How to Grow Tomatoes in a Planter: A Step-by-Step Guide

Benefits of Growing Tomato Plants in a Container

Let's start with the obvious. Not everyone is fortunate to have a tillable garden space. But tomato plant planters remove that worry, allowing even urban dwellers to grow them.

Tomato plant containers like those from EarthBox are less than 30 inches long and slightly more than 13 inches wide. So, they demand little space to deliver substantial results.

Their size also makes them portable. Optimize sunlight or transfer the container to a cooler location when the thermometer hits 97 degrees. Tip: Tomato plants stop growing if temperatures exceed 95 degrees Fahrenheit.

Most of all, growing tomatoes in pots puts you in charge. You control the soil quality, moisture levels, sunlight exposure, and plant care. You know the types of fertilizers and pesticides you use. So, if organic tomatoes are your goal, you'll know whether they are or aren't.

And one more thing: Watching your plants grow and seeing tiny flower heads grow into ripe tomatoes can be a pleasurable experience.

Selecting the Right Varieties for Your Tomato Planters

Unless you're a botanist, you'll likely be unaware of the more than 10,000 tomato varieties. Fortunately, we'll narrow that list considerably to make finding suitable varieties easier.

The first step is considering whether to plant a determinate or indeterminate variety in your tomato plant container.

Determinate tomatoes grow to a fixed size and produce fruit all at once. Mature sizes can range from 18 to 36 inches. Known as bush tomatoes, they're ideal for container gardening because they're more compact and manageable. Popular varieties include Patio Princess Tiny Tim, Bush Early Girl, Micro-Tom, Patio Plum, and Tumbler Hybrid.

Indeterminate tomatoes continue to grow and produce fruit throughout the season. They require more space and support using cages or stakes. Smaller plants start at five feet but can easily reach upwards of 12.

The upside is they'll produce more tomatoes. The downside is they can outgrow your tomato planter in short order. Popular varieties include Beefsteak, Sun Gold, Big Boy, San Marzano, and Sweet Million.

Choosing Your Tomato Plant Planter

Don't drive by your local garden center and pick up old containers. You must pay attention to its size, both in depth and width.

First, tomato plants can grow wide and need space to spread. Second, they have a deep and substantial root system.

Your tomato planter should be at least 18 inches in diameter and 12 inches deep. Larger containers are preferable as they provide more space for roots to grow. Equally important, larger tomato plant containers hold more soil to retain moisture better.

Materials for Tomato Plant Containers

Different materials have unique advantages and drawbacks. Some of the more common planters for tomatoes include:

• Plastic: Plastic is lightweight, affordable, and retains moisture well. However, depending on the manufacturer, it may not be as durable. You should note that black plastic containers absorb heat, so you might want to select a different color.
• Wood: Wood is aesthetically pleasing and good for insulation but can rot over time if not treated. In addition, some treated options can leech chemicals into the soil.
• Fabric: This material allows excellent aeration and drainage but may dry out more quickly. Fabric tomato planters have a short life span.
• Terra Cotta is readily available and inexpensive. It can become fragile, especially in temperature extremes. Owing to its porosity, the soil dries out more rapidly.
• 5-Gallon Bucket: A 5-gallon bucket has suitable dimensions for a tomato planter, so if you have some sitting around, you're in luck.

Drainage and Aeration

Proper drainage is crucial to prevent root rot and other water-related issues when growing tomato plants in containers. Ensure that your planter has several drainage holes at the bottom. For aeration, use lightweight potting soil designed for container gardening. Check for ingredients like perlite or vermiculite to enhance air circulation within the soil.

EarthBox Offers the #1 Tomato Plant Container

For serious results, consider buying an EarthBox tomato plant container. Its planter and growing system are lab-tested and proven to perform, and it even comes with a guarantee.

Best of all, the planter is a one-stop solution offering:

• Tomato planter box
• Aeration screen
• Water fill tube
• Mulch cover

You'll also like this. The planter box is self-watering, so all you have to do is keep the reservoir full. The planter does the rest by keeping water available to plant roots as needed—no more worries about adding too much water or not enough.

You can also purchase a complete tomato growing kit with fertilizers, tomato boost, and a staking system.

Preparing the Soil for Your Tomato Planter

Use a high-quality potting mix rather than garden soil. Potting mixes are lighter, provide better drainage, and are free from soil-borne diseases and pests. You can amend the soil with compost or well-rotted manure to improve fertility and provide essential nutrients.

Tomatoes are heavy feeders, requiring a steady supply of nutrients throughout the growing season. At planting time, start by adding a slow-release fertilizer to your soil mix.

Planting Your Tomatoes

With the above steps, you're ready for the fun part—planting. You have two options. First, you can use a seed packet.

The upside is you'll only pay a couple of bucks. And you'll get to see your tomato plants grow from scratch. To get a jump, you can plant the seeds indoors early in spring before temperatures rise to suitable levels.

Use seed trays or small pots filled with a seed-starting mix. Keep the soil moist and provide plenty of light from a sunny window or grow lights. Once the temperatures rise, you move your tomato planter outdoors.

The other option is using transplants. You'll pay a bit more, roughly $5 per plant. But your tomato plants will be ready to plant immediately.

How to Plant Tomatoes in Containers

When using transplants, plant them deep. Typically, you plant the root ball and stem at the soil level. But with tomato plants, you'll want to snip off some of the bottom leaves and plant some of the stems underneath the soil. That will help encourage root growth and create a stronger root system.

Space plants adequately to allow for air circulation and growth. For determinate varieties, space plants 18-24 inches apart. For indeterminate varieties, space plants 24-36 inches apart.

Before planting, ensure the soil is well-prepared and moist. Dig a deep hole to accommodate the root ball and part of the stem. Place the plant in the hole, fill in with soil, and gently press down to eliminate air pockets.

After planting, mulch around the base with straw or wood chips. Mulch helps retain moisture, regulate soil temperature, and suppress weeds. Apply a 2-3 inch layer, keeping it a few inches away from the stem to prevent rot.

Caring for Your Tomato Plants

Caring requires a focus on two essentials: water and fertilizer.

Water consistently to keep the soil moist but not soggy. Tomatoes need about 1-2 inches of water per week. Water deeply at the base of the plant to encourage deep root growth.

A good rule is to water until you see water coming out of the drain holes. Avoid overhead watering, which can lead to fungal diseases.

Use a balanced fertilizer like 7-7-7 or 10-10-10 every 4-6 weeks. Another option is to use a water-soluble fertilizer and fertilize your plants when you water. Additionally, supplement with calcium sources such as crushed eggshells or lime to prevent blossom end rot.

Staking and Pruning Tomato Plants in Containers

Use stakes, trellises, or tomato cages to support the growing plants. Staking prevents the plants from sprawling on the ground, reduces disease risk, and makes harvesting easier. Install supports at the time of planting to avoid disturbing the roots later.

Prune suckers (side shoots) that grow between the main stem and branches to focus the plant’s energy on fruit production. Remove yellowing or diseased leaves to improve air circulation and reduce disease risk.

Pest and Disease Management

Inspect plants regularly for signs of pests, such as aphids, whiteflies, and tomato hornworms. Check both sides of the leaves and around the base of the plant.

Use organic pest control methods such as neem oil, insecticidal soap, or handpicking pests off the plants. Introduce beneficial insects like ladybugs and predatory wasps to help control pest populations.

Prevent diseases by practicing crop rotation, using disease-resistant varieties, and removing diseased plant material promptly. Water at the base of the plant and avoid overhead watering to reduce the risk of fungal diseases. Ensure good air circulation by spacing plants properly and pruning as needed.

Harvesting and Enjoying Your Container Tomatoes

Most tomato varieties require 60 to 100 days from sowing to produce fruit. Tomatoes are ripe when they have reached full color and feel slightly firm to the touch. The specific color will depend on the variety, ranging from red and yellow to green and purple.

Ready to Grow Tomatoes in a Planter?

There you have it. Growing tomato plants in containers is simple work. By following these steps, you'll be well on your way to growing delicious, juicy tomatoes in your planter boxes. Happy gardening!