Sunday, 28 March 2010

Tomato: Determinate vs. Indeterminate

What's the difference between "indeterminate" and "determinate" tomatoes?
Determinate tomatoes, or "bush" tomatoes, are varieties that grow to a compact height (generally 3 - 4'). Determinates stop growing when fruit sets on the top bud. All the tomatoes from the plant ripen at approximately the same time (usually over period of 1- 2 weeks). They require a limited amount of staking for support and are perfectly suited for container planting.
Indeterminate tomatoes will grow and produce fruit until killed by frost. They can reach heights of up to 12 feet although 6 feet is normal.  Indeterminates will bloom, set new fruit and ripen fruit all at the same time throughout the season. They require substantial staking for support and benefit from being constrained to a central growing stem.

So how do you decide what's best for your garden?
If you have a large garden, and would like heavy crops of tomatoes at certain points in the season, you might want to plan for several determinate varieties. You would look for two basic pieces of information in the plant catalog or on the plant label when making this decision. Look for the word "determinate" or the abbreviation "DET" so you know what you're dealing with. Next, look for the number of days at which the plant will set fruit. To get several nice harvests, try to combine determinate varieties that bear early, mid, and late season crops. If you are into canning, saucing, or drying your tomatoes, this is probably the best way to go.
staked indeterminate tomatoes
If you want tomatoes for the course of the season for snacking and adding to salads and sandwiches, it is best to go with indeterminate varieties. Several types of indeterminate tomatoes are very prolific, and a plant or two will more than suffice to meet your needs. Many favorite heirloom tomatoes are indeterminate varieties. When shopping for your tomato plants, you will be looking for "indeterminate" on the label, or the abbreviation "IND" (or, less commonly, "INDET").
The majority of tomato varieties are indeterminate including most heirlooms and most cherry types. Other indeterminate tomatoes include: 'Beafsteak', 'Big Boy' and 'Brandywine'. Early producing varieties like, 'Celebrity' and 'Early Girl', are also indeterminate. However since they tend to mature earlier and die back before the end of the season, they are sometimes labeled semi-determinate.
If you want to grow in containers, you'll probably want to stick with a few different determinate varieties, see right. They are more well-behaved and better suited to container culture.
You can certainly grow indeterminate tomatoes in containers, but be prepared to be vigilant about staking or caging, as well as pruning the suckers to maintain compact growth.

Many paste or roma tomatoes are determinate varieties. Some others bred to be determinate include: San Marzano (see left), Celebrity, Marglobe and Rutgers.
Growing determinate variety tomatoes makes good sense when you want a large amount of tomatoes all at one time, to make tomato sauce for example.

1 comment: