When to Feed Tomato Plants in Greenhouse

Greenhouses offer a controlled environment for growing tomatoes. With the right temperature, humidity, light, and nutrients, you can improve the chances of harvesting healthy tomato plants. Feeding your tomato plants plays an important role in achieving this goal. However, it can be tricky to know when to feed tomato plants in a greenhouse. This article explores the best time to feed tomato plants in a greenhouse, as well as the nutrients your tomato plants need.

Feeding Tomato Plants in the Early Stages

The early stages of tomato plant growth are crucial. During this time, tomato plants need enough nutrients to promote healthy growth. However, it’s important to exercise caution while feeding your tomato plants during this stage. Applying too much fertilizer can cause seedlings to become nitrogen-burned, leading to stunted growth or dead seedlings.

It’s advisable to add a small amount of balanced liquid fertilizer during transplanting. You can apply it at the bottom of the planting hole to stimulate root growth. Afterward, wait for a week or two before feeding your tomato plants again. During this period, the soil in the planting hole will have enough nutrients to sustain the tomato plant.

Mid-Stage Feeding

Typically, tomato plants in a greenhouse start to show significant growth about 30 to 40 days after transplanting. When this happens, it’s time to start feeding your tomato plants regularly. You can use liquid, granular or slow-release fertilizers, depending on your preference.

When feeding tomato plants in the mid-stage, it’s important to pay close attention to the nutrients you’re using. The three essential nutrients tomato plants require are nitrogen, phosphorus, and potassium. Nitrogen supports leafy growth, while phosphorus enhances root, bloom, and fruit growth. On the other hand, potassium helps control water absorption and prepare the plant for disease and weather changes.

Although tomato plants need all three nutrients, you should note that overfeeding your tomato plants with nitrogen can lead to excessive foliage growth. This consequently leads to fewer fruits and a weak plant structure, which for greenhouse growers means less yield or lower quality.

Feeding During the Fruit Production Stage

When your tomato plants start producing fruits, it’s essential to continue feeding them with the right nutrients. At this stage, tomato plants require more potassium to regulate water absorption and maintain fruit quality. Feeding a high-potassium fertilizer like a 0-0-50 will enhance fruit quality and improve the plant's tolerance to weather changes and disease.

However, it’s important not to overfeed your tomato plants. Overfeeding can cause fruits to become excessively large, which can lead to splitting, rendering the produce unsellable. You can avoid this by controlling the amount of fertilizer applied, as well as monitoring when and how frequently you're feeding your tomato plants.

Conclusion

Greenhouses offer a suitable environment for growing healthy tomato plants. However, using the wrong fertilizers or feeding at the wrong time can lead to stunted growth, low yield or even the death of the plants. When feeding tomato plants in a greenhouse, it’s crucial to follow the recommended guidelines, which include starting with small amounts during transplanting, adjusting the nutrient compositions each growing stage, and avoiding overfeeding to ensure the healthy growth of your tomato plants.