5 Tips for Growing Tomatoes in Pots
Article from The Spruce by Kerry Michaels, updated 4/16/20
Illustration: The Spruce / Maritsa Patrinos
Tomatoes can be challenging to grow in containers, but they continue to rate among the top summer plants in gardens. Here are five controllable factors for successfully growing tomato plants in containers.
A great benefit to growing plants in portable containers is that they are moveable and you can adjust their growing location and several other factors to adjust the growing process. Although, if you have very large containers, you cannot do much against unfavorable weather conditions, late blight, or critter problems. Control
A great benefit to growing plants in portable containers is that they are moveable and you can adjust their growing location and several other factors to adjust the growing process. Although, if you have very large containers, you cannot do much against unfavorable weather conditions, late blight, or critter problems. Control
what you can and hope for the best!
Use really big containers
One of the most important things you can do to ensure tomato success is to use a big enough container—the bigger, the better. For one plant, you need a container that is at least 1 square foot, but 2 square feet is better. Five-gallon buckets are the perfect size for one plant. Fill up the pot with high-quality potting soil and make sure you have good drainage.
Some tomato growers suggest adding herbs or other plants in the pot. Beginners should refrain from adding additional plantings to the pot, even if you have a massive container. You do not want other plants competing with the tomato plant for water.
Some tomato growers suggest adding herbs or other plants in the pot. Beginners should refrain from adding additional plantings to the pot, even if you have a massive container. You do not want other plants competing with the tomato plant for water.
Plant Tomatoes Deeply
Most seedlings are planted shallowly; tomatoes are the opposite. When planting a tomato seedling, dig a hole so that most of your seedling is under the soil. You still need some leaves sticking out of the top of the soil. Remove all the leaves and branches below the soil line. Eventually, roots will develop from stems that are underground. This planting under the soil strengthens the root system, usually leading to healthier plants.
Water Soil Consistently
A tomato's success in a container garden depends on maintaining moist soil. The water content of your soil is one of the biggest challenges. If your soil is fast-draining, you might consider a water-retaining additive, self-watering container, or checking your soil moisture every day. Keep in mind that the ambient heat around a container can warm up the soil more than in-ground plantings, and the water will dry up or get absorbed quicker.
Too little water and your plants will get weak, and your tomatoes will develop blossom end rot. If your plants are getting inconsistent water, then you might notice exploding (or at least cracking or splitting) tomatoes. If you have sweltering summer days or experience hot, windy days, water the plant twice a day. Another trick with tomatoes is to water them in the morning when plants use water more efficiently. Also, water the soil and not the plants. Wet leaves can encourage blight and fungus.
Another important rule of thumb: You need moist soil but not soggy soil. Too much water and your plant's roots will rot. Make sure you have several drainage holes in your containers. If your pot only has one drainage hole, add several more (this is easier to make with metal or plastic containers). If your tomato plant is getting too much rain, flooding the plant and waterlogging the soil, move the pot to a sheltered area or cover it if it is small enough.
Too little water and your plants will get weak, and your tomatoes will develop blossom end rot. If your plants are getting inconsistent water, then you might notice exploding (or at least cracking or splitting) tomatoes. If you have sweltering summer days or experience hot, windy days, water the plant twice a day. Another trick with tomatoes is to water them in the morning when plants use water more efficiently. Also, water the soil and not the plants. Wet leaves can encourage blight and fungus.
Another important rule of thumb: You need moist soil but not soggy soil. Too much water and your plant's roots will rot. Make sure you have several drainage holes in your containers. If your pot only has one drainage hole, add several more (this is easier to make with metal or plastic containers). If your tomato plant is getting too much rain, flooding the plant and waterlogging the soil, move the pot to a sheltered area or cover it if it is small enough.
Feed Your Tomatoes
Make sure you feed your plant the primary nutrients—nitrogen, phosphorus, and potassium—all essential for growing almost anything in containers. Some potting soils have nutrients in them. Read the soil bag and check to see if these essential nutrients are in the mix. If your potting soil does not have nutrients added, give the plant an all-purpose slow-release fertilizer or a tomato-specific fertilizer.
Let the Sun Shine
When deciding where to grow your tomatoes, you will need to find a place where they will get enough sun. Tomatoes will grow well with at least 6 hours of full sun, but more than 8 hours is better. Either use a measuring device like a sun calculator or go out and check your tomato containers several times during the day and log how much sun they are getting.
If your plants aren't getting enough sun, move them. Continuously monitor the location throughout the growing season; the sun moves across the sky over time. What was once a full-sun area can become a shady spot during a critical part of the day.
While tomatoes love the sun, too much sun as seedlings can kill the plants if they are not hardened off or slowly acclimated to outdoor growing conditions. Too much early exposure to wind and sun can weaken or destroy your small plants. Also, tomatoes like heat, so do not put them out when it is cold. If temperatures drop colder than 60 degrees, bring the plants inside. If the plants get too hot (more than 90 degrees sustained over time), the plant will not produce flowers or fruits will not mature.