No flowers? If flowers aren't forming at all, the problem could be a nutrient imbalance in the soil. Excess amounts of nitrogen can encourage lots of leaf growth at the expense of fruiting.
Tomatoes need a tough love approach. First, treat them badly - no feeding, water only essential - they'll think they are about to die and start flowering. Only once they've started flowering do you start feeding and watering at will.
Tomatoes can keep on growing leaves and not produce any tomatoes. This happens when tomatoes drop the flowers to produce foliage rather than fruit. There are 5 main reasons why tomatoes drop flowers. 1. High Temperature, 2. Too much fertilizer, 3. No Sunlight, 4. Too much watering, 5. No 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.
Remove all leafy suckers beneath the first fruit cluster so they won't slow the development of the fruit. Suckers are the little shoots that form in the spot (called an axil) where the leaf stem attaches to the main growing stem. In northern regions, many gardeners go further, removing all suckers as they appear.
Getting a Plant to Flower
While we cannot control things like age or weather, we can fix factors such as light, fertilizer, and pruning. For example, if your plant is not blooming because it is not getting enough light, you can simply move it to a more appropriate location.
Water correctly: Do not overwater. The first week tomato plants are in the ground, they need water every day, but back off watering after the first week, slowly weaning the plants down to 1 to 1.5 inches of water per week.
Some growers prefer to use a high-phosphorus fertilizer, indicated by a larger middle number. You can also keep things simple with a fertilizer especially formulated for tomatoes – usually with a ratio like 3-4-6 or 4-7-10. Most importantly, don't over-fertilize. Too little fertilizer is always better than too much.
Some gardeners recommend you “pinch off” the flowers on your tomato transplants during their first weeks of growth, claiming that removing early blossoms: Directs more energy into establishing a strong root system. Results in a larger, sturdier, and potentially healthier tomato plant.
Tomatoes, squash, peppers, cucumbers, and other vegetables (and herbs!) will thrive when they're fed every 7 to 14 days with Miracle-Gro® Water Soluble Plant Food for Vegetables & Herbs.
Tomatoes are prone to magnesium deficiency later in the growing season, which can show with yellowing leaves and diminished production. Ultra Epsom Salt treatments at the beginning of their planting and throughout their seasonal life can help to prevent and remedy magnesium deficiency in your tomato plants.
Determinate tomatoes will grow to their mature size, then stop. These types of tomatoes do not require pruning to thrive. Once they reach full size, they'll start all their fruit around the same time.
Most vegetable plants will benefit from bone meal applications, but it is especially beneficial for root crops (like carrots and onions), as well as flowering crops (like tomatoes, peppers, and eggplant). Bone meal is also beneficial for any other flowering plants that you may have in your yard or garden.
Overwatering generally makes the plant look almost like it's rotting, as in drooping and turning soggy brown. My guess is it is having Nitrogen problems. Any type of vegetable fertilizer you buy at the store should work fine.
Sunscald. Tomato plants protect their fruit with an umbrella of leaves. In bright, hot weather, fruit exposed to the sun may develop a scalded, or sunburned, spot. This is most common on green fruit.
In general, fertilizers formulated for flowering plants would contain amounts of nitrogen less than or equal to the amounts of phosphorus (i.e. 10-10-10 or 5-10-5). This is because phosphorus encourages flowering. Too much nitrogen will stimulate green leafy growth at the expense of flower production.
For example, some gardeners “pinch back” suckers on their tomato plants. This means removing the shoots that appear in the “V” or “axil” that is created between the branch and the main stem of tomato plants.