What is the Best Size Container for Growing Tomatoes?

Tomatoes Are a Favorite of Home Gardeners

Growing vegetables in containers has become increasingly popular, especially for high-yield crops like tomatoes, peppers, and even corn.

According to a national survey of 2,000 U.S. residents conducted by OnePoll, corn ranks as America’s most liked vegetable, with over 91.4% of respondents naming it a favorite. Potatoes came in a close second at 91.2%

Carrots and tomatoes tied for third at 89%. Millions of home gardeners grow tomatoes in pots due to limited space or soil concerns.

There are numerous keys to success, but it starts with understanding how big a pot a tomato plant needs to flourish and produce substantial yields.

“Most container gardening problems don’t start above the soil. They start at the roots. Plants need consistent moisture and access to nutrients in the root zone. When those conditions fluctuate, growth slows, and fruit production suffers.” – Mark Bolt, Vice President of EarthBox^®.

Recommended Container Sizes for Tomatoes

Container size plays a significant role in how well tomato plants develop and produce. While small varieties can survive in compact pots, larger containers support healthier roots, more stable moisture levels, and stronger yields.

Container Size Guidelines for Tomatoes

Indeterminate tomato varieties continue to grow and produce fruit throughout the season, making larger containers essential for sustained root development and consistent yields.

• Minimum: 5-gallon containers (about 12 inches wide and deep) for compact, patio, or cherry tomato varieties
• Better: 10-gallon containers for medium-sized plants
• Ideal for best production: 15–20+ gallon containers or pots with an 18–24 inch diameter, especially for indeterminate tomatoes

Smaller containers dry out faster and require more frequent watering and feeding, which can stress plants and reduce fruit production over time.

How Deep and Wide Should the Tomato Planter Be?

Dwarf varieties aside, the bottom line is that each tomato plant needs sufficient horizontal and vertical space to support root development. A 12-inch diameter garden container will work for most tomato plants.

Depth is another consideration relating to container size. Tomato plants root at a medium depth, so they need at least 12 inches of depth.

If you want to grow indeterminate tomato varieties, you'll likely want to scale up with your garden container. These varieties typically grow nearly twice as large as their bush tomato counterparts.

Here, you may need a garden container up to 24 inches deep with a similar diameter.

Why a Bigger Planter is Generally Better for Tomatoes

Independent of variety, you may want to choose a larger container from the get-go for your tomato plants.

In practical terms, larger containers give tomato plants access to more soil, which acts as both a water reservoir and a nutrient buffer. This added volume helps prevent rapid drying during hot weather and reduces the risk of nutrient deficiencies that can occur when roots are confined to small spaces.

Larger Containers Support Root Growth and Healthier Plants

A larger garden container provides more room for the roots to grow. The better the root system, the healthier your tomato plants. And the healthier your tomato plants, the bigger your harvest. Healthy root growth also helps ward off diseases like blossom end rot.

Larger Containers Help Maintain Consistent Moisture

In container gardening, water management is often the difference between healthy plants and disappointing results. Shallow watering causes roots to stay near the surface, making plants more vulnerable to heat stress and nutrient deficiencies.

Bottom-watering systems promote deeper root growth, helping plants access moisture more efficiently and withstand temperature swings.

“Traditional pots rely on frequent guesswork watering. Self-watering systems remove that inconsistency. When water is delivered from below, roots grow deeper, plants stay healthier, and gardeners see more reliable harvests over time.” – Mark Bolt, VP of EarthBox^®.

It stands to reason that larger garden containers hold more moisture. That's a massive plus for tomato plants, as they require regular watering. It also takes less effort and time to water plants.

Larger Planters Add Stability for Tall, Heavy Tomato Plants

Larger tomato planters are more stable than smaller ones. Tomato plants can get pretty significant, up to six feet tall. That more extensive base can prevent your tomato plants from tipping over.

So, if you’re torn on how big your container must be for your tomatoes, size up.

Other Factors in Choosing a Garden Container

In addition to size, there are a few other factors to consider when growing in pots. For the ultimate guide on how to grow tomatoes in containers, click here.

But here's a glimpse into other factors to consider when choosing garden containers, beyond size.

Potting Mix

You can't fill your tomato planter with just any potting mix. It needs to be light for optimal drainage and aeration. It also needs to be dense with organic matter, such as manure compost. Tomatoes are heavy feeders and benefit from a nutrient-rich mix.

Drainage

Ensure your garden container has drainage holes in its base. Otherwise, plant roots wind up sitting in swampy soil.

The exception is self-irrigated planters (SIP). They store water in a reservoir, ensuring water is consistently available to plants. That ready moisture supply enhances plant health and vigor, leading to better yields. It also minimizes the task of watering for you.

For example, EarthBox planting boxes use this self-watering feature. They're a favorite among container gardening beginners and enthusiasts alike, who rate them 4.9 out of 5 stars.

Garden Container Material

Various materials are available for tomato planters: terracotta, fabric, wood, and plastic. Each has its pluses and minuses. But when in doubt, opt for a plastic garden container. They're lightweight, durable, and retain moisture well.

One caveat. It's best to avoid black plastic containers. Tomatoes are sun-loving plants. Unfortunately, black containers absorb heat in a hot sun. That can damage plant roots and increase your watering frequency.

Common Mistakes Gardeners Make When Growing Tomatoes in Planters

Many gardeners struggle with container vegetables not because of plant choice, but because of avoidable setup issues.

Overwatering from the top, poor drainage, inconsistent feeding, and containers that are too small can all limit plant growth and reduce yields. Choosing a system that balances water, soil volume, and nutrients helps eliminate many of these problems before they start.

“When people say container gardening doesn’t work, it’s usually because the system is fighting the plant. When the container supports the plant’s natural growth habits, success becomes far more predictable.” – Mark Bolt, VP of EarthBox^®.

EarthBox: The Best Planter Boxes for Tomatoes

You can remove the guesswork from selecting how small or how large a container to use for tomatoes with an EarthBox. It’s a proven container solution among home gardeners, explicitly designed to support healthy tomato growth and consistent yields.

First, you'll get a satisfaction guarantee.

Second, you'll get an all-inclusive solution with their tomato planter kit. It includes:

• Tomato Planter
• Reversible weed covers
• Staking/Trellis System
• Soft-coated wire ties to secure plants to the Staking System
• 6 Casters/Wheels
• Fertilizer & Natural Dolomite lime
• Tomato & Veggie Boost
• Organic Potting Mix

Third, you'll have the confidence of knowing that thousands of gardeners use EarthBox boxes to ensure their success.