Tomato University - Determinate vs. Indeterminate

Tomato U™ - Determinate vs. Indeterminate Tomatoes

In this article we'll talk about the differences between determinate and indeterminate tomatoes and if/how it affects your garden plans.

First and foremost, you should still select your tomatoes for their physical characteristics and your personal preference. Color, size, sweetness, disease resistance, time to maturity, etc. These are independent of their determination as the world's most delicious tomatoes are of both types. Whether a tomato is determinate or indeterminate describes the growth pattern of the tomato and the total harvesting period. Determinate is often abbreviated Det., and indeterminate Ind. or sometimes Indet.

Determinate

Determinate varieties, such as Washington Cherry, produce tomatoes all at once, and are a bush-type tomato that generally do not need staking or pruning. They often stay more compact, and are recognized because the stems terminate in a cluster of fruit. This stops the stem growth and the plant in finished once all the fruits have matured. All tomatoes on a determinate plant will mature around the same time, leaving maybe a 2-week period during which you can pick and eat the tomatoes. These varieties are sometimes chosen by canning enthusiasts because the entire process can be planned and executed at once and then the plant discarded, making room for more vegetables in the garden.

Indeterminate

Indeterminate tomatoes, such as Brandywine, Green Zebra, or Black Krim, produce fruit over the course of the season instead of all at once. They also tend to grow much larger and often require staking or trellising in order to support the weight or quantity of tomatoes they can produce. Because the plants can get so dense, pruning is recommended so that all the leaves can get sunlight and make more tomatoes. We discuss pruning and staking in a separate article. If the leaves are struggling to get sunlight, the plant will produce more leaves in order to find the sun. This results in your plant using all its energy to create leaves, and therefore less energy making sugar, thus fruit. Many cherry varieties and most heirloom varieties are indeterminate, though you simply need to check the description of your plant to make sure.

Garden Planning

Now that you know the difference between determinate and indeterminate tomatoes, you can plant your garden so that you have tomatoes all season long making the proper use of space.

Sometimes gardeners will plant a determinate variety next to an indeterminate one so that two indeterminate varieties don't get tangled up with each other.
Other times people will plant one or two indeterminate varieties where they have room for a trellis or stake, and plant determinate varieties in pots on the patio where a cleaner, more compact plant is desired.
Indeterminate varieties are great in Topsy Turvys™ because they can make long vines that produce hundreds of tomatoes without needing additional staking.
Determinate varieties can often be grown next to lettuces and carrots because they will provide shade for them while minimizing the risk of taking over the entire area or crushing the plants.