Tomato plants grow exceptionally tall due to plant genetics, lack of adequate sunlight, or an excess of nitrogen.
To keep your tomato plants from getting too tall, "top" the plant by cutting off the main growing tip 3-4 weeks before your first expected fall frost. Additionally, pinch off young "suckers" (the shoots that grow in the V-shaped joints of the stem) to stop it from putting energy into new vertical vines.
Baking soda (sodium bicarbonate) is used to control fungal diseases, deter pests, and slightly reduce soil acidity. However, it must be applied with caution; overuse can cause dangerous salt buildup and damage plant tissue.
High Temperatures. Too much warmth can cause spindliness. Though tomatoes love heat and sunshine, too much warmth can promote tall, spindly plants.
When tomato plants grow large and lush but produce no fruit, the most common culprit is a nutrient imbalance (too much nitrogen), extreme temperatures, or poor pollination.
Yes, you can absolutely "top" your tomato plants when they outgrow their stakes, cages, or your reach.
Yes, coffee grounds are good for tomato plants. They add valuable organic matter to the soil, improve moisture retention, and provide a slow-release source of nitrogen, which is especially beneficial during the plant's early growth phase.
Yes, you should stop your tomato plants from growing higher if you have an indeterminate variety that has outgrown its support or if you are at the end of the growing season. This process, called "topping," forces the plant to redirect its energy into ripening existing fruit rather than producing new foliage.
Never plant fennel, brassicas (like cabbage, broccoli, and kale), potatoes, or corn near tomatoes. These plants can stunt tomato growth, compete aggressively for nutrients, or spread devastating diseases and pests.
Encouraging the last few to ripen
The simplest is to bring them into a warm room and place them in a paper bag with a ripe banana or apple. Both release ethylene gas, which encourages ripening. Keep the bag loosely closed, check daily, and you'll often find the tomatoes take on full colour within a week.
Hydrogen peroxide can be highly beneficial for tomato plants if used correctly. It is a cheap, effective, and readily available remedy used to control fungal diseases, manage pests, and aerate waterlogged soil. However, because it is a strong oxidizer, using too much can damage your plants.
The best homemade tomato fertilizer is a nutrient-rich, liquid compost tea. It delivers a gentle, balanced boost of essential macronutrients (nitrogen, phosphorus, and potassium). To make it, steep a shovelful of aged manure or compost in a 5-gallon bucket of water for 24 hours, strain the liquid, and water your plants.
The U.S. Department of Agriculture recommends using baking soda to prevent fungal diseases in tomato plants. Mix 1 tablespoon of baking soda, 1 teaspoon of vegetable oil, a small amount of dish soap, and a gallon of water to make a solution to spray on the plants throughout the season.
How to Support Tomatoes
Yes, trimming leaves is highly beneficial, but you should only remove specific ones. Pruning improves airflow and prevents diseases.
To manage overgrown tomato plants, start by removing any diseased or ground-touching foliage, and trim away the "suckers" (the shoots growing between the main stem and branches) to improve airflow. Untangle the remaining vines and secure them to sturdy stakes, trellises, or tomato cages with soft garden ties.
The best overall companion plant for tomatoes is basil. It thrives in the same growing conditions, repels pests like mosquitoes and thrips, and is widely believed to enhance the flavor of the tomatoes themselves.
When growing tomatoes, avoid planting before the danger of frost has passed, as cold temperatures stunt growth. Do not plant shallowly; bury stems deep in the soil for stronger roots. Never water from above—wet leaves invite blight—and avoid over-fertilizing with nitrogen, which creates bushy leaves instead of fruit.
To stop tomato plants from growing too tall, use the "topping" method: cut off the main growing tip of the plant about 30 to 40 days before your region's first expected fall frost, or when it reaches the top of your trellis or cage. This redirects energy into ripening existing fruit.
Coffee grounds are added to tomato plants because they provide a slow-release source of nitrogen, improve soil structure, and can help deter pests like slugs and snails. They are best used in moderation or mixed into compost rather than piled thickly, as too many can compact the soil.
Cutting the top off a tomato plant stops vertical growth and forces the plant to redirect its energy into maturing existing fruit rather than producing new foliage. However, the exact outcome depends on whether it's done intentionally at the end of the growing season or by accident.
Baking soda lowers the soil's acidity levels, giving you sweeter tomatoes. Sprinkle a small amount—about less than ¼ cup—on the soil around your tomato plants.
The absolute best homemade fertilizer for tomatoes is a balanced, nutrient-rich compost combined with organic matter like crushed eggshells (for calcium) and banana peels (for potassium). This combination prevents blossom-end rot and fuels heavy fruit production naturally.
Epsom salts (magnesium sulfate) provide magnesium and sulfur to tomato plants, which boosts chlorophyll production, aids nutrient absorption, and corrects leaf yellowing. It promotes bushier foliage, stronger cell walls, and can enhance fruit size and flavor.