7 Reasons Why Your Tomato Plant Is Not Flowering & How to Fix It - The Scientific Gardener (2024)

In this article, let us look at different causes for flowering issues in tomato plants and the tips to solve the problem.

I have poured in hours of research on how the other experts have tackled the flowering issues. I have also incorporated my personal experience in treating this condition.

Let us keep the ball rolling!

Why Is My Tomatoes Plants Not Flowering?

Several nutritional and environmental factors may cause healthy tomato plants not to flower. It may further affect the fruit yield. It is frustrating to have big and luscious tomato plants but no flowers. Flowering is the crucial stage in the life of tomato plants. If there is no flowering, the chances of seeing juicy tomato fruits are minimal.

The different stressors faced by the tomato plants that affect flowering are discussed below.

1. Inadequate Sunlight

Tomato plants need 6-8 hours of sunlight for optimal growth and flowering. If they do not receive direct sunlight for long hours, they may not flower.

Tomato plants require warm weather and long hours of sunlight (about 6-8 hours). If the plant is not getting enough sunlight, it may stop producing flowers.

Also, if there is exposure to an extended period of light, then the flowering may still be affected.

2. Damage by insects or disease

Sometimes, tomato plants are susceptible to several diseases and pests. It may disturb the capability of the tomato plants to produce flowers.

Tomato plants may be easy to grow. But, they are also prone to several diseases and attacks by pests.

I have noticed that certain fungal diseases, including botrytis, heavy bacterial spot, bacterial speck pressure may affect the flowering of tomato plants. So, the affected plants may not produce fruits.

See Also

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3. Over Fertilization

The tomato plants may not produce enough flowers if there is an excess of nitrogen in the soil. However, it may stimulate the growth of foliage.

Tomatoes require nitrogen, phosphorus, and potassium for their growth. But, both high or low nitrogen levels in the soil may affect the flowering.

High levels of nitrogen fertilizer may encourage vegetative growth in the early stages. But, it may inhibit the production of flowers and pollination causing low fruit yield.

In contrast, low nitrogen may cause spindly vines. It may not be sufficient to support the growth of tomato plants.

4. Watering Issues

Another factor that affects the flowering of tomato plants is the lack of nutrients due to shallow watering. But overwatering may also be a problem.

The tomato plants have deeper roots that may reach about 5 feet. It requires about 1 to 1½ inches of water every week to yield more fruits.

If there is shallow watering, it may cause stress on the plants due to low soil moisture. It may affect the flowering of tomato plants. But, don’t let them get flooded.

5. High Temperature And Humidity

The exposure of the tomato plants to high temperatures for a long time may cause little flowering. It may be because the plant spends its energy on survival than flowering.

Tomatoes grow well in the temperature range of 70F-85F. But, a high daytime temperature over 90oF may cause no flowering.

It may tolerate extreme temperatures for short periods. After that, the plants attempt to save energy to survive rather than flowering.

The same thing happens during cold temperatures. The low nighttime temperatures may affect the flowering as the pollen becomes non-viable. Therefore, poor pollination may cause drying and falling of blossoms.

The preferred humidity for tomato plants is 40-70%. If there is fluctuating humidity, it may interfere with the pollination and affect the flowering.

6. Different tomato varieties

Not all tomato varieties produce more flowers. The determinate variety produces flowers only once whereas the indeterminate variety will continue to flower throughout the season.

I observed that not all tomato plants produce the same amount of fruits. Some varieties are heavy producers whereas some are not.

For example, heirloom production yield is lower than a hybrid.

There are determinate and indeterminate varieties.

Determinate varieties grow to a determined height and will stop producing fruiting after once. Indeterminate varieties may keep producing fruits until the first frost.

7. Pollination Problems

Sometimes tomato plants may produce enough flowers but they fall off without producing fruits due to lack of pollination. The condition is called blossom drop.

Tomatoes rely on airflow, wind, and bees to pollinate and produce fruits.

There is another scenario where the tomato plants produce flowers but they may fall off and yield no fruits. The tomato plants may face nutritional or environmental stress-causing problems.

The condition when the flower stem turns yellow and flowers fall off is called blossom drop. There will be interference in pollination and fertilization.

You may check this video on why the tomato plants are not flowering:

How To Increase Flowers On Tomato Plants?

If your tomato plants are not flowering, you may water regularly, provide appropriate fertilizer, give adequate sunlight, and practice good disease control measures. You may choose an indeterminate variety for more flowers.

Most of the time, you may rectify the flowering problems of the tomato plants following certain tips.

Plant indeterminate tomato plants

Choose tomato plant varieties that grow well in your area. Also, ensure that there is pollination. Plant indeterminate tomato plants as they keep flowering for several months.

Water the tomato plants regularly

Grow tomato plants in well-drained soil and water regularly to grow well in tough daytime temperatures.

Also, take care to keep the root zone moist throughout the growing season. It will reduce the stress on tomato plants and encourage flowering.

Provide adequate sunlight and circulation

Allow good circulation of air by spacing the tomato plants enough apart. You may also use a stake or cage around the plants so that they don’t grow into each other.

Choose a spot where there is adequate sunlight throughout the day. Do not plant near the buildings and trees.

Use the right amount of fertilizer

A balanced fertilizer regime is required for the proper flowering of tomato plants. It should have adequate nitrogen, potassium, and phosphorus for good fruit yield.

The University of Missouri recommends a fertilizer that is low in nitrogen but high in phosphorus and potassium for increasing flowering in tomatoes.

I prefer to use a fertilizer of nitrogen, phosphorus, and potassium in the ratio of 5-10-10 along with the trace minerals.

Practice disease and pest control protocol

Follow appropriate insect control measures.

You may check your foliage for wilt, spots, or lesions. If you notice any symptoms of disease, then tackle it immediately to prevent the spread of infection.

You may have to destroy the plant if the disease can not be cured.

Here is the video to prevent the blossom drop problem:

FAQs

Summary

In conclusion, I hope that this article has given you a few tips on improving the flowering of tomato plants.

If you have any experience in treating tomato flowering problems, let me know in the comment box. Also, you may contact me for any queries.

Do pass on the article to your friends and family!