11 Tips for Growing Terrific Tomatoes in Pots

Choose a Really Large Pot

Tomatoes need a large container to thrive because of their expansive root systems. Plant tomatoes in a pot big enough so that the tomato plant receives ample water and nutrients during the growing season.

• Each plant needs a container measuring at least 1 square foot or about 2 gallons.
• A larger container of around 2 square feet is better. A 5-gallon bucket, easily found at hardware stores, is the perfect size for healthy tomato plant growth.
• Avoid black containers. Black plastic can absorb and hold a lot of heat, which can cause roots to be overly warm, leading to stunted plants.
• Plastic or fiberglass pots are better choices than clay pots because they don't dry out as quickly. Dry soil is a huge detriment to fruit production.

Use a Container With Good Drainage

Look for a container with good drainage so the roots remain moist but not soggy. If you use a 5-gallon bucket, drill holes in the bottom before filling it with potting soil to allow water drainage.

If the pot you use has large drainage holes, use a piece of a broken pot, a piece of window screening, or a paper coffee filter to cover it. This way the water can drain out, but the soil won't end up all over the patio.

Use the Right Potting Soil

Soil from your yard or garden is too heavy for container gardening and may contain disease organisms. Use a fluffy, light potting mix that allows roots to grow freely and helps moisture and air penetrate to reach them.

Fill your pot with high-quality potting soil to about an inch from the top rim.

Group Containers Together

While the leaves need lots of sun, the root zone of tomatoes can get too hot if the containers are exposed to too much sun. Grouping them provides some shade for the roots and makes watering easier.

Plant Tomatoes Deeply

When transplanting a tomato seedling, remove the bottom set of leaves and plant deep enough that most of the stem is buried.

The tomato plant will produce roots along the buried part of its stem, developing a strong root system and sturdier plants.

Add a Support System

Both determinate and indeterminate container tomato plants will benefit from a support structure. For indeterminate tomato plants, the structure is necessary to support the vining behavior and the weight of the fruit.

The support system should be added to the container when planting each tomato. Waiting until the plant is larger may disturb the growing roots. If you are growing container tomatoes in the yard, the cage can be inserted into the soil outside of the pot.

• Use a traditional tomato cage or stakes for determinate types. Choose a cage about 15 to 20 inches high and 10 inches wide. Larger breeds need a cage at least 38 inches high and 14 inches wide.
• Make supports or purchase tomato cages to elevate indeterminate plants and tie off their stems. Since indeterminate plants grow so large, use a cage at least 38 inches high and 14 inches wide.
• As the tomato plant grows, secure the stems with twine, plant ribbon, or plant wire to the support.
  

Add a Layer of Mulch

Once the tomato seedling is planted, add a 1-inch layer of mulch to the top of the potting soil. Straw, shredded bark, or chopped leaves will help keep the growing medium from absorbing too much heat and help preserve moisture.

Water Soil Consistently

Water plants in the morning to provide hydration all day and enable damp foliage to dry during daylight hours. Apply water directly on the soil and minimize moisture on the leaves, which can encourage blight and fungus. The soil should be moist but not soggy to avoid root rot. 

You may need to water plants twice daily during sweltering summer or hot and windy days. If a tomato plant receives too little water, the plant wilts and weakens, the tomatoes could develop blossom end rot, or the fruit can crack or split.

Fertilize the Tomatoes Regularly

Tomatoes are heavy feeders, and container-grown tomatoes require feeding about every two weeks. Feed your plants the primary required nutrients—nitrogen, phosphorus, and potassium.

Tomatoes grown in pots need to be fed regularly throughout the growing season, as often as twice monthly, depending on the type of potting mix used. A balanced NPK fertilizer, such as 5-5-5 or 5-10-5, works best when added during watering.

Some potting soils already have fertilizers included, so read the soil bag to determine if these essential nutrients are included in the mix.

Find a Sunny and Warm Location

Tomato plants require full sun, which means at least six to eight hours daily between 10 a.m. and 4 p.m.

Place your pots in a location that receives sunlight all day long, and if conditions change throughout the growing season, move the pots to ensure adequate sun exposure.

Tomato plants like warm temperatures. If temperatures drop below 50°F, bring the plants inside or protect them from the cold. If temperatures soar above 90°F, provide more shade, because the plant will stop producing flowers and fruit.

Harvest Ripe Tomatoes

Every variety of tomatoes has a slightly different growth rate and harvesting schedule. Most produce fruit within 60 to 100 days. While you can pick tomatoes when they are not ripe and allow them to ripen off the plant, you will get the best flavor if you allow them to ripen on the plant.

Determine a ripe tomato by:

• Skin sheen: A ripe tomato has a glossy and slightly shiny skin.
• Skin color: The color should be fairly deep and uniform.
• Feel: The tomato should give slightly when giving it a gentle squeeze.
• Stem resistance: Ripe tomatoes should release themselves from the stem with a gentle tug.
• Smell: The tomato should give off a strong tomato fragrance.