Top 3 Reasons Why Your Tomatoes Are Not Setting Fruit

, written by Benedict Vanheems gb flag

Tomato flowers not setting fruit

Are you picking plenty of tomatoes this season? If not, take heart in the fact you’re certainly not the only one. A lack of fruit set – when flowers fail to produce fruits before they wither and drop – is one of the most common complaints among tomato growers. It’s frustrating and it’s not fair, particularly given all the attention you’ve no doubt lavished on your plants to get them this far.

Whether you’re yet to pick a solitary tomato, or your plants have abruptly stopped producing, the reasons behind the lack of fruit are often predictable and easy enough to fix. So don’t despair – read on and see if your plants can be persuaded to behave.

Tomato flowers with tomato fruit setting

1. Insufficient Pollination

The first thing to consider is how easy it might be for pollinating insects to reach your crops. Tomatoes are self-fertile, which means each flower can pollinate itself. Nevertheless, the presence of bees and/or wind dramatically improves pollination by nudging the flowers just enough to help dislodge the pollen from the stamens.

Bumblebees are especially good at this. As they contract their flight muscles (a process called 'buzz pollination') these low vibrations literally shake the pollen free, allowing it to drop down onto the stigma – the female part of the flower that catches the pollen.

If you’re growing tomatoes in a greenhouse or polythene tunnel it may be worth considering whether pollinating insects have ready access to the plants. Open up doors and vents, which will also help to create a good through-flow of air, keeping plants cooler and reducing the risk of disease.

You can artificially pollinate tomatoes by lightly shaking the plants yourself to mimic the bee’s buzz. Twang string-lines or canes supporting vining tomatoes, or lift and drop (gently, from a very short distance!) container tomatoes.

Tomato flowers

2. High Heat Levels

In hotter climates, high temperatures can sometimes play havoc with pollination. Hot spells, when daytime temperatures remain above 30ºC (86ºF) and, crucially, nighttime temperatures fail to dip below 24ºC (75ºF), have the undesirable effect of turning pollen sterile. Turns out tomatoes like it hot – but not too hot!

The only thing you can do during a heat wave is bide your time. In the meantime keep plants well watered and healthy, so that when temperatures finally subside they’ll be in an excellent position to ramp up production once more.

Don’t forget that different tomato varieties are suited to different climates. If you’re in a hot part of the world, grow a heat-tolerant variety that is recommended for your region.

An added complication is humidity, or lack of it. Very high humidity can clog the pollen, so it’s unable to drop, while in very dry climates flowers may become so parched that pollen fails to stick and simply rolls straight off. In this instance regular watering may help to raise the humidity around the plants just enough to improve conditions.

Tomato fruits set and ripening

3. Not Enough Fertiliser (or the Wrong Type)

The final factor to consider is soil fertility. Are your tomato plants getting the nutrition they need to grow plump, tasty fruits? Even if you have rich soil, from the moment the first flowers appear you should be feeding your tomatoes with an organic fertiliser that’s high in potassium, or potash. Potash helps promote flower initiation, and hence fruit production.

Keep tomatoes fed with an off-the-shelf tomato fertiliser or make your own high-potash liquid fertiliser for free. Every garden should have a clump of comfrey for home-brewed fertiliser.

Once you’ve done all you can to improve conditions, you’ll just have to be patient and wait for Mother Nature to do the rest. Don’t lose heart because the situation is bound to improve. When it does, the tomatoes will come thick and fast, and then you’ll be wondering what to do with them all!

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Comments

 
"Insufficient Pollination Using an electric tooth brush generates very good vibrations for helping pollination of tomato flowers!"
Jacques on Friday 5 August 2016
"That's an inspired idea! Thanks for sharing Jacques."
Ben Vanheems on Friday 5 August 2016
"I knew about the bees buzz pollination, never thought about using an electric toothbrush to mimic this! That's it, going to use hubbies electric toothbrush and have a bumper harvest!! on a more serious level, this method will really help during these weeks of constant bad weather. "
Joyce Langan on Saturday 6 August 2016
"I touch flower to flower ,or cut one flower and touch 6-7 others ,plus I have lavender flover in my garden and bees come easy "
Kathy on Tuesday 9 August 2016
"I hand pollinate beginning with the first bloom of the season. No special tool needed, I have used sticks or fuzzy weed seed heads and rub the center of the flower, then proceed to the next flower. This method works well for me. I have a huge crop this year. Just hand pollinated again this morning "
Barbara Kuehl on Tuesday 9 August 2016
"Thanks Susan for taking time out of Ur busy schedule to post this for me-- I appreciate Ur thoughtful ways. I have used Q tips to pollinate container Jamaican Scotch Bonnet peppers-- will try that tomorrow at the TBC garden. " Every garden should have a clump of comfrey for home-brewed fertilizer" I copied this from the article. SO I am challenging U to bring comfrey plants to the Herb Plot for 2017 :)"
Ida Richards on Wednesday 10 August 2016
"Hi Kathy and Barbara. Thanks very much for your tips. You guys are definitely self pollinating pros!"
Ben Vanheems on Wednesday 10 August 2016
"I haven't seen a bumble bee for ages?"
Sandy Bowles on Saturday 13 August 2016
"Hi Sandy. Bee populations have declined in many regions. The best we can do is to plant lots of flowers to attract them and avoid using pesticides in the garden."
Ben Vanheems on Saturday 13 August 2016
"Hi My mom used a corn broom ,awesome tomatoes every year "
RON on Wednesday 24 August 2016
"Good stuff "
Ian rotherham on Monday 27 February 2017
"Can misting or providing partial shade lower temp enough to allow pollination during heat wave?"
Jack on Saturday 3 June 2017
"Hi Jack. It depends on how hot it is. If it's only slightly above optimal conditions for pollination, then shading and misting will certainly have the benefit of cooling the greenhouse and increasing the likelihood of successful pollination. But if it's excessively hot then even shading and misting may not lower the temperature enough. Essentially, give it a go as it will only improve conditions for your tomatoes."
Ben Vanheems on Monday 5 June 2017
"The electric toothbrush looks like a good idea but am surprised that no one mentioned using a tuning fork which has worked well for me. I use a 440Hz tuning fork as recommended by a friend but the usual that is recommended is middle C, I think but am not sure that is 258Hz."
Carol Ann on Friday 9 June 2017
"That's a brilliant tip Carol Ann, many thanks for sharing. I'd never have considered using a tuning fork - great idea!"
Ben Vanheems on Friday 9 June 2017
"For the electric toothbrush for pollinating, it's worth mentioning that it can be a cheap battery-powered kid's brush bought at a 'dollar store'. No need to spend what you would for a brand name that you would buy for yourself as recommended by a dentist."
Angus Campbell on Thursday 13 July 2017
"Very good point Angus, thanks for sharing. As you imply, no need for shiny, plaque-free teeth - just well-pollinated flowers!"
Ben Vanheems on Friday 14 July 2017
"Thank you for your help. Our problem is with 2 of our tomato plants out of the 12 we planted. Two of the plants are about 6 feet tall and have NO fruit on them, plenty of flowers that we "tickle" to pollinate. All our other ten tomato plants, bell pepper, Swiss Chard, zucchini, canteloupe and herbs are doing fantastic. We just cannot figure out why two of the tomato plants are ALL plant (huge and much taller than the others), with NO fruit? We have plenty of bees, we plant wild flowers and pots of flowers that attract the bees. Our plum trees are loaded with fruit also. Please help me understand what's going on, this isn't the first time this has happened. "
Cyndi on Wednesday 9 August 2017
"something to help encourage and attract pollinators .... plant flowers with your veggies and fruit, and try humming bird nectar feeders. bees love them! worked great for me."
kevin on Friday 20 July 2018
"Thanks for your tips Kevin - very useful indeed."
Ben Vanheems on Friday 20 July 2018
"I found this information on tomatoes more than helpful. Have been wondering why I always had so many blooms but no tomatoes now I know. Am so glad that I found exactly what the problem is. Will get me some tomato fertility tomorrow. I am having the same problem with my cantaloupe plants. They have grown so long and have bloomed like crazy but no cantaloupe. Will have to Google that as well. I can't thank you enough for all the information you have supplied me with. God Bless"
Linda Morgan on Wednesday 25 July 2018
" Hi Linda. You might like to try hand pollinating your melons. This simply involves removing the male flower (the one without the swelling behind it) then peeling back the petals, before gently brushing the stamens onto the top of the female flower. This is a great way of boosting the pollination efforts of any insects that may or may not be present. "
Ben Vanheems on Wednesday 25 July 2018
"My Better Boy has lots of fruit. But they are less than BB size and will not grow. It's been weeks. All new fruit does the same thing. I do not know what to do. Your help would be greatly appreciated!"
Beverly Goff on Sunday 5 August 2018
"I've been growing tomatoes for at least 15 years, and have never seen this happen before. I decided to purchase two 'heirloom' seedlings just to mix things up this year. One of the plants (a 'cherry' variety) has done very well and has been producing marvelously. The other, an 'Old German' has so far (it's now late August, in Vancouver) not produced a single tomato. Lots of flowers, and the plant is extremely healthy (green, bushy and over 5 feet tall) but no fruit. It sits outside in plenty of sun, with bees and wind aplenty. What gives?!?"
Scott on Friday 24 August 2018
"Hi Scott. That is a mystery, particularly as your other tomato is doing fine. The fact you are getting plenty of flowers implies it's healthy enough, but the lack of fruits is odd. If you have explored all of the options in the article then I'm genuinely stumped - sorry! It may yet fruit, given there's at least another month of summer where you are."
Ben Vanheems on Friday 24 August 2018
"My subwoofer rattles my whole car so how about using sound to vibrate the flowers."
marc on Wednesday 10 July 2019
"You could be on to something there Marc, for sure! Maybe this is the reason why some people play music to their plants."
Ben Vanheems on Thursday 11 July 2019
"They were all producing a lot of tomatoes but suddenly only my "Cherry 100" is still producing flowers and new fruit. The Rutger's is also producing a few flowers and fruit, but everything else stopped producing flowers, or all the flowers on my "Boxcar Wille" dropped off without fruiting. I did add 200 pounds of cow manure to the top of my soil a few weeks ago and didn't know the nitrogen was bad. It also has hit the high 80s and low 90s the past two weeks. Don't know which, although the plants have suddenly become a four foot tall jungle I can't even get through anymore so perhaps the nitrogen in the manure is the culprit. I added some bone meal two days ago to try to boost Phosphorus."
Steve on Friday 12 July 2019
"Hi Steve. It sounds like the sudden influx of manure has led to a rush of nitrogen, which has led to masses of leafy growth. Hopefully when that settles down the plants can be persuaded back to flower formation and fruit production."
Ben Vanheems on Monday 15 July 2019
"I have just watched your video on poor fruit set on tomato's. Here in Queensland, Australia we are going through a spell of high thirties to low forties temperature so I have decided that temperature is the problem. I would like to ask what sort of management is needed while mother nature runs her course? Should I maintain a regular soluble fertiliser application, should the plants be trimmed (they will be pretty tall in a months time), should the "spent" blossoms be pruned off?"
Ken Gray on Tuesday 31 December 2019
"You can ease off the fertiliser a little bit during the extreme heat. More fertiliser encourages more growth, which can be difficult to support/tiring in very hot weather. Trim plants as you normally would. There's no need to trim off the spent blossoms as they will naturally fall off anyhow. I hope temperature drop for you soon. It is shocking to see all the wildfires in NSW and Vic on the news over here in the UK. My thoughts are with you guys."
Ben Vanheems on Thursday 2 January 2020
"I have lots of flowers and after reading this I went out with a small brush (no electric toothbrush) and lightly brushed all the flowers and fed the plants a little tomato fertilizer. But as I did this I noticed quite a few flowers that were falling off with a dying stem. What causes this? "
topmoo on Tuesday 21 April 2020
"If the flowers are falling off it sounds like those ones weren't successfully pollinated so have simply shrivelled up and dropped off. This happens with flowers that don't set fruit. Make sure pollinators such as bees can get to the flowers. If the tomatoes are in a greenhouse or polytunnel/hoop house - open up all of the doors and vents so they can get in. As well as tickling flowers with a brush, simply twanging or tapping supports, or likely shaking the plants themselves, may be enough to dislodge pollen so flowers are successfully pollinated."
Ben Vanheems on Thursday 23 April 2020
"It has been 106 and a 103 in central California. My tomato plants are huge and have many flowers but don’t produce. I fertilized and water carefully and still no luck especially with my cherry tomato’s. What do I do?"
Laura couch on Monday 13 July 2020
"Hi Laura. Try tapping the plants to help dislodge the pollen so they can set fruit. Other than that it may be a question of hoping for cooler weather, so the tomatoes are better able to set fruit. It seems you're doing all the right things already."
Ben Vanheems on Tuesday 14 July 2020
"I don't usually post on forums but after reading all the comments, here goes, All the above suggestions will work however(unless I've missed it) I'm surprised that no one has mentioned the following. A simple solution (if you are able) is to cut a blossoming stem and use it to touch the other blossom. I know this could be tedious for some with lots of tomato plants or flowers, but the result is that your plants will be pollinated and should all other conditions be good, you should begin seeing fruit in a short while. Remember to be patient as fruit will begin to appear once blossoms wither. "
O'Neill Dunlap on Monday 20 July 2020
"That's a great tip there thanks. As you say, it can take a little time but interactions like this will certainly help to boost pollination."
Ben Vanheems on Wednesday 22 July 2020
"From Ireland : after a pretty miserable summer, my tomato plants had a few flowers which never progressed into fruit. Maybe I showed them a bit late. Do I throw out these plants and start afresh next summer. Many thanks, Maggie O Neill"
Maggie on Saturday 19 September 2020
"Hi Maggie. Yes, unfortunately the best course of action would be to start afresh next spring. I don't know if you're thrown your current tomato plants or not, but there may still be a few weeks for any green fruits to ripen. Next spring, start nice and early and choose a variety suitable for outdoor growing (even if you intend to grow it in a greenhouse) as it will be more vigorous and likely to produce fruits in time."
Ben Vanheems on Monday 21 September 2020
"My tomato plants are healthy as shown by the healthy leaves. But each plant has only 2 or three big, delicious fruits, though the flowers are plenty. I see most of the flowers drying without producing the fruit. Am considering using electric toothbrush to mimic bees buzzzz. Question, How close should the tooth brush be ? Am afraid the flowers will fall off if the toothbrush touches the flowers. thank you for considering this question."
weng R. Prieto on Sunday 14 February 2021
"Hi Weng. Tapping the stems and plant supports is one way of helping pollination along - to mimic the buzz pollination of a bumblebee. You could try an electric toothbrush. I'd rest it on the stem leading to the flower, observing the flowers closely to see if they vibrate. If it's too strong, you could move further down the stem, away from the flower, until you get a gentle vibration that isn't too strong."
Ben Vanheems on Monday 15 February 2021
"just a thought could I use my wifes vibrator instead of an electric toothbrush?"
Mark Dale on Saturday 10 July 2021
"Hi Mark. I think that could be highly effective!"
Ben Vanheems on Monday 12 July 2021
"I live in Darwin and its supposed to be the dry season but it is extremely humid for this time of year.. My Tomato plants have been a miserable failure for 2 years. Some sort of wilt, not setting fruit on 5 ft tomato plants. Growing in large tubs out in the open and above ground bed. Decided to give it away for a couple of years to rest the soil. Grew about 50 seedlings this year and only about 10 survived. One half fruited, then got wilt while the other 5 have lots growth but no fruit set. Cheaper and less frustrating to buy Supermarket version"
Kate on Sunday 1 August 2021
"That is frustrating Kate - what a shame. I hope other crops have behaved themselves for you at least."
Ben Vanheems on Monday 2 August 2021
"Just want to thank all of you for the comments and suggestions here, and thanks Ben for the article! I have had a terrific crop of cherry tomatoes and early girls; but my heirlooms aren’t producing well. A lot of flowers dry up, and have one heirloom plant that hasn’t set even one fruit. I’ve watched carefully and it’s flowered maybe 10 times in the last month but nothing else. I just tried my electric toothbrush so we’ll see! Thanks again to all!"
Barb S. on Thursday 16 September 2021
"Sorry to here that Barb. Certainly the electric toothbrush trick does seem to bear fruit (literally!). It's something I'll be doing more of next season for sure. Hopefully your heirlooms will come good soon."
Ben Vanheems on Monday 20 September 2021
"I use my vibrator (massage) with a small cotton ball taped onit- big crops"
Lisa on Wednesday 26 January 2022
"Used to grow commercially in the desert in Israel. Use a back sprayer and spray a soft spray of water on the flowers. Also there is something called Tomo set that helps set more flowers. Tomato set."
Selwyn Cainer on Tuesday 24 May 2022
"Hi Selwyn. Thanks for sharing that. I guess the extra humidity from the spraying of water helps counter the very dry air. Both dry air and very, very humid air can hamper pollination."
Ben Vanheems on Friday 27 May 2022
"Would it help to thin the leaves in the lower sections of the plant so that breeze and bees might get to the flowers early? Im in Central Texas with pretty plants and little fruit so far"
Gary on Tuesday 23 May 2023
"Hi Gary. Yes, it's often recommended to remove all of the leaves below the lowest truss once the plants are fairly established. This helps with airflow etc - and might possibly help with pollination too."
Ben Vanheems on Tuesday 23 May 2023
"My plants just haven’t grown. Only a few flowers on one or two plants, none on the rest. 3 green toms on one other but not ripened. It’s been over 6 weeks since they were planted out. It’s like they just stopped growing. They’re different varieties, in different places (inside and out), all in pots. Good peat free compost and manure. Watered properly. Cool/cold spring delayed planting out and after one week of warm weather, and a dry spell at start of June, it’s now a v cool and VERY wet July! Can’t be rain though as it’s same in little greenhouse! It’s both heartening AND depressing that others have had the same problem."
Karen Roscoe on Saturday 22 July 2023
"Hi Karen. So sorry to hear this. If it's any consolation my outdoor tomatoes have already got hit by blight - and just as they were getting into their stride! This summer certainly seems to be bringing its challenges. Hopefully your tomatoes will pick up soon. :-)"
Ben Vanheems on Tuesday 25 July 2023

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