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You probably have heard the terms “determinate” and “indeterminate” applied to tomato plants and wondered what they meant. The differences are not mysterious; they are all about the way different tomato plants grow. We’ll explain.
Determinate Vs. Indeterminate Tomatoes
To get to the short answer …
Determinate plants are “bush” tomatoes and only grow until they reach a fixed size. (Think: a “determined” size.) These plants are small and bushy and tend to produce all their fruit within a few weeks.
Indeterminate plants are “vining” tomatoes and continue to grow with no fixed size. (Think: “indefinite”). They are huge vines sprawling 6 to 10 feet long or more and will keep producing tomatoes until frost hits and they die.
Differences go beyond how they grow. Determinate and Indeterminate Tomatoes are different in terms of harvesting and cooking, as well as how they are supported/trellised, how they are pruned, and garden space needs.
For beginners, determinate tomatoes are best. They only require staking, not a complex trellising system. We’ll get more into the differences below so you can choose the option that’s best for you and understand the reasons why.
All About Determinate Tomatoes
The size of determinate plants has been predetermined by genetics. Most varieties will grow about 2 to 3 feet tall; some may get as large as 4 feet, but that is about tops for height.
Most don’t require any kind of support, though they often do better if they are staked or caged.
The plants tend to stop growing after forming fruit.
They produce most of their fruit in one or two flushes over a short span of time, and then they are done for the season.
Due to their compact size, they are excellent for small gardens or for growing in containers. This is one the main considerations for determinate vs indeterminate tomatoes. If you are in search of large, flavorful slicers, then indeterminates may be a better choice for you.
If the word “bush” is in a variety of names, chances are good that it is determinate.
Their fruit is often the first to ripen in the garden.
Many paste tomatoes, such as ‘Roma’ and some old favorite slicers, including ‘Rutgers,’ ‘Marglobe,’ and ‘Celebrity’ are determinates.
All tomatoes are sun lovers! Pick a location with 6 to 8 hours of direct sunshine.
It’s always best to select disease-resistant tomatoes. It’s always hard to know which disease, so select a variety with “VFN” after the name.
Tomatoes are hungry plants; make sure you mix in organic matter and fertilizer when you prepare the soil. Many tomatoes don’t get enough nourishment if the soil fertility is too low. You’ll need to re-up the feeding with a balanced fertilizer after fruit set—mix into the soil every week.
Stake tomatoes right away to keep the fruit off the ground. Or, use a tomato cage.
A few weeks after planting, mulch!
Check daily for pests or diseases so you can immediately address them.
Never prune down determinate plants! They form flowers and fruit only at the tips of their branches. If you prune the suckers, you will cut off your future fruits and have lower yield.
Harvesting Tips
As mentioned above, determinate tomatoes ripen in a few weeks for a defined harvest period. This is especially helpful if you want to use tomatoes to make a sauce or other recipe.
All About Indeterminate Tomatoes
Instead of bushy growth, indeterminate plants are huge vines sprawling 6 to 10 feet long or more.
The vines will keep growing until killed by frost.
Instead of ripening all at once, indeterminate tomato plants produce a steady supply of fruit throughout the growing season.
Though their growth may slow down later in the season as daylight wanes and nights cool off, they will continue to blossom and set new fruit.
Many are late varieties which, if you are patient, will reward you with the largest and most flavorful fruit.
Due to the higher leaf-to-fruit ratio and long ripening time, they have time to develop a sweeter and more complex flavor. According to University of Florida’s Gardening Extension, most types of cherry tomatoes are indeterminate which is why they often have a sweeter flavor.
Most heirlooms and open-pollinated varieties, including ‘Brandywine’, ‘Delicious’, ‘Black Krim’, and ‘Cherokee Purple’, are indeterminates.
Growing Tips
Indeterminate tomatoes will definitely need some kind of support, such as stakes, tall, strong cages, or trellises. Look for large cages at least four feet tall and reinforce them with wood or bamboo stakes. Other good support materials include wooden or metal rebar stakes with additional twine or twist ties.
Pruning Tips
If your indeterminate tomato plants get so high that you can’t support the plant anymore, you need to top them off.
If you wish, you can pinch out suckers as the plants grow or prune the growing tips of the tallest vines to keep them in bounds without sacrificing all your fruit production.
For bigger tomatoes, remove the suckers, leaving two to three suckers.
Cut out lower branches or any branches that touch the soil.
Harvesting Tips
As indeterminate tomato plants just keep producing until fall frost kills the plant, keep harvesting regularly to keep the plants producing! Pick tomatoes when they are red or the right color and slightly soft to the touch.
Pros and Cons
Indeterminates have larger fruits. Determinates will have earlier fruits
Indeterminates are strong enough to recover from early diseases and form new growth. If hit with early diseases, determinates will not recover.
Determinants give you an early harvest so you can pull the plants when they are done to make room for fall crops. Indeterminate fruits ripen over a long period of time and will continue to grow until killed by frost, taking up a lot of room in your garden.
Indeterminates can be pruned if necessary. Determinants need no pruning.
What is the Right Plant for You?
Characteristic
Determinate Tomatoes
Indeterminate Tomatoes
Growth
Small and bushy, grows to a set size
Huge vines sprawling 6 to 10 feet long
Harvest
Produces fruit in a short period
Produces fruit continuously throughout the season
Size
Typically grows 2-4 feet tall
Can reach 6-10 feet or more
Support Needed
Minimal (staking or caging optional)
Requires strong cages, trellises, or stakes
Flavor
Often ripens earlier, ideal for sauces and bulk use
Sweeter and more complex, ideal for slicers
Best For
Small gardens, early harvest
Long harvest, large flavorful tomatoes
Personally, I think both indeterminate and determinate tomatoes have desirable qualities so we grow some of each.
The Roma paste tomatoes to get a large quantity at once for sauces and some small determinate plants to grow in containers near the house.
When I need a tomato in a hurry it is great to have them close at hand. Otherwise the heirloom indeterminates are worth the wait. Their flavors are so delectable. They are the backbone of our tomato patch giving us fruit all season long.
Still Can’t Decide?
Some tomato varieties are classified as semi-determinate or semi-bush, which have traits of both determinate and indeterminate plants.
They bear their fruit over a concentrated period of time like a determinate, but the plants grow a bit larger.
Since they produce more branches, they will need more support like an indeterminate but will also produce more fruit
Some semi-determinates are ‘Homestead’, ‘Marmande’, and ‘Celano’.
There is no single type of tomato that is perfect for everyone. If you are still undecided on the determinate vs. indeterminate tomato debate, try some of each and see what works best for you!
Whichever tomato you choose, they have common needs. Remember that it needs 6 to 8 hours of direct sun a day. Water consistently to prevent issues such as blossom-end rot and cracking. The fruits are 95% water! Steer clear of high-nitrogen fertilizers. They will make for lots of leafy growth but few fruits. Make sure your soil has sufficient potassium. It is the nutrient that governs the amount of fruit you get when it ripens, and its sugar levels.
I am sold on indeterminate tomatoes; it's all I ever plant anymore. The abundant, continuous harvest is well worth the trouble of providing support (a cattle panel arch works perfect for me). It is hard to find indeterminate sauce tomatoes, but my reliable favorite is called "Gladiator Hybrid" from Burpee. Almost identical to Roma, they are large and flavorful fruits. The only drawback is that as a hybrid, you can't save the seeds. If you try, the resulting plants produce very small fruits. Tip to take advantage of the continuous production: after you start picking, keep them in the refrigerator to slow further ripening (or even freeze them) until you have enough for your desired batch size for canning. A side benefit of freezing is that is makes peeling a snap - the peels will slide off easily as the outside first begins to thaw.
For indeterminate sauce tomatoes look for heirlooms. We have grown Amish Paste, Hog Heart, Opalka, Jersey Devil, Grandma Mary, and Coure di Bue with great success, so much so that it is hard to narrow the choice down to just one ! All are open pollinated so you can save the seeds and all are meaty and delicious.
The seed packet should tell you (sometimes it is abbreviated as Ind. or Det.) but if it lacks that bit of info, the word bush is a giveaway that it will be a determinate. Double check in a seed catalog or online just to be sure before you make your purchase.