Determinate vs. Indeterminate Tomatoes
If one is willing to grow tomatoes in their own yard or in containers, and if they have heard about determinate and indeterminate tomatoes, they might wonder what these types are and how to differentiate between them and choose the right one among them.
Well, tomatoes fall into these two categories, i.e., determinate and indeterminate, which are decided by their growth habit. Each of them has its own characteristics from which one can identify which variety they are looking at. It’s also important to identify the category because which category one chooses will be determined by their space, usage, and growing season duration.
Published: August 6, 2022.
Determinate vs. Indeterminate Tomatoes – How to Differentiate?
One can be overwhelmed by the numerous varieties and options available in tomatoes. They may wonder which variety they should choose and on what basis. An easy answer to this question is first to consider the duration of the growing season of each variety.
Determinate tomato varieties have a short growing season, and so they ripen sooner (generally two weeks). (Moreover, once the first flush of fruit has ripened, the plant’s vigor is reduced, and production of fruit becomes little to none.)
Indeterminate tomato varieties, on the other hand, have a longer growing season and tend to bear fruits all through the summer, and sometimes even in fall and winter, until finally, cold weather or frost strikes and kills them.
Note: In proper conditions, indeterminate tomatoes can grow for more than one season - the reason why tomatoes are fruit and not vegetables :)
The next factor one should consider is what they’re going to do with their tomatoes. If they need a lot of tomatoes at once for canning or making sauce or juice, they should better choose a determinate type that ripens all at around the same time.
The growers that wish to have fruits all through the growing season, to add them daily to sandwiches or salads, should better choose an indeterminate tomato variety.
Most paste or Roma tomatoes are determinate varieties, for example, ‘Amish Paste’ and ‘San Marzano’. Some others have been bred to be determinate; hence the grower can harvest them all at one time in quantity. These include ‘Rutgers’, ‘Marglobe’ and ‘Celebrity’.
But the majority of tomato varieties are indeterminate, including most heirlooms and cherry types. Even many of the dwarf tomato varieties are indeterminate. Some of the most popularly grown tomato varieties like ‘Sungold’, ‘Brandywine’, ‘Sweet Million’, ‘Big Boy’, and ‘Beefsteak’ fall into the indeterminate category.
Early producing varieties, like ‘Early Girl’, also fall into the indeterminate category. However, they are often considered as semi-determinate because they normally mature earlier and die back before the end of the growing season.
One Cannot Differentiate from Seeds or Seedlings or Production of Leaves
One cannot tell if a tomato seed or seedling is of determinate or indeterminate type because both will look the same.
Once the plant grows and reaches maturity, only then can the difference be seen as a determinate tomato plant will be of compact size and bear blossoms or fruits at the ends of their branches, and an indeterminate plant will be a much bigger vine, bearing flowers or fruit all along its stem. To know which type the seed or seedling is, the buyer has to read the label.
Determinate type plants are often marketed or labeled as “container”, “patio” or “bush” plants. Or if they’re taking the seed or seedling from a friend, they have to ask the friend which type it is.
Although indeterminate tomato seeds or seedlings in a nursery may sometimes be labeled as IND or INDET or Indeterminate, they may not always be labeled as being indeterminate, and thus a buyer may be confused regarding what they are buying. But it’s generally observed that any tomato seed packet or seedling that is not labeled as a bush, container or patio variety is likely to be indeterminate.
However, if one doesn’t want to depend on such guesswork, they should look up the particular variety before buying, so they know exactly what they’re getting.
Even the production of new leaves on branches doesn’t help in distinguishing between the two types because it’s the same in both types of plants.
Form of the Plant
While distinguishing between determinate and indeterminate tomatoes, the form their plant takes is a big hint towards which variety they’re growing, as one of them grows as a vine, whereas the other is a bush.
The determinate tomato variety often grows in a cage or even with no support since its shape is more compact (therefore, they’re also called “bush” tomatoes).
They are typically smaller than indeterminate plants. Most of them grow up to a height of 4 to 5 feet. Hence, they typically don’t need to be pruned or get their suckers removed since they stop growing after attaining a compact size and shape. In fact, pruning is not recommended for determinate plants since any limbs cut down will reduce the amount of fruit.
So, these plants are ideal for beginners or those who don’t have much time for maintenance. Also, these plants produce most of their fruits on the terminal end of the branches.
Although determinate tomato plants have a compact shape and size, sometimes they still may need staking or caging because once they produce fruit which then plumps up and ripens, the plant has to carry a quite heavy load, and the branches have to hold considerable weight.
In such a condition, staking helps the plant, especially to withstand heavy winds and rains.
On the other hand, the indeterminate tomato plants have their stems grown much longer, which keep growing until the arrival of cold weather. Hence, they are called “vining tomatoes”, even though they are not actually vines. They can even reach 6 to 10 feet of height or even taller, and become very heavy.
Therefore, they need support like large, strong stakes or cages, and tying to a structure to prevent the fruit from touching the ground. These plants produce fruit along the stem.
They need to be trained vertically with stakes, cages or trellises, which make them easier to manage and use garden space more efficiently. When they are vertically oriented, they can be grown nearly as close together as determinates. If not staked, indeterminate plants will sprawl across the ground, which is not right for the plants.
They can grow and produce even in that condition. However, they’ll occupy more surface area in the garden and lying on the ground increases the risk of diseases and pests, and of course, accidental trampling.
Indeterminate tomato plants continue to produce fruit that ripens throughout the growing season until frost kills the plants. Thus, they give the grower a slow and steady supply of tomatoes rather than a single big harvest.
However, they start ripening a bit later in the season than determinate varieties as they first take a significant amount of time to grow tall.
Growers often need to cut down some of their suckers to prevent unmanageable growth. However, they should not pinch back a sucker that is just below a blossom as it will cause uneven growth in the plant and also will reduce the harvest.
One can learn to differentiate between determinate and indeterminate tomato plants from their shoots.
Determinate tomato plants stop the production of shoots once flowers are produced on the ends.
Indeterminate tomato plants will keep producing side shoots (also known as suckers), each of which will grow as long as the grower lets it. What’s more, these suckers will grow suckers which in turn also produce suckers. This process continues until the plant dies due to a disease or frost.
Flowers and then fruits are produced along the sides of the shoots.
Differences in Care to be Taken
Determinate types of tomato plants are generally smaller and can be grown in containers. Especially they do well in 5-gallon pots. Thus, they can be grown indoors, on a windowsill, or in a balcony, terrace, patio, or deck. But of course, they can be grown in a garden.
Indeterminate tomato plants normally need a garden bed or larger space to spread out.
Moreover, indeterminate plants can be pruned to only a couple of stems. Otherwise, the plant can turn into a large, unruly mess.
The grower can cut down all the suckers except the one just below the first bunch of flowers. This is required to stimulate the formation of stem and the production of new flower buds for better fruit production.
Pruning of indeterminate tomato plants will improve fruit production and keep the plant manageable and healthier by enhancing air circulation and reducing hiding spots for pests.
Pros and Cons of Both
Determinate tomato plants are not as productive as indeterminate plants are.
But they have a shorter growing season, so, growers will get their tomatoes earlier than the indeterminate plants. Also, they all ripen simultaneously, allowing growers to get a large harvest. Since they grow only to a certain height and then stop growing, they don’t need to be pruned and supported (or need less support); so, they’re a low maintenance plants.
Also, since they die earlier, the gardener can get free space sooner for new plantings.
Due to their growth habit, determinate tomato plants have a lower leaf to fruit ratio, which means they may be less flavorful than indeterminate tomatoes. However, this is not a hard and fast rule. There are several determinate tomato varieties which produce tasty tomatoes.
Indeterminate plants are more suitable to growers who would like to enjoy fresh tomatoes all summer long or even beyond. However, they need to be pruned regularly.
Ideally, a buyer should make sure they buy a few different varieties that have different maturity dates. This will ensure they have a prolonged harvest time.
How to Get Bigger and Tastier Tomatoes from Both?
The right amount of pruning is the key. While determinate varieties need to be pruned only a little to get a larger and better crop, indeterminate varieties need to be pruned often because if they’re not, they lose all their energy into growing new suckers and will have much less energy to produce tomatoes. So, the tomatoes will be smaller and fewer in number.
Research says that pruning lower levels of indeterminate and semi-determinate tomatoes can boost the yield.
Research also shows that vertical training of indeterminate plants improves fruit quality and yield more than horizontal training.
If one is still confused about which variety they should buy, here are some quick considerations.
They should buy determinate tomatoes if they:
- Don’t have a large yard or garden
- Have only a small space
- Live in an area with short summers
- Need to grow tomatoes in containers on deck, patio, balcony, or terrace
- Need a large number of tomatoes at once for canning or making sauce, juice, etc.
They should buy indeterminate tomatoes if they:
- Have a large yard or garden to plant tomatoes
- Live in areas with long summers
- Like to enjoy tomatoes all through the summer or even beyond
But those having their own garden need not necessarily choose only indeterminate tomatoes; they too can plant determinate varieties in their garden. In fact, by planting both varieties, they can enjoy the benefits of both.
On the other hand, those having limited space can also choose to plant indeterminate varieties. They just have to make sure they direct the plant's biomass upward, and then they can grow indeterminate plants even in containers or smaller garden spaces.
Popular Determinate Tomato Varieties
Popular Indeterminate Tomato Varieties
- Early Wonder
- Better Blush
- Celebrity (this is sometimes considered to be semi-determinate)
- Sub-Arctic Plenty
- Scarlet Red
- San Marzano
- Gold Nugget Cherry
- Homestand (sometimes considered to be semi-determinate)
- Heinz 1350
- Amish Paste
- Early Annie
- Super Sweet 100
- Yellow Pear
- German Pink
- Early Girl (often considered to be semi-determinate)
- Black Cherry
- Arkansas Traveler
- Cherokee Purple
- Better Boy
- Big Boy
- Sweet Million
- Matt’s Wild Cherry
- Mortgage Lifter
What about Semi-Determinate Tomato Plants?
Defining a semi-determinate variety is difficult because there is no official definition as to what makes them semi-determinate.
The growth habits of semi-determinate varieties have certain factors similar to that of both determinate and indeterminate varieties.
Semi-determinate tomato plants can be small indeterminate plants or large determinate plants. The only thing a grower can do is to make notes and observations regarding their habits and determine whether pruning will be appropriate or not.
Dwarf and Micro-Dwarf Varieties
Dwarf and micro-dwarf tomato varieties are quite new to tomato lovers. They were actually introduced in 2006.
Most dwarf and micro-dwarf varieties are similar to indeterminates in that they grow and bear fruits until a disease or frost kills them. However, some others are similar to determinates and stop bearing fruit after a certain time.
Dwarf tomato plants are characterized by their short height, usually around 3 feet. They typically have strong, thick stems and thick crinkled leaves. But dwarf varieties come with plenty of options in fruit colors and sizes since the time of the Dwarf Tomato Project (a unique, worldwide collaborative, all-volunteer tomato breeding program for availing great tomato varieties for more and more gardeners.).
Dwarf tomato plants are great fighters against heat and humidity, but they’re still excellent for container gardening.
Micro-dwarfs are much smaller than dwarfs, usually reaching around a foot of height at the most. The plants can spend their entire life in 4-inch pots and hence they are perfect for indoors. They are also great for growing on kitchen counters and in hydroponic kits.
Micros may be one of the most adorable tomato plants one has ever seen. However, they tend to grow and produce very quickly. Some of them even produce tomatoes from seed within 30 days.
Some Terms Tomato Lovers Should be Aware of
Heirloom tomatoes: Any tomato variety that is at least fifty years old and not a hybrid.
Hybrid tomatoes: A tomato produced by crossing different varieties. Hybrids often come with better disease resistance, higher yields, and other improved qualities.
Early variety: A tomato variety that matures in 50-60 days. These are valued for early harvests and late summer planting for a fall crop.
When a gardener struggles to decide which variety they should choose for their garden, the above comparison will help them make the right decision.
They are better off choosing a determinate or dwarf variety if they’re planning to create a container garden or don’t have time for the maintenance of plants. If they want tomatoes from the same plant from July through September or even after that, they’d better choose an indeterminate variety.
But if a grower has time and space, they can enjoy experimenting with both determinate and indeterminate types of tomato plants and see the difference for themselves. And of course, if one has a favorite type of tomato, they can try growing it irrespective of whether it’s determinate or indeterminate.