To remove or not to remove? The mysterious world of tomato suckers is about to make sense to you. What they are, how to identify them, when you should remove them and when you should leave them.
I learned how to identify a tomato sucker when I was a kid in the garden with my father. Whether to get rid of these secondary stems is a bit of a game with no absolute YES or NO.
It was in that garden as a child that I also learned some of my most cherished swear words.
Part of the confusion with suckers comes with the name. A tomato sucker isn't a typical sucker like you'd see on a fruit tree or shrub. Those true suckers grow out of the roots and SUCK energy from the plant. Hence the name.
I have a unique tip on how to prune zucchini plants as well.
So what exactly is a tomato sucker other than a topic to be avoided at pot lucks & prisons because of its obvious controversy?
Table of Contents
What's a tomato sucker?
A tomato sucker is an actual stem or leader that grows between the main stem and a leaf of the plant. These stems will get very large, flower and produce tomatoes. All tomato plants get suckers. (unless there's some new genetic mutation I'm not aware of)
If they produce tomatoes why would you ever get rid of them? Mainly because they can be transform a perfectly well mannered tomato plant into a gigantic, hungry, aggressive monster.
How to Prune those Suckers
- Stare at the main central stem of your tomato plant. Follow it up from the ground. Everywhere a leaf pops out of the big main stem, check to see if there's something else growing out of the "V" between the stem and the leaf. (see the photo above)
- THAT is a sucker. Pinch it off.
- Continue doing this all the way up the main stem.
- If your tomato plant is overgrown and FULL of big, grown suckers don't remove more than 30% of the plant's greenery in one shot. It will shock the plant. Just do a bit, then come back a few days later and do more.
HOW MUCH TO PRUNE OUT
Never remove more than ⅓rd of the plant's vegetation at a time. It'll put the plant into shock and the leaves will curl up. Remove a bit and come back after several days and remove some more.
SHOULD you prune suckers?
Get rid of suckers on indeterminate (heirloom) tomato plants. Keep suckers on determinate (hybrid) tomato plants. That's the elevator pitch.
WHY?
INDETERMINATE PLANTS (heirlooms) get HUGE. Your indeterminate tomato suckers can become 8' long. If your indeterminate (heirloom) tomato plant grows, let's say - 10 suckers, that are each 8' long, you can imagine the mess of a tomato plant you'd have.
Even though the suckers WILL produce tomatoes, they won't be as big or healthy as you'd like.
REMOVING SUCKERS - gives the plant better air circulation, allows more sunlight onto the fruit & reduces the amount of soil resources (all the good minerals and fertilizers) the plant uses up.
Would you like to save this stuff?
We'll email you this post, so you can refer to it later.
DETERMINATE PLANTS (hybrids) are more reasonably sized that quit growing after they reach a certain size. Usually about 5' tall. That means their suckers don't use up as much energy or get as wild as those on an indeterminate. Which in turn means you can keep them and use the suckers to your advantage (more tomatoes) without sacrificing the health of the tomato plant.
To learn how to train your tomatoes up a string read my post on string trellis training.
Other pruning you need to do
For a healthy tomato plant you ALSO want to remove the leaves on the lower third of the plant. Any leaves that sit below the lowest cluster of flowers/fruit on the tomato should be removed.
These leaves aren't doing anything to help support the plant or the tomatoes it's growing. They're just sucking energy and increasing the chance of disease.
This is because tomato disease like blight is spread from the soil below the plant splashing up onto the leaves. Get rid of the lower leaves and you help get rid of the problem. Mulching with straw or wood chips below the tomato plant helps with that too.
What happens if you don't follow the pruning "rules"
I hear you. You don't like rules. Neither do I. You can either get rid of none of the suckers, all of the suckers or some of the suckers. Nobody is going to report you to bylaw. Or the warden.
*Getting rid of none of the suckers will create a big tangle of a tomato mess. You'll have a lot of tomatoes, but they'll be small. Also, there's less air flow in the plant and more leaves that make it more susceptible to disease like blight.
* Getting rid of all of the suckers and only keeping the main stem will give you the least amount of tomatoes. You'll get large tomatoes, but not many of them. Also, tomatoes get their sweetness partly from the leaves so the less leaves there are the less delicious your tomatoes might be. Technically speaking.
* Getting rid of most, but not all of your suckers is the way most smart people like you and I go. Leaving 1 or 2 suckers along with the main stem of an heirloom will give you a strong plant, less susceptible to disease and a good amount of tomatoes. It will result in the healthiest tomato plant. And pruning away about ⅓rd of the suckers on hybrids will give the plant better air circulation and allow light to hit the growing fruit accelerating their ripening.
So yes. I said it. You don't HAVE to follow the rules. This of course is why this is such a volatile topic in prison gardens.
The only thing I'd say is I would NEVER prune all of a hybrid plant's suckers. Removing a few of them for better air circulation isn't a bad idea though.
And I'd NEVER let all the suckers grow on an heirloom tomato. It just becomes a terrifying tangle of greenery.
The best time to prune suckers is when they're small. Check the plants every few days. As soon as you see them start to grow pinch them off. A sucker won't regrow in the same place once it's pinched off.
Yep. Even without all those suckers, tomato plants get really heavy so use the string trellis method for supporting heirloom tomatoes and I like the Florida Weave (see below) for hybrids.
Now that you have that all figured out you can spend the rest of your day sharing your newfound information with fellow prisoners or family members.
Nancee
Great post! I have 2 tomato plants that sprouted in my worm bin. I put one in the bottom half of a small water bottle and put it on my kitchen window ledge and forgot it. The darn thing keeps growing! I don't like growing tomato plants, but now that I have 2 that refuse to go away, I'll keep your tips in mind.
And I won't be taking any photos of myself...I already know I look like a lunatic as well.
Jenifer
Where are all of your weeds??? Do you weed your garden daily? I have to lay lay down thick pads of wet newspaper and then cover with straw...NOT a fun process or buy rolls of ugly plastic and even then....Plus, we've had a ton of rain lately which helps the weeds and prevents me from pulling them. (I cannot weed in the rain. I'm a big baby.)
How do you not have more weeds?
Barbara
Read Ruth Stout's GARDENING WITHOUT WORK
Jenifer
Thank you! I definitely will. :)
KowboyK
Here in Cali, my tomatoes are already 7' tall & I have been harvesting a few here & there since the first weekend of this month. A good friend recently tried to show me how to prune, but your directions are much easier to follow. These behemoths are gettin a haircut tonight after work!! Thanks for the all the pictures & drawings, they made it all make sense.
mayr
A most excellent post with equally excellent comments. Thanks so much for this info.
vieux bandit
You can turn those suckers into a tea -- not to drink, but to give back all their nutrients to your tomatoes. I'd explain how, but you're a smart cookie who can google it for yourself and I'm badly in need of my first coffee (yes I read you before coffee. That's how much I care.)
Carlette
Thank you SO much! I've been growing tomatoes for about 7 years, and pinching off little suckers and letting the tomatoes take over the whole yard. I had memories of my grandmother's tidy little compact plants and couldn't figure out what I was doing wrong. This made it much more clear.
For reference, I pulled out a plant at the end of the season that had gone up its stake, and back down, and crept along the ground, it was about 12 feet long, and the base was as thick as my wrist! And I have thick, cornfed, farmgirl wrists.
As soon as it stops raining, I'm going out there and taming those little bastards!
Karen
Hi Carlette - Once you get nearer the end of the season you can also pinch off the top of the plant. This will both stop unwanted top growth and help ensure that the tomatoes that are on the vine will ripen before the frost gets it. (do this about a month before your potential first frost date) ~ karen!
Karin
Now let's see those green stained thumbs from pinching off all the suckers! At least that's what always happens to me and I smell like a tomato for the rest of the day. I too tried the Florida weave one year but my tomato plants grew at such different rates it was hard to do. One plant would be ready for the next weave and another would barely be up to the previous weave. If a sucker has started to flower can your pinch it back or should you let it grow? I got lazy last week...
Karen
Hi Karin. It makes no difference. If you want to pinch off the sucker that's flowering, pinch away. It's usually better to pinch them before they flower just because they're smaller and removing a smaller branch is easier for the plant to heal. ~ karen!
Bre
I have a gardening friend who refers to the suckers as "crotch tomotoes." The crotch tomatoes gotta go. And now you'll never not remember which stems get pruned. :)
michelle r
Great tips about the tomatoes but it will only take me a few minutes to prune mine as I have only one plant.....On another note, wonderful article in the Costco magazine, I didn't know your father made his own screws. No wonder you're a DIY diva!!!
Laura Adams
Thanks for the information about suckers, something that has always been a bit mysterious to me. Now I know. Do you continue the weave technique up the post as the plants grow?
Karen
Hi Laura! Yes. I should have mentioned that, lol. As the plant grows you continue with your weaving. :) ~ karen!
Beckie
I always used to grow hybrid tomatoes of a determinate variety. A few years ago I had an indeterminate heirloom tomato plant we ended up naming her Audrey, after The Little Shop of Horrors. (to compound confusion, my late mother's name also happened to be Audrey. This has nothing to do with my tomato plant story) So, anyway...Audrey apparently liked where she was planted and she grew...and Grew...and GREW. I had 12' tall 1x2" stakes, she grew taller. I lashed 2 stakes together (so I had maybe 22', in total, to account for the part stuck in the ground and the part where the stakes overlapped) she grew taller.
I was already needing to stand on a ladder to tie up the top part, I couldn't go any higher with the stakes, so I lopped off the top of the plant whereby Audrey decided to grow out in the fashion of a weeping cherry tree and became a sort of tomato plant canopy that hung over the garden gate.
That was the year I learned the difference between a determinant and indeterminate tomato plant.
She gave me about a dozen tomatoes...and a story.
I now prune...and keep the top in check. Thanks for the reminder. I need to get on that, pronto!
IRS
Whenever I prune tomato plants, I love the smell of the leaves. It always makes me want to eat them as a salad green, but I have always read that they are poisonous. Recently, I read for the first time that they are NOT poisonous. So which is it? Does anyone here know the answer? Ms Karen, any thoughts?
Mary W
I believe they are part of the nightshade family and the leaves are poisonous. People used to think tomatoes were poisonous and didn't eat them but found they could. I know that poke weed berries are very poisonous but the tender spring leaves are used in salads. The older leaves are poisonous. Potato and squash leaves are poisonous and I used to rub them over my horses backs during the summer to keep the biting flies away and it worked. But this had to be done every day since it rained here in FL every day.
Karen
I don't eat tomato leaves but my guess is they aren't actually poisonous. Or if they are, it's along the lines of green potatoes. They contain a trace amount of poisons but you'd have to eat an insane amount to actually get sick from it. I myself have tasted tomato leaves and didn't keel over. ~ karen!
IRS
Thanks for weighing in Karen. This actually reminds me of rhubarb, which you have written a lot about. We have all been told that the leaves of rhubarb are poisonous, but I have wondered how that actually works. If you cut the leaf off right where it meets the stalk, in order to maximize your rhubarb yield, it seems rather strange that Mother Nature would have the toxins stop at that exact point. Few things in nature are that precise. And then of course there is the question of certain greens/plants that are toxic when raw, but not when cooked. I learned that the hard way when I ate some lovely sprouted red kidney beans. I spent a LOT of time in my bathroom that day, uttering words that even I rarely use.
Daphne
Well, you wont die from eating a small tomato-leaf salad, but your stomach will give you a very hard time the following hours/days. One of the reasons most animals stay away from your tomato plant. Except for the chickens, of course, and slugs. Both animals with steel guts.
Sandi
The word "sucker" has begun to sound very weird in my head.
Karen
Ha! ~ karen
Jan Lane
Karen, have you ever rooted the removed suckers in a glass of water on the window sill? I have tried this this year and now have 3 new blooming plants. If it works I will never buy tomato plants again!!!
Karen
I have indeed. :) I did it to try to grow cherry tomatoes on a windowsill in the winter, not to harden off and plant out in the spring but I don't see why you couldn't. ~ karen!
Lauren
Excellent info! The only thing I have a question about is this: Within the heirloom classification there are mainly two different types of tomatoes - determinate and indeterminate. I have always heard that you can prune the indeterminates if you want, but that it's NOT beneficial to prune the determinates. Doing so would decrease the harvest because determinates stop growing when the main stem sets fruit. Any insight into pruning determinates versus indeterminates?
Carswell
Indeterminates - which most heirloom tomatoes are - just keep growing as long as the season lasts. Each sucker can grow, flower and set fruit as the season progresses. That's why you can prune them.
Determinates - which are hybrids - are the ones that grow more bushlike and pretty well stop once they've set the first flush of fruit.
Carswell
Forgot to add - Karen's plants above are indeterminates - which grow best on tall poles like that.
Karen
(there are some determinate heirlooms as well Carswell ... normally they're what's referred to as the New Heirlooms, like Green Zebra) ~ karen!
Karen
Yup. That's true. All heirlooms are either determinate or indeterminate but all indeterminate are heirlooms. However having said that MOST heirloom tomatoes are indeterminate. Very few are determinate. When I refer to not pruning hybrids, I should have also referred to not pruning determinates. There's no need. So treat determinates the way I say to treat hybrids. Just let them do their thing. ~ karen!
Julie
Sorry Karen, not all indeterminates are heirlooms...many hybrids are indeterminate as well...I grew tomatoes commercially for a couple of seasons, and those were definitely hybrids...and definitely indeterminates!
Karen
Yup you're right. ~ karen!
Daphne
SuperSweet 100 F1 is a hybrid. And an indeterminate. And a monster if you let it grow. I grew one once. I had to decapitate (is that good English?) it when it reached the ceiling of my greenhouse (3m). It strangled its two neighbour maters on its way up and to the sides. But maybe we must look at cherry tomatoes as a whole different kind of tomato plants.
brenda
i don't even know what I know now anymore … but I am going to try all of this on my 30+ tomatoes … maybe 40+ (once I planted 78 or maybe 84 tomatoes (I lost count and all the tags by the end of it that year) … this year I put the list of who's what on a piece of paper and the paper is somewhere … and I can too). Are we really tomato lunatic selfie ladies if we do that? hmmmm … I did not now that either ;)
Laura
Except i LOVE the smell of tomato leaves!! This was such a useful post. And you are pretty hilarious i have to say!
Kathy
I did t know that more leaves give a better tasting tomato!
Paula
This year, I am doing exactly as you are doing except I am trying out the Mittleider Tomato support system. I have over 60 plants (I know - what was I thinking!). My thought process at the time was: try 10 different types growing them all from seed, however; I honestly didn't think that they would all survive. I can't throw out a perfectly good plant, so I have lots of tomato plants. I am pruning to one main stem though, so that should help with the oncoming tomato onslaught. I can, too and I did 3 bushels last year.
Edith
Hi Karen,
How interesting! I never knew this about heirloom tomatoes. Your community garden looks like so much fun. You ought to give us a tour of the whole garden sometime. It looks like there will be a huge harvest going into fall.
Robert
I never thought tomatoes were so lively, they sound like a wonderful pet
Kat - the other 1
So tomatoes are pets and chameleons (according to my sister) are houseplants?
Lol 😆