Tomato Suckers: What Are They and Pruning Them

I’ve developed the habit of pruning the suckers off of my tomato plants as they grow, with the purpose of helping the main stem to grow stronger. Suckers develop in the crotch of the stem and a branch, as illustrated:

suckers on tomato plant
suckers on tomato plant

For a while I thought that these suckers would just become branches that didn’t even produce any fruit, just sucking energy from the plant, but that isn’t true – they do fruit.

It seems there are contradicting thoughts on whether suckers will produce or not. Some people say they do not blossom and fruit.

I also tend to snap off the bottom leaves when they start to yellow and look bad, and any additional little suckers growing on the stems below that first set of leaves.

Now I wonder if I’m pruning too much! I think I’ll stop pinching off the suckers, now that my plants are blossoming on top.

Here are my two greenhouse tomatoes about a week ago- Brandywines. I reckon I should stake them soon:

Brandywine tomatoes growing in pots
Brandywine tomatoes growing in pots

I’m curious if you guys prune your tomatoes, or if you just let them do whatever. Have you had more success one way or another?

19 thoughts on “Tomato Suckers: What Are They and Pruning Them”

  1. The fruit on determinate varieties of tomatoes all get ripe at about the same time. They are usually your bushier tomato plants & you would generally use them for making sauces, etc. We grow Roma tomatoes because they are determinate and I can get enough at one time to can for tomato sauce, pizza & spaghetti sauces. We don’t prune (sucker) our determinate tomatoes and they don’t usually need tomato cages. Indeterminate tomatoes are the ones that produce their tomatoes over the whole season, up until frost, and the plants grow much taller than determinate varieties. We prune our indeterminate tomatoes and have to put cages around them.

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  2. Determinate means “determined” size of growth, or, a specific size. Indeterminate is an “undetermined” amount of growth. That means it keeps growing, and growing, and growing….. ;>)

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  3. I let the tomatoes do whatever they want. I figure they’ve been around longer than I, and know what they’re doing. My caveat though is that I don’t do a ton of long-season or indeterminate tomatoes. They just don’t throw a lot of fruit up here – I have to stick with early-season and determinate tomatoes for the bulk of what we grow.

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  4. I read somewhere that you prune the suckers that grow below the first set of flowers, but anything higher, leave on and they will produce fruit. Had a pretty good crop last year doing that, but can’t say whether it was better than other years. Happy tomato growing!

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  5. Prune! Like all fruit bearing plants, proper pruning leads to better fruit production! If you want more tomatoes, its best to get more plants than to allow one plant to produce more tomatoes that are not as good as they could be if it was pruned so the plant could focus on fewer, yet better quality fruit. I have left suckers (before I knew about pruning) and they have made some fruit, but I think you get a better plant when you prune. And snipping the yellow leaves on bottom isn’t really a harmful thing. They will fall off anyway.

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  6. Brandywine is sure indeterminate, Celebrity is said to be determinate (I have not grown it yet, not sure), you can Google the others if you do not have the seed package anymore.
    But even if you are not sure, just gave them some time. If the plant stops growing after setting out flowers, it is a determinate plant. They (usually) stop growing when fruit sets on the terminal or top bud, ripen all their crop near the same time, and then die.
    Indeterminate grow tall, bloom, set new fruit and ripen fruit throughout the whole growing season.
    I hope this is helpful.

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  7. If your tomato plants had tags when you bought them, the tag should have told you if they were determinate or indeterminate.

    Try checking here: http://davesgarden.com/, under guides and information. They listed the Park’s Whopper as indeterminate. They may have the others there, too. :o)

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  8. Yellowing leaves is calcium deficiency. Add egg shells or spoiled milk or whatever else you have available to add calcium. Also helps in preventing blossom end rot.

    What is determinate and indeterminate?

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  9. Anna (or anyone else),

    How do you determine whether a tomato plant is derminate bush or not? I purchased the following: 1 Brandywine, 1 Celebrity & 1 Park’s Whopper and started the rest of my varieties from seed (German Cherry, Reinstaldt(sp?) Grape, Pruden’s Purple, Oxhart Yellow, Rutgers’s, Hillbilly & Marglobe). Are any of them Derminate?

    Thank you in advance.

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  10. I never knew to “prune” tomatoes any way! This is our first year actually growing tomatoes from seed (we usually just buy the plants). Some of our leaves are turning yellow, towards the bottom? I’m guessing that’s normal? We have no clue what we are actually doing, an experiment as usual! lol!! Can’t wait to put ours in the ground though! We still have a few weeks.

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  11. Determinate “bush” tomatoes should not be pruned, only indeterminate need to be pruned.
    HINT: If you place the cut of suckers in water, they will produce roots and grow into a new plant.

    Keep on growing :).

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  12. No,don’t stop. Keep getting rid of the suckers. Having the plant open like that gives it air and sunshine. The plant will get much fuller, and it won’t waste energy on the extra plant, it will spend it making the tomatoes. Also, keeping it open, reduces the chances of diseases. I keep pruning the suckers right up until harvest time.

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  13. Yes I prune the suckers off always. I do get better plant growth and production from my plants now than before I knew to do this pruning.

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  14. I pull the suckers off when the plant is getting too bushy, blocking air circulation, but it sounds like you’re more diligent than I am.

    Last summer I started re-planting the longer suckers. If you put them right into soil, they’ll grow into new tomato plants.

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  15. We do “sucker” our plants, but no further pruning other than that. We grow a HUGE volume (at least 50 plants), so we do just the once over. We suckered for the 1st time last year and I do believe we ended up with larger fruit, as opposed to the year before when we didn’t sucker them.

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  16. I don’t prune until they are crazy tall. Then I go out and cut all the branches that aren’t producing. I didn’t do this for the first 2 years but last year I discovered that they grew crazy amounts of tomatoes when I did prune the branches. I’m by no means an expert. Lol. But I did have great results last year.

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