Friday, May 20, 2011

Tomatoes: Determinate or Indeterminate?

When I attended my recent gardening class, one of the questions someone asked was how to raise great tomatoes. One of the tips given was to first know if you have determinate or indeterminate tomatoes. I had no clue about this. I had never heard that term and I thought a tomato plant was a tomato plant and that the variety might be different, but I didn't know the plants were different.

If you have a determinate, or bush tomato you just let it grow without pruning until it reaches maturity. Determinate tomatoes grow to a certain size and for a certain amount of time and just run their course. A good example of determinate tomatoes are patio tomatoes like Celebrity.

Indeterminate tomatoes are true vines and will grow as long as you pull off the "suckers" that grow between the limbs and they can grow until the weather becomes cool. You should only have about two main shoots that grow very tall. They will also put out fruit clusters as they grow. If they have too many vines on one plant, the fruit will be small. The indeterminate plants will put more into developing the vine than the fruit if you don't pick off the suckers or new vine growths. At least that is the way I understand it.

Up to this point I had always just pulled the suckers from all my tomato plants, but now I am checking to see which are determinate and indeterminate and my "sucker-picking" will depend on that.

I didn't know that my Celebrity tomatoes were determinate before I started the seeds but I probably would not have grown them for the garden. At least I know that my bed with those plants will just be bushy and I will stake it well and not worry about the suckers.

The other two varieties I have in the garden that are determinate are Romas and Green Zebras. I will let them grow as bushy as they want, too.

The rest of my plants are indeterminate, my red heirlooms, Jubilee, Kellogg Breakfast, German Strawberry, Big Rainbow, Purple Calabash will all need to have the suckers trimmed or plucked.

Trimming them is easy. Just look for the new growth between the main stem and the branches and pull it off while small. Below is a drawing I made to show how to pick off the suckers. The little growth shown below, between the stem and branches is the sucker.

Just pick it off or trim it with scissors, being careful not to cut the main stem, branches or the fruit clusters. I hope this helps. I am going to work hard at making sure my plants are properly identified and cared for in a way to give me the highest yield. I think knowing what kind of plant I have is the first step in knowing how to care for them.


  1. I never knew there were determinate and indeterminate tomatoes, but now I am determined to determine the distinction!

  2. Thanks Deborah! Great info.

  3. Thanks Deborah! Great info.

  4. Thanks Deborah! Great info.

  5. Thanks Deborah! Great info.