An article by Travis Key from Lazy Dog Farm
Tomatoes are by far the most popular vegetable grown in backyard gardens across the country. The flavor of a homegrown tomato is significantly better than what you can find in a chain grocery store. However, tomatoes are not the easiest vegetable to grow. They can be susceptible to a wide variety of plant diseases, and they can also be quite hungry when it comes to nutrient demand.
Beginner gardeners often get mesmerized by photos of beautiful heirloom tomatoes in a seed catalog. And while these colorful, uniquely shaped tomato varieties are no doubt visually appealing, they might not be well-suited for your growing area or growing needs. Below we’ll discuss the major differences between indeterminate and determinate tomato varieties so you can make informed decisions about what to grow in your backyard garden.
Continual vs. “Burst” Tomato Production
Indeterminate tomato varieties have an “indeterminate” growth habit, meaning they’ll continue to grow and produce tomatoes when outside temperatures are favorable. These plants don’t make a huge number of tomatoes at one time but provide a “slow drip” of consistent production. Most of the varieties you’ll find in a big box store or on an online seed site are indeterminate.
Determinate tomato varieties produce a significant number of tomatoes in a short amount of time, and then they’re done. They don’t continually produce throughout the growing season like indeterminate varieties. These varieties can be harder to find and are mostly grown by commercial growers who need to maximize yields in a short time window.
One might think that the choice is a no-brainer given the continual production from the indeterminate tomatoes, but they’re not “indeterminate” everywhere. Tomato plants don’t like outside temperatures above 90 degrees. When the summer heat becomes brutal in the southern states, tomato plants will succumb to disease and insect pressure. This usually happens around mid-July here in south GA.
As a result, gardeners in the southern states don’t get much “bang for their buck” when growing indeterminate tomatoes. These varieties are better suited for areas with milder summers where they’ll continue to grow and produce until they’re killed by the frost in fall. You can get a couple months of production from indeterminate tomato varieties in warmer states, but nothing like the production you can get from determinate tomatoes.
As mentioned above, determinate tomato varieties produce more fruits in a shorter window. This is ideal for areas where the summer heat is going to kill all the tomato plants come mid-July. And it’s especially important if you’re planning on canning tomatoes or tomato sauces. With determinate tomato varieties, you can get all the production you need in a short time span.
While they’re perfect for the southern states, determinate tomatoes can also be useful in the northern states. Determinate tomato varieties can be succession planted to ensure a bounty of tomato production throughout the season. Instead of picking just a few tomatoes each week, you can pick buckets of tomatoes each week. The only downside is that you’d need to plan accordingly for succession planting.
Tomato Trellising Needs
Because they keep growing until heat or frost kills them, indeterminate tomato plants can get very tall. This means that you’ll need a substantial trellising system to support the plants and heavy fruits they produce. These plants will quickly outgrow tomato cages and other shorter trellising options. It’s not unusual for our indeterminate tomato plants to get 7-8’ tall before they’re done in mid-July. In areas with mild summers, they can grow 10-15 tall!
Determinate tomato varieties usually only get 4-5’ tall, so they don’t need a very tall trellis. Sturdy cages usually work well for these varieties if the cages are pushed far into the ground. Because determinate tomatoes make so many fruits at one time, the plants can get very heavy. As a result, they need a short and sturdy trellis. We prefer to use the Florida weave method with t-posts and string wrapped around the plants.
Tomato Pruning Needs
Indeterminate tomato varieties will benefit from pruning. Removing the “suckers” from indeterminate tomato plants as they grow will help the plant devote more energy to fruit production. Many gardeners prefer to frequently prune their indeterminate tomato plants to one or two main leading stems. This keeps the plants much more manageable for trellising. If you don’t prune indeterminate tomato plants, you’ll quickly have a massive, unruly plant.
Determinate tomato varieties don’t need to be pruned, and they’ll produce significantly more tomatoes if you don’t prune them. These plants are designed to be short and bushy so they can support the loads of fruits that they’ll produce in a small window. When growing determinate tomatoes, you want to maximize foliage to protect the large clusters of fruits from sun damage.
What Tomatoes Are Best for You?
Now that we’ve explained the major differences between determinate and indeterminate tomato varieties, how do you choose what’s best for you? You may want to grow both like we do, but you may want what’s best suited for your area or production demands. Indeterminate tomatoes can be frustrating for southern gardeners but are very rewarding for northern gardeners. We prefer the ‘burst’ production that we get from determinate tomato plants. But some gardeners just want a few tomatoes a week and the slow, continual production of indeterminate varieties is perfect for that.
Thousands of gardeners have been tuning in to The Lazy Dog Farm YouTube channel where Travis covers a variety topics ranging from how to successfully start seedlings to how to make a flavorful hotsauce that packs a punch. Accompanied by his wife Brooklyn and their two boys, the gardens on their 2 acre homestead in southwest Georgia are always filled with a wide variety of vegetables that are enjoyed fresh or preserved for later.