground gardens, to give you space to work around the plants. 

Keep on top of pruning

Now that you’ve got your tomatoes properly spaced, don’t neglect pruning! Determinate tomatoes don’t need to be pruned, but staked indeterminate tomatoes need regular pinching to remove suckers which promotes healthy, productive plants. It’s not difficult to prune tomato plants, but it should be done every 7 to 10 days. 

Suckers are vegetative shoots that develop in the crotch between the main stem and a branch. Suckers do produce flowers and fruits and while leaving suckers can mean more tomatoes, the overall fruit size will be decreased. And of course, the plants become a tangle of foliage with little airflow. 

In early summer, I let two to three suckers develop, but pinch the rest every week or so. When the suckers are 2 to 3 inches long they’re easy to remove with your fingers. If you let them grow larger, you may need a pair of pruners to cleanly remove suckers. 

Learning how far apart to plant tomatoes isn’t difficult, and it’s so important for the health and production of your plants. For further reading on growing tomatoes, be sure to check out the award-winning book, Epic Tomatoes by Craig LeHoullier.

For more on growing tomatoes, check out these related posts: 

  • Tomato growing secrets for high yields and healthy plants
  • How to grow tomatoes from seed
  • 5 tips for growing tomatoes in raised beds
  • 4 ways to overwinter tomatoes
  • Should you grow grafted tomatoes?
  • Companion plants for tomatoes

Have you been wondering how far apart to plant tomatoes? Any tips to add?