I am someone who looks forward to fresh, homegrown tomatoes every summer.
There’s nothing quite like biting into a perfectly ripened, backyard beauty. (That’s what I call homegrown tomatoes.) They’re so juicy and delicious. In my opinion, they are so much more flavorful than those you get at the grocery store. Plus, you are able to experience a wider range of tomato varieties if you grow them yourself, versus what you can find in most conventional stores and markets.
There are literally thousands of different varieties of tomatoes, but most of them can be classified as either determinate or indeterminate. The terms are often listed on the plant’s marker when purchasing plants or on the seed packet if growing tomato plants from seeds.
The words determinate or indeterminate are words used to classify tomato plants by their size, growth habits, and length and time of harvest. These characteristics are where you can recognize the key differences between the two.
Essentially, the ways to tell the difference between determinate and indeterminate tomatoes is duration and form of growth, along with their size. Generally speaking, determinate tomato plants are smaller, and have a shorter growing season, and indeterminate tomatoes are larger and have a much longer growing season. The differences ultimately lie in the length and time of harvest, and the size of the plants.
Though the majority of tomato plants are indeterminate, there are currently more determinate varieties to choose from than ever before.
In this article, I outline the key differences between indeterminate and determinate tomatoes, and how to identify them when inspecting mature plants. Plus, I provide a quick guide for choosing which to grow in your own backyard. So, let’s dig in!
Size of the Plants
One of the key differences between determinate and indeterminate tomatoes is the size of the plants.
Determinate tomato plants are often grown in cages, containers, or even without support, as they have a smaller, more compact shape. While the expected height of determinate tomato plants vary depending on the exact variety, they can be expected to grow anywhere from 2 – 4 feet tall. Due to their smaller, more petite size, determinate plants rarely require staking. (Though they may need stakes once they are heavy with ripening fruit.) Often, determinate tomatoes are marketed as “bush,” “patio,” or “container” plants, due to their compact size, and because they can grow very well in smaller spaces and pots. (But, you can grow them in your garden too.)
Not only are the plants smaller than indeterminate, but determinate tomato plants often produce smaller tomatoes, too.
Indeterminate tomato plants have much longer stem growth and can reach staggering heights. Remarkably, it’s not uncommon to hear of plants growing to be 12 – 15 feet tall. Though, on average indeterminates tend be 6 – 8 feet tall.
You can help control indeterminate tomato plants size by pruning them, and they can even be consolidated down to just a couple of stems. Due to their ample size and lengthy branches, indeterminate tomatoes are best suited for growing in a large garden plot where they have plenty of space. A tomato plant that’s not labeled as a “patio,” “bush,” or “container” is likely indeterminate.
Indeterminate tomato plants have numerous long, pliable branches that require staking to keep them upright, and to keep their fruit off of the ground. They’re commonly referred to as “vining plants,” though they aren’t actual vines. These branches can be trained to grow on a vertical support such as an a-frame or lean-to style trellis.
Determinate and indeterminate tomato plants differ in their growing habits.
Determinate tomato plants will flower nearly all at once, and they will stop producing shoots once flowers form at the terminal end of the branch. This signals the stem to stop growing.
Indeterminate plants, however, will form flowers along the sides of the shoots, and will have buds, flowers, and flowers that have been pollinated all on their branches at the same time. Indeterminate tomato varieties have a much longer growth period and will produce flowers and fruit until colder weather and frost arrives. On the contrary, determinate tomatoes will stop growing once all of their flowers have finished forming. The indeterminate tomatoes will continue their cycle of forming new buds, flowers, and fruit all season long.
Fruit production is another key difference between determinate and indeterminate tomatoes.
Determinate tomato plants produce fruit early in the season, usually within a two – to three-week period, with all of the fruit tending to ripen all around the same time. Then, the plant yellows and is finished producing fruit for the season.
Indeterminate varieties, however, will produce fruit all along the stems and throughout the growing season, but they will ripen much slower and only one at a time.
It is important to note that in addition to determinate and indeterminate, there are some semi-determinate varieties.
In terms of size, semi-determinate varieties may grow slightly taller than 2 – 4 feet, but they will still keep their compact form and fall between the two main varieties in growth habit.
Other characteristics to examine
Unfortunately, you can’t tell the difference between determinate and indeterminate by looking at the seeds or seedlings, so you will have to wait until the plants are more mature to distinguish between the two.
A considerable clue as to whether the plant is determinate or indeterminate is whether it has long branches or is more “bush-like.” The plant that has longer branches, with sparse foliage, is likely to be indeterminate and the bushier plant is more likely to be determinate.
The formation of new leaves at branch areas is a characteristic of both types of plants, so that won’t help you in distinguishing the two. But, a way that you can tell them apart is to check for suckers at the base of your tomato plant and at the crotch of a leaved stem. These are small growths that will not flower and they are characteristic of only indeterminate plants. These suckers draw energy that would be better used for developing and producing fruit, and removing them is advised to help prevent problems with mildew and with fruit ripening.
Should you go with determinate and indeterminate tomatoes for your home garden?
There are multiple different factors to consider when choosing between growing determinate and indeterminate tomatoes.
Three of these are the length of the growing season where you live, the size of the space you where you’d like to grow them, and the ways you are hoping to use your harvest.
Determinate tomatoes are a more favorable choice if you are planning to grow tomatoes in a pot or small space, have a shorter season, or would like them to ripen all at once. (Something that is favorable for canning or cooking.)
If a determinate plant is best suited for you, but you’re hoping to have a longer harvest times, consider buying multiple different varieties that have varying maturity dates, or try stagger your plantings. That way, you won’t be limited to only having the single harvest that doesn’t span the entire growing season.
Some determinates that have proven to do well in backyard vegetable garden are: Celebrity, Small Fry and Oregon Spring.
If you have a larger space, and you’re interested in having fruit throughout the growing season, indeterminate varieties may be better suited for you. But it is important to bear in mind that indeterminate varieties can be much slower to ripen, and require support.
If you’ve determined that an indeterminate tomato variety is more appealing to you, and you have a shorter growing season, be sure to plant them as early in the season as possible so they have plenty of time to mature and ripen.
Some common indeterminate types that have proven to do well in a home garden setting are: Brandywine, Early Girl, Mr. Stripey, Beefsteak, Red Cherry, Sweet 100, and Cherokee Purple.
Determinate and indeterminate tomato plants are most distinguishable from one another based on size, growth habit, and length of growing season. Each variety is better suited for a different set of circumstances and will flourish in varying settings.
A great way to help you remember the difference between the two is that determinate have a “determined” number of ripened fruit, and growing season, while indeterminate have an “undetermined” size or growing length.
There are quite a few varieties to choose from when deciding which variety of tomatoes you’d like to grow. Depending on the space you have available, and the use you have in mind for your bounty, it is probably quite clear which of the two you’d be better off choosing to grow in your garden.