4 Reasons Why Your Tomatoes Aren't Fruiting

Are your tomatoes not fruiting? Check out our helpful guide on ways to combat this common issue when growing your own tomatoes.

Why Aren't My Tomato Plants Producing Fruit?

You chose your tomato seedlings carefully. You planted them. You waited for those first beautiful flowers—and waited. Eventually you found yourself googling some version of, "tomato plant growing but no flowers" and landed here.

While gardening can be incredibly rewarding, it can also feel frustrating when something doesn't grow as intended. Take a deep breath, and know we have some simple fixes to help improve the health of your tomatoes.

Whether you're dealing with determinate or indeterminate tomatoes, it's not unusual to have a tomato plant not flowering. We'll break down four reasons your tomatoes might not be fruiting so you can learn how to increase flowering in tomatoes. With a few small changes to their growing environment, you could have flourishing tomatoes soon.

1. Insufficient Pollination

Your tomatoes might have trouble flowering if they’re not pollinating enough. While tomatoes are self-fertile—meaning, the flowers can pollinate themselves—bees can help improve pollination.

When a bee nudges a flower, it can dislodge the pollen from the stems. So if you’re growing tomatoes inside, your plant might have trouble pollinating without a visiting bee to help shake things loose.

To help your tomato plants pollinate indoors, you could try:

  • Moving your plant outside – If it’s an appropriate time of year for tomatoes, you can try taking your tomato plants outside to expose them to bees and other insects who might help dislodge their pollen. If you’re using an AeroGarden, all you’ll need to do is move the bowl. Simply unplug the pump, take the bowl off of the base and move it outside!
  • Bringing “outside” in – Alternatively, you can try moving your tomato plant close to an open, screen-less window, so that bees can find it. (This does run the risk of allowing more insects into your home, so take that into consideration when deciding on your preferred pollination boosting methods.)
  • Gently shaking your plant – If you don’t want to expose your plants to bees, you can mimic those buzzing vibrations by gently shaking your tomato plant. You can also utilize our Be the Bee Pollinator to pollinate more effectively.

This is a common challenge for tomato gardeners growing their plants indoors, so don’t feel discouraged. Your plant could be pollinating again soon with a little help from you.

2. High Heat Levels

If you’re sweating through a heat wave, that same heat could affect your plant’s ability to effectively produce pollen. Most tomatoes need a daytime temperature that stays below 87 degrees Fahrenheit, and nighttime temperature that falls below 76 degrees Fahrenheit if they’re going to pollinate and produce fruit.

Fortunately, if you keep your tomato plant healthy and watered throughout the heat weave, it should start flowering and eventually fruiting tomatoes once the temperature calms down.

Here’s how to take care of your tomatoes during a heat wave:

  • Keep outdoor plants watered, and—if possible—move them to a shady area
  • If you have central air conditioning, consider moving potted tomato plants inside
  • If your plants already live inside, consider moving them to a cooler area of your home
  • If you live in an area where heat waves are frequent, shifting to indoor gardening options like hydroponic gardening can help provide a stable environment for m

3. Insufficient Light

If you’re wondering how to increase flowering in tomatoes, try increasing how much light they receive. Tomatoes need eight hours of daylight to flower. Sunlight gives your tomato plants the energy to produce fruit, so if your plant doesn’t have enough sunlight, you’re less likely to see tomatoes fruiting.

To increase sunlight, try:

  • Moving your potted plant – If you have a potted tomato plant, try moving it to a sunnier location.
  • Moving any items shading your plants – If you can’t move your tomato plants, see if there are any items currently shading your plants that you can move.
  • Adding a grow light – If you’re growing your plant inside, consider adding a grow light. These can help give your tomato the energy it needs to flower. If you already use a grow light, consider leaving it on longer throughout the day.

While tomato plants need sunlight (or a grow light) to flower and fruit, tomatoes don’t actually need sunlight to ripen. In fact, once the plant has fully grown its tomatoes, those tomatoes will ripen fastest in the shade and at night.

4. Fertilizer and Nutrient Issues

Those growing tomatoes using hydroponic gardening can help give their plants a nutrient boost by using plant food in 3 oz. or 1 liter sizes. If you’re using plant food designed for hydroponic gardening for the first time, we recommend the Easy Feed Plant Food (Nutrients) Dispensers.

Here’s why we love dispensers:

  • The syringes make it easy to give your plant the right amount of nutrients.
  • It dispenses easily into your garden.
  • It works well with all hydroponic garden models.

If you have any questions about when to use plant food—and how much to use—follow the instructions on the packaging, or reach out to the customer service team with more detailed questions.

Tips to Help Your Tomatoes Flourish

You should see yellow flowers on your tomato plants at 5–7 weeks, and soon after that, you should see some of those flowers turning into little green tomatoes. If you don't get flowers, you will never get fruit! Sometimes, healthy tomato plants don't seem to want to flower, but very often you can turn them around by changing their environment:

  • Make sure the Light Hood/Grow Lights are just an inch or two above the tops of the plants.
  • Give the plants more hours of light by selecting "Herbs/Basil" in the Plant Selection setting of your Advanced AeroGarden for 7-10 days, and see if flowers start to form. With the Ultra model AeroGarden, use Custom Setting to change the light cycle timer.
  • Do a rinse and refill to restore a good nutrient balance.
  • Make sure that the plants have been pruned to open up light to the entire plant.
  • Ideal daytime temperature for tomatoes is 70–76 degrees; ideal nighttime temperature is 65–72 degrees. Tomatoes like nights to be cooler than days; growing in a constant temperature environment such as is found in many homes can inhibit blooming.
  • Flowering and fruiting plants often require stress to produce flowers and fruit. Stress the tomato plants by skipping a feeding for a week, and/or unplug the AeroGarden and then put it in a closet for a day or two. This changes the conditions that the plants have become accustomed to, and can stimulate them to flower.
  • If you have done a lot of pruning, stop for a couple of weeks.
  • If you have not pruned very much at all, then now is the time—plants should be just an inch or two below the grow light hood and should be growing within the footprint of the AeroGarden. Prune as much as 1/3 of the plant at once to create a dense and compact shape.
  • Spray the plants with Blossom Set (or a comparable brand), a hormone that encourages bloom and fruit in tomato and pepper plants. It's available in nurseries and garden centers; a small pump bottle should last you a long time.
  • Move the AeroGarden to a different room to change conditions, which can stimulate flower production.

Tomato FAQs

Tomatoes can be a little finicky! Outdoors, they may not set fruit if days are too hot or too cool, if nights are too warm or too cool, if the soil is too wet or too dry, and so on. If your tomatoes are blooming, then you are on the right track, and hopefully some of the ideas here will start those tomatoes coming:

  • For fruit to set, the pollen in the flower has to be shaken loose and then land on another part of the flower. Outdoors, wind and bees do the shaking; indoors, you have to do it (be the bee!) If you have been gently shaking the plants as recommended but are still not seeing fruit, try pointing an oscillating fan at the AeroGarden, or touch our Be the Bee Pollinator for a fraction of a second to the stem directly above the flowers.
  • Purchase a little pump bottle of Blossom Set or comparable product from your local nursery. It’s a hormone that encourages fruit set. Use as directed.
  • Is your room too warm, or too cool? The ideal range for fruit set is 70 to 76 degrees. Is your AeroGarden in a sunny window? That’s too hot.
  • Are there lots of flowers? That limits fruit-set. Try removing some.

If your tomato plants have lots of fruit that isn't ripening, it may be that the plant doesn't have the energy to "feed" all of them. Imagine a mother cat trying to feed a litter of twenty-five kittens! If your plants are loaded with green tomatoes, consider removing some to let the rest get more of the mother plant’s energy.

Tomatoes are a summer-time crop; the fruit needs warmth to ripen. If the ambient daytime temperature of the AeroGarden is under 70 degrees, you need to find a warmer place for it, or use a space heater (but avoid radiant heat!) to bring the temperature up.

Tomatoes grown in the AeroGarden should be pruned early and often in order for them to grow full and bushy, as well as to flower prolifically. If tomatoes are not pruned early enough in their growth, they will grow tall with lots of leaves and flowers at the top, but no growth on the lower stems.

Once this has happened, it will take some patience to train your tomatoes to leaf out again at the base. Prune off about a third of the leaves (and flowers, if any are present) at the top of the plant, removing the newest, smallest leaves.

This will stimulate the plant to branch out lower on the stem, and eventually to produce flowers and fruit throughout its height. You will need to continue to prune the top of the plank here to see a detailed article with a slideshow on how to prune plants that have grown up into the lights.

Click here to see a detailed article with a slideshow on how to prune plants that have grown up into the lights.