5 Ways To Fix Tomato Flowers Not Setting Fruit

Are you getting plenty of flowers on your tomato vines but no fruits? You’re not alone – many tomato growers have the same complaint. It is understandably heartbreaking to see your tomato plants flowing but not producing any tomatoes after all those months of care and love you have given to the crop. If your tomato flowers are blooming but not setting fruit don’t worry the fix isn’t too tricky most of the time. Once you catch the root cause and make the necessary fix, you can get your tomato plant to producing those ripe, juicy vegetables you have been craving for so long.

tomato flowers not setting fruit
Tomato Flowers Not Setting Fruit

If your plants are blooming but not setting fruit, one of the following could be blamed:

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1. Tomato Flowers Not Setting Fruit Due To Inadequate Pollination

Most plants rely on birds, bees, butterflies, and insects to help them pollinate and set fruit. Tomatoes are self-pollinating plants. Each plant has both male and female parts. Male parts drop pollen grains on the female parts to fertilize and set fruit on them. If your tomato flowers are blooming but not setting fruit it could be down to inadequate pollination.

However, self-fertilization isn’t always enough to produce the expected harvest. The presence of pollinators, like bees, give plants the little push they need (literally), to break free the pollens and drop it down on the stigma, which is the female part. 

Lets look at ways to fix inadequate pollination:

Wait for suitable weather

Often, bees won’t participate too actively in cold, wet, or windy weather. Let the unsuitable weather pass, and hopefully, the bees will return to work. Your tomato plants will be able to set fruit.

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Improve Access For Pollinators 

If you’re growing tomatoes in a greenhouse, it’s possible that beneficial insects can’t find their way to the plants. Open up the doors and vents to let bees and insects in the place to do their job.

Give Them A Jerk

Artificial pollinating the plants by hand is often a great idea to get things going again. Give the flowers a little jerk or gentle flick with your fingers, just enough to release the pollens. Be careful not to harm the delicate blooms in the process. Once you’ve done your part, just sit back and wait for nature to handle it from here. 

See also  Do Tomatoes Need To Be Pollinated

2.Tomato Flowers Not Setting Fruit Due To High Temperatures

Another reason for your tomato flowers not setting fruit might be due to temperature. Tomato plants flourish between 65° to 70°F. Tomato plants love warmth, but too much heat can be a problem. Pollination will slow down in hot spells since the excess heat can make the pollens infertile. Infertile pollens won’t fertilize the stamens, and the plants won’t set fruit. 

Here are some things you can do to help:

Choose The Correct Variety

Not every variety will be well-suited to your region. Get seeds from a local garden center and choose the ones that are well-adapted to your climate. If temperatures are expected to rise too high in your area, select heat-tolerant varieties to plant.

Water Them Well

While you wait for the hot temperatures to subside, keep the plants well-watered and nourished. If the plants are healthy enough, they’ll start producing again once the temperatures return to the suitable range. 

Check Greenhouse Ventilation

If like me you grow your tomatoes in a greenhouse check that the ventilation is working. During a heatwave, I didn’t realize the automatic window opener was stuck so its worth double checking windows and ventilation. If you have really hot nights consider leaving the door open slightly to help bring the heat down.

3. Tomato Flowers Not Setting Fruit Because Of Unsuitable Humidity

Both high humidity and low humidity can prevent tomato plants from setting fruit. Too much moisture can bind the pollens together, preventing them from dropping freely onto the stigma. On the other hand, too little humidity will make the pollens too dry to settle on the stigma. Instead of staying to fertilize the stigma, they will roll right off, which again prevents the tomato flower setting fruit. In both these cases, the harvest will suffer.

Lets look at ways you can fix these two extremes.

Water Well In Case Of Little Humidity

If the humidity is low, water the plants thoroughly to make up for some of the moisture lacking in the air around the plants.

See also  What are The Best Tomatoes for Canning

Artificial Pollination In Case Of High Humidity

If the tomato plants are in a high humidity climate, you can intervene by giving a little tap to the flowers. It will help to get the pollens to where they need to be. 

4.Tomato Flowers Not Setting Fruit Due To Insufficient Air Circulation

Since tomatoes are self-pollinating plants, they rely on air to move pollen from the male parts to the female parts. Lack of ample air circulation will affect the plants’ ability to fertilize. One of the common causes of tomato flowers not setting fruit is air circulation. Plants growing too close to one another or spreading horizontally over the garden bed won’t allow enough airflow to the flowers.

Plant Smartly

  • Choose an open site where the airflow to your plants won’t be obstructed.
  • Allow enough space between individual plants for each one to breathe freely. Plant determinate varieties 12 to 24 inches apart and indeterminate varieties 36 to 48 inches apart. 
  • Install support for your plants to grow vertically. Vertically growing vines allow foliage and flowers to easily access air from all sides compared to horizontally growing ones.

When it comes to supporting tomatoes, string and twine are no good. I stopped using string when I found my tomato plants collapsed on more than one occasion. I use both wire and clips to support my tomatoes. both are re-usable year on year.

Control Horizontal Growth  

Too many branches can also hinder the air supply to the plants. Don’t let your plants grow too bushy, or they’ll not be able to pollinate effectively. Pinch out the suckers as they sprout, so the plant focuses its energies on the flowers and fruits and allows air circulation.

5.Incorrect Or Inadequate Fertilization

The plants won’t produce those juicy, plump tomatoes out of nothing! They’ll need plenty of nutrients from the soil for an abundant harvest. Planting in rich, fertile soil is vital, but not enough. Tomatoes are heavy feeders, and they’ll soon use up all the nutrients that came from the compost you prepared the soil with before planting. If your tomato flowers not setting fruit fertilization is required throughout the growing season to keep the crop healthy. Not using any fertilizers, or failing to choose the correct fertilizer can be the cause of your fruitless tomato plants.

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High-potassium Fertilizers

Once they set the first set of flowers, the plants will need an extra boost to keep up the production. They’ll need potassium-rich fertilizers at this stage to set fruit on the flowers. Use a high-potash fertilizer that has especially been formulated for tomatoes. 

Low Nitrogen

Remember not to feed it nitrogen, especially if your concern is fruiting. High-nitrogen fertilizers will promote green growth, but you’ll find little flowering and fruiting on the plants.  

For the best tomato feed, you need both high potassium and low nitrogen. Look for specialist feeds such as Miracle-Gro as it has the right balance of nutrients specifically formulated for tomatoes.

Conclusion

Whatever may be the cause of unsatisfying results from your tomato crop, don’t give up just yet! There can be so many reasons for tomato flower blooms but no tomatoes and just as many fixes. Finding and addressing the issue might be a little frustrating, but once you’re rewarded with the plentiful, juicy tomatoes, it will all be worth it!

4 thoughts on “5 Ways To Fix Tomato Flowers Not Setting Fruit”

  1. I think I have a heat problem. It’s been in the low to mid 90’s (h) to mid-40, low-50 (n), for the last few weeks with only a slight break. I have some tomatoes setting fruit such as my San Marzanos, Amish Paste and my SunGold. I have a few Mortgage Lifters producing, but the rest aren’t. I have mostly Mortgage Lifters, Chef’s Choice and paste-types.

    I use drip watering on a digital timer so they get a routine watering (4x day @ 15 minute cycle, 2gph emitter, sandy-loam soil). Most of my tomatoes are in 5-gallon buckets and some in my rear garden are in-ground. The only difference between the two is the bucket tomatoes have curly leaves on their tops and the in-ground do not. Although unsightly, the curling doesn’t seem to be bothering the plants, but I’m no expert! I think this is another sign of too much heat, but why aren’t the in-ground tomatoes doing the same curling? Maybe because the roots are above ground in buckets? The in-ground have the Earth to cool them. At least this is my theory.

    This year I changed out all my dirt in the buckets for a custom pre-mix I got from the local nursery. The only thing I added was slightly aged rabbit manure (I’d guess less than 6 months from the butt…lol). My tomato plants are huge already and growing better than they ever have. It’s been about a month since I moved the plants outside and some already have at least 5/8″ diameter stalks or larger, and a few over 7 ft. tall. Just not much fruit yet. The majority has no fruit at all which has me concerned since my area has a short growing season (zone 6a). Our weather is very unpredictable. For now it’s been HOT HOT HOT… almost uncommonly hot. Nighttime temps are slightly above average.

    I haven’t given the plants any extra fertilizer yet. I generally don’t do that until fruit sets – that and I have rabbit poo in there already. Obviously I don’t want to give them too much and end up with a nice plant with no fruit.
    Years ago I’ve used rabbit poo when I lived in a different zone and had fantastic results, so I think I can rule that out. I also have evidence of my cucumbers getting too hot. They are dropping flowers and aren’t producing as well as they should. I’ve been able tot pick a half-dozen cukes so far.

    So is my main issue heat? Should I give them some Miracle-Gro or? Again, I don’t want to over-do the fertilizer.

    Maybe I’m just being impatient since I’ve already been picking a few Sungold tomatoes. I realize not all tomatoes produce at the same rate, but as healthy as the plants are – you’d think I’d start seeing more green tomatoes at least.

    I’m also trying to figure out a way to shade or cool them. I thought about adding some misting emitters on my drip line (above the plants) to cool the air around them during the heat of the day, but I worry about fungus, mold, BER, etc.
    Maybe i can use a tarp or something to shade them? I haven’t had to do that before. Any ideas?

    Thank you!

    Reply
    • Thanks for writing in! the hot dry weather has caused lots of problems especially for tomato plants. Reading through I think the issue is that the plants in the ground are able to suck up the mosture over a larger area whereas the tomatoes in buckets have limited area and are more than likely drying out much faster. This year I dug holes for some of my bucketed tomatoes and they are doing much better. I am also soaking them once every few days as drip feeding dosent always appear to be enough. Dont worry my plants are also curling and they seem to be fine.

      I have had lots of problems with manure over the last few years. It really needs to be rotted down over a period of at least a year or 6 months for kitchen compost. You are absolutely right dont start feeding until the fruit starts to set otherwise you will get exponential growth and no fruit. I think your issue is heat. What I have found has helped this year especially mine that are growing in a greenhouse is to drench the floor area as well as the plants this increases the humidity and cools the greenhouse down. Best of luck and I look forwards to seeing some photos I can publish on the site.

      Reply

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