Tomatoes are among the most popular and rewarding crops for your home garden. They are versatile, delicious, and nutritious. But what if your tomato plants are not flowering? What if you have healthy green foliage but no signs of yellow flowers or red fruits?

It’s frustrating and disappointing for gardeners when their tomatoes don’t grow well after putting in time and effort. No need to worry. There are many reasons why your tomato plants aren’t flowering, but most can be fixed with simple changes.

In this blog post, we will explore the common causes of tomato plants not flowering and how to increase flowering and fruiting in your tomatoes. We will also share some tips and tricks to help you grow the best tomatoes possible. Let’s get started!

Healthy green foliage, but no signs of flowers.

1. Temperature

Temperature is one of the most important factors affecting tomato flowering and fruiting. Tomatoes are warm-season crops that thrive in temperatures between 70°F and 85°F (21°C and 29°C). If the temperature is too low or too high, your tomato plants may not produce flowers or fruits.

• Low temperature: If the nighttime temperature drops below 55°F (13°C), your tomato plants may stop flowering or drop their flowers. This is because the cold temperature affects the development and pollination of the flowers. Low temperatures can also slow down the growth and metabolism of your plants, making them less productive.
• High temperature: If the daytime temperature exceeds 95°F (35°C), your tomato plants may stop or drop their flowers. This is because the high temperature causes the pollen to become sterile or clump together, preventing fertilization. High temperatures can also stress your plants and reduce their photosynthesis, making them less healthy. You can read our expert tips on heat stress management.

To fix this problem, you need to monitor the temperature in your garden and provide some protection for your tomato plants. 

• You can use a thermometer or a weather app to check the temperature regularly.
• You can also use a frost cloth, a row cover, or a greenhouse to protect your plants from cold snaps or frost.
• You can also use a shade cloth, a trellis, or a patio umbrella to protect your plants from heat waves or scorching sun.

2. Light

Another crucial factor that affects tomato flowering and fruiting is light. Tomatoes are sun-loving plants that need at least 6 to 8 hours of direct sunlight daily to produce flowers and fruits. If your tomato plants lack light, they may not flower or fruit.

Sunny garden with healthy tomato plants.

• Shade: If your tomato plants are growing in a shady spot, under a tree, or next to a tall building, they may need more sunlight to flower or fruit. Shade can also reduce the temperature and air circulation around your plants, making them more prone to diseases and pests.
• Clouds: If your tomato plants grow in a cloudy or rainy season, they may also not receive enough sunlight to flower or fruit. Clouds can make plants more prone to infections by lowering temperature and increasing humidity.

To fix this problem, you must ensure that your tomato plants get enough light.

• You can choose a sunny spot in your garden, away from any sources of shade.

Reflecting sunlight onto tomato plants.

• You can also use a south-facing wall, a fence, or a trellis to reflect more light onto your plants.
• You can also use grow lights, significantly if you are growing your tomatoes indoors or in a greenhouse.

Artificial Grow lights illuminate tomato plants indoors.

3. Nutrition

A third vital factor that affects tomato flowering and fruiting is nutrition. Tomatoes are heavy feeders that need a balanced and regular supply of nutrients to produce flowers and fruits. If your tomato plants are not getting enough nutrients or getting too many nutrients, they may not flower or fruit.

• Nitrogen deficiency: If your tomato plants do not have enough nitrogen, they may have yellow or pale green leaves. They may also have stunted growth and struggle to produce flowers and fruits. Nitrogen is essential for forming chlorophyll, which is responsible for your plants’ green color and photosynthesis. Nitrogen also helps plants produce proteins, enzymes, and amino acids, which are vital for their growth and development.
• Nitrogen excess: If your tomato plants have excessive nitrogen, they may exhibit dark green or purple leaves. Additionally, they may have an abundance of leaves but a scarcity of flowers and fruits. Too much nitrogen makes plants grow more leaves and stems instead of flowers and fruits. Too much nitrogen can attract pests and diseases, and make your fruits taste and quality worse.

To fix this problem, you need to provide your tomato plants with the right amount and type of fertilizer. You can use a balanced fertilizer, such as 10-10-10 or 20-20-20, that contains equal amounts of nitrogen, phosphorus, and potassium. You can use a special fertilizer for tomatoes that has more phosphorus and potassium than nitrogen, like 5-10-10 or 8-32-16. Phosphorus and potassium are important for flower and fruit formation and quality.

• You can apply fertilizer to your tomato plants according to the label instructions, usually once every two weeks or once a month. Please don’t over-fertilize your tomato plants.
• You can also use organic fertilizers, such as compost, manure, or worm castings, to enrich your soil and provide your plants with more nutrients and beneficial microorganisms.
• You can also use foliar sprays, such as fish emulsion, seaweed extract, or compost tea, to boost your plants’ nutrition and health.

4. Water

A fourth critical factor that affects tomato flowering and fruiting is water. Tomatoes are thirsty plants that need a consistent and adequate amount of water to produce flowers and fruits. If your tomato plants are not getting enough or getting too much water, they may not flower or fruit.

• Drought: If your tomato plants are not getting enough water, they may wilt, droop, curl, or turn brown. Drought can stress your plants and reduce their photosynthesis, growth, and yield. Drought can also cause blossom end rot, a common disorder that causes the bottom of your fruits to turn black and rot.
• Flood: If your tomato plants are getting too much water, they may also wilt, droop, curl, or turn yellow. Flood can also stress your plants and reduce their oxygen, drainage, and nutrient uptake. Floods can also cause root rot, a fatal disease that causes the roots of your plants to decay and die.

To fix this problem, you need to water your tomato plants properly and regularly.

• Use a rain gauge, a moisture meter, or a finger to check the soil moisture around your plants.
• You can also use a drip irrigation system, a soaker hose, or a watering can to water your plants at the base, avoiding the leaves and stems.
• You can also use mulch, such as straw, wood chips, or grass clippings, to cover the soil, conserve moisture, prevent weeds, and moderate temperature.
• You should water your tomato plants profoundly and infrequently rather than shallowly and frequently. It would help if you watered your plants when the top 1 to 2 inches (2.5 to 5 cm) of soil feels dry to the touch, usually once or twice a week.
• You should water your plants early in the morning or late in the evening, avoiding the hottest part of the day. Water your plants until the soil is damp 6 to 8 inches (15 to 20 cm) deep. However, be careful not to overwater them. Overwatering can cause the soil to become saturated or runoff.

5. Variety

A fifth important factor that affects tomato flowering and fruiting is variety. Tomatoes come in many different varieties, shapes, sizes, colors, and flavors. Some varieties are more suited for certain climates, seasons, and purposes than others. Some varieties are more prone to flowering and fruiting problems than others.

Washington Cherry

• Determinate varieties: Determinate varieties are tomato plants that grow to a certain height and produce all their flowers and fruits at once, usually within a short period. Determinate varieties are ideal for small spaces, containers, or short seasons. However, determinate varieties may not flower or fruit if planted too late, pruned too much, or affected by adverse weather conditions

• Indeterminate varieties: Indeterminate varieties are tomato plants that keep growing and producing flowers and fruits until they are killed by frost, disease, or pests. Indeterminate varieties are ideal for large spaces, trellises, or long seasons. However, indeterminate varieties may not flower or fruit if they are planted too early, crowded too much, or affected by nutrient or water imbalances.

To fix this problem, you need to choose the right variety of tomatoes for your garden. To learn about a plant’s traits, needs, and how well it grows, read the seed packet, plant tag, or catalog. You can also research online or ask your local nursery or extension office for recommendations. You can also experiment with different varieties and see which ones work best for you.

Conclusion

Tomato plants not flowering or fruiting can be a common and frustrating problem for many gardeners. By knowing the reasons and fixes, you can solve this issue and have a plentiful crop of tasty tomatoes.

Please Remember to Keep your tomato plants in the optimal temperature range of 70°F to 85°F (21°C to 29°C). Protect your plants from cold snaps or heat waves with covers or shades.

Sources and References: 

• Tomato Plant Not Flowering? Here’s What You Need to Do.
• 9 Reasons Your Tomato Plant isn’t Flowering (and How to Fix It).
• Tomato Plants Not Flowering: Causes and Solutions.
• 5 Worst Reasons Why Tomatoes Are Not Flowering

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I am Gaushoul Agam

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ToAgriculture

I am an experienced Horticulture Officer in the Department of Agricultural Extension in Bangladesh. I am committed to improving agriculture and farming.

I created ToAgriculture to address global food safety concerns. These concerns are caused by a growing population, diminishing farmland, and the impact of climate change on agriculture. I assist readers in learning modern farming techniques.

I also help them control pests and diseases. Additionally, I guide managing agriculture sustainably. All of this is aimed at creating a better and more successful future in farming.

I have experience in field crops and horticulture crops. I know about fruit and vegetable farming, managing pests and diseases, irrigation, and grafting. Come with me as I share my knowledge and experiences to help you create a better future.