How to Fertilize a Tomato Plant in a Pot – Gardening Questions

Happy June everyone!

This month we are answering the question “I’m growing a tomato plant on my deck in a pot, how do I go about fertilizing it?“

Growing tomatoes in containers is becoming more popular than ever. Whether it’s planting a mini cherry tomato plant in a small pot on your back patio to enjoy for salads or snacking, growing a few slicing tomatoes in a hanging tomato grow bag or large containers – the sky is the limit when it comes to growing tomatoes outside of a traditional garden setting.

Planting and maintaining tomatoes in containers is far easier than in a traditional garden. There is no need for heavy tilling or digging to plant. Nor is there the worry of constant weeding once the plant starts to grow. Best of all, when growing in pots and containers, you are less likely to encounter many of the pests, diseases, and growing issues that tomatoes can often have. With your plants being off the ground, pests have a harder time attacking. As for disease and growing issues, the chance of tomato blight and blossom rot is severely reduced as well since the tomatoes are growing in fresh new potting soil each season. One thing you do need to do with container tomatoes is providing them with plenty of power, and that means fertilizing is a must!

Tomato plants require a tremendous amount of nutrients to grow and produce their fruit. Even in a traditional garden or raised bed setting, tomato plants almost always need more nutrients than the surrounding soil can provide. But when growing in a container, that need is multiplied. Because of the limited soil space, tomato plants in containers use up the available nutrients quickly.

That is why it’s so important to start fertilizing tomatoes growing in containers right from the start. The fertilizer you provide needs to be given in small but steady doses. Too much or too powerful of fertilizer will cause your tomato plants to grow enormous amounts of foliage. They may look dark green and healthy, but unfortunately, they are spending all of the excess energy on growing only foliage and roots – and not blooms. Under-fertilizing will cause the plant to grow at too slow of a pace. And, that in turn will lead to a smaller harvest as well. So how can you fertilize your tomato plants in containers just right? The answer is to simply provide your container tomato plants with a light but a very steady and consistent dose of nutrients – and the easiest and best way to do that is with liquid fertilizer.

Liquid fertilizers are perfect for tomato plants in containers for a couple of very big reasons. They can absorb into the plants quickly. Both through the roots as the liquid leaches into the soil – and through the leaves and stems. Weakening the strength of the fertilizer, you can then give your plants a lighter but more regular dose of energy – allowing them to grow at the perfect slow and steady pace. Giving a light and steady dose, the feedings should be applied every 7 to 10 days – and right from the start! When growing any edibles, it is always best to choose an organic fertilizer, like manure, kelp, compost, or worm castings. You can make a compost tea with any of these by steeping 1 cup of castings/manure in one gallon of water and allowing it to soak in for a few days. Shake up or stir the castings a few times each day to help them soak into the water. Then simply strain and water your plants when they’re thirsty!

If you would like me to answer one of your questions next month you can send your question to me at in**@th*******.ca attention Ask Anna.

Be sure to stop by Harvest Market on the corner of Powerdam and Vincent Massey and say hi while looking through all the beautiful plants in the garden centre. I can guarantee that you will go home with a full trunk!