Determinate and Indeterminate Tomatoes

Understanding Determinate and Indeterminate Tomatoes

If you picture a vegetable garden, odds are good that it includes tomatoes. These plants are the No. 1 home garden crop in the U.S., according to the National Gardening Association. We suspect that’s because few things compare to the amazing taste of a ripe, fresh tomato.

If you’ve been thinking about growing tomatoes yourself, one of the fundamental choices you’ll need to make is whether to grow determinate or indeterminate varieties. Each type has unique characteristics, affecting everything from space requirements to pruning techniques and yield. 

So, what exactly are determinate and indeterminate tomatoes?

Determinate tomatoes (bush tomatoes)

Growth

Determinate tomato plants are more compact and bush-like. They tend to grow to 3-4 feet and stop.

Fruiting pattern

If you grow determinate tomatoes, you should plan for the fruit to ripen roughly around the same time, over a few weeks. That makes them a good choice for preservation. (They’re also great for making sauces because they have fewer seeds and more flesh.)

Pruning and maintenance:

Because their growth is contained, determinate tomatoes don’t need much pruning, though they might benefit from some light pruning to improve air circulation (which helps reduce the risk of mold and disease).

Space requirements

If you have limited space, determinate tomatoes could be a good choice for you. They work well in container gardens and small gardens.

Examples of determinate tomato plants include Roma, Celebrity, and Bush Early Girl.

Indeterminate tomatoes

Growth

These vine-type tomatoes can reach heights of 6-10 feet or more. They need sturdy support like tall stakes, trellis, or cages.

Fruiting pattern

Indeterminate tomatoes will keep producing fruit for you throughout the growing season, a plus if you’d like to enjoy fresh tomatoes over a longer time.

Pruning and maintenance:

Plan to prune your indeterminate tomatoes regularly to remove suckers (side shoots) and encourage healthy growth and better fruit production.

Space requirements

Indeterminate tomato plants can get pretty large. If you want to grow them, you’ll need plenty of space and support structures.

Examples include cherry tomatoes like Sweet 100, beefsteak tomatoes, and heirloom varieties like Brandywine.

Growing conditions

When it comes to growing conditions, determinate and indeterminate tomatoes have similar preferences — with a few notable differences.

Take soil requirements, both thrive in well-draining, fertile soil with a pH level (acidity) between 6.0 and 6.8. And both will do better if you enrich their soil with organic matter like compost or well-rotted manure before you plant them. But, while compact determinate plants can benefit from heavier soil to support them, indeterminate plants prefer lighter, well-aerated soil to accommodate their extensive root systems and continuous growth.

As for sunlight, all tomatoes need full sun, at least six to eight hours of direct sunlight a day. If that isn’t possible, you’re more likely to get away with planting determinate tomatoes in slightly less sunny spots since they have a shorter growth cycle.

Both types of tomatoes need consistent, deep watering to encourage deep root growth. Aim to water your plants at their base so you don’t get their foliage wet, which can lead to disease. It also helps to apply a light coat of mulch on the soil to help minimize evaporation.

Because tomatoes are heavy feeders, meaning they need a lot of nutrients to grow and produce fruit, you should plan to fertilize them. A balanced fertilizer is your best choice when you plant them. If you’re growing determinate tomatoes, that probably will be enough to get them through their relatively short growing season. But indeterminate varieties will need regular feedings. After your initial application of balanced fertilizer, switch to a formula that’s higher in phosphorus and potassium.

Spacing guidelines

When you plant, space your seeds or seedlings according to the directions on their packets or labels. 

Generally, you should space determinate tomato plants 18-24 inches apart to give them room for airflow and growth. Also, plan to leave 3-4 feet between rows so you have enough room to move between them for watering, pruning, and harvesting.

Give indeterminate plants more space, 24-36 inches, since they’ll grow larger and need more room to spread. Leave 4-5 feet between rows.

Harvesting your tomatoes

Determinate

Remember, your determinate tomatoes will produce one concentrated harvest over a few weeks. Monitor your plants closely once the fruit starts ripening. Your tomatoes will be ready for harvest when they’re fully colored (depending on the variety, this could be red, yellow, or another color) and firm, but give slightly when pressed. To harvest them, use clean, sharp scissors or pruners to cut your tomatoes off the vine. Leave a small portion of the stem attached to help prevent damage to the fruit and the plant.

Indeterminate tomatoes

Begin harvesting when your tomatoes are fully colored and slightly firm. Don’t leave them on the vine too long, or they might get overripe and attract pests. Inspect your plants every few days to harvest ripe tomatoes and encourage your plants to produce more fruit. When you harvest, just like you would with determinate plants, use sharp scissors or pruners and leave a small stem attached to the fruit.

A general tip: Store your harvested tomatoes at room temperature. Refrigeration can affect their flavor and texture.