What Size Pot for Tomatoes & How Much Potting Soil Do I Need

Growing tomatoes in containers are very popular for gardeners who have space limitations. Besides, some hobby gardeners also try potting tomatoes for new experiments and other purposes. Nonetheless, choosing the right size of pots for your different tomato varieties is a little bit confusing for beginners.

People often ask, “What size pot for tomatoes?”.

That’s why I tell you today which container size best suits your particular tomato variety and how much potting soil you actually need for that pot.

Pick the Right Pot for the Right Tomato Variety

Take a larger container as you can. The more room you give to your potting tomatoes to develop a strong root system, they will produce more fruits.

But when you have space limitations, then you should pick a standard-size container that performs better for your particular tomato variety.

To identify your tomato plant height, see the seed packet instructions or tomato plant tags. Then, pick the right container size for your tomatoes based on the plant’s height.

Besides, when you buy containers from gardening stores or online stores, you may find the exact size of containers in different dimensions.

For example, you may find a 1-gallon container in different dimensions, such as –

– 7″ wide × 7″ height

– 8″ wide × 6″ height

– 7.5″ wide × 7″ height

Usually, determinate and dwarf tomato varieties are best suited for containers. On the other side, indeterminate tomatoes best perform in the ground. However, you can grow any tomato in the pot based on the container’s shape and size.

Potting Size for Dwarf Tomatoes

Dwarf tomatoes are mainly container varieties. They can grow 6-18″ tall and need a comparatively smaller container size.

Dwarf Tomato Plants Height	Dimension of Containers Width × Height	Standard Container Size
5″-6″ tall	6″ × 6″	½ -Gallon Pot or bigger
6″-15″ tall	7″ × 7″ 8″ × 6″ 7.5″ × 7″	1- Gallon Pot or bigger
12″-18″ tall	9″ × 8″ 8″ × 7″ 8.5″ × 8.5″ 9″ × 8.5″	2- Gallon Pot or bigger

Potting Size for Determinate Tomatoes

The average height of determinate tomatoes is around 24-48″. So, based on your plants’ height, you may pick the following size of pots for your tomatoes.

Determinate Tomato Plants Height	Dimension of Containers Width × Height	Standard Container Size
18″-36″ tall	10″ × 9″ 10″ × 8.5″ 11″ × 9.5″ 11.5″ × 8.5″	3-Gallon Pot or bigger
36″-48″ tall	12″ × 11″ 13″ × 10″ 12″ × 10.5″ 14″ × 10″	5-Gallon Pot or bigger

Potting Size for Semi-Determinate Tomatoes

Semi-determinate tomatoes can grow 4-5 feet tall based on the variety. And they need the following sizes of containers.

Semi-Determinate Tomato Plants Height	Dimension of Containers Width × Height	Standard Container Size
48″-60″ tall	14″ × 12″ 14″ × 11.5″ 14″ × 10.5″	7-Gallon Pot or bigger

Potting Size for Indeterminate Tomatoes

Indeterminate tomatoes can rise to around 5-9 feet taller or more. Therefore, they need comparatively larger containers than other tomato varieties.

Indeterminate Tomato Plants Height	Dimension of Containers Width × Height	Standard Container Size
60″-72″ tall	16″ × 13″ 15″ × 15″ 16″ × 11.5″ 16″ × 12.5″ 18″ × 12″	10-Gallon Pot or bigger
72″-84″ tall	18″ × 14″ 16.5″ × 15″ 20″ × 14″	15-Gallon Pot or bigger
84″-108″ tall	20″ × 16″ 20″ × 14.5″ 21″ × 15″	20-Gallon Pot or bigger
108″ tall or higher	24″ × 16″ 22.5″ × 18.5″	25-Gallon Pot or bigger

How Much Potting Soil Do I Need to Fill My Tomato Pots

The amount of potting mix exactly needs to fill up a container depends on the size of the containers and their dimensions. Besides, the actual container size also varies on the manufacturer.

You may also face the following issues when you are going to fill up your containers:

Liquid vs. Dry Measurement

Potting mixes are measured in dry quarts, dry liters, a gallon, or dry cubic feet. On the other hand, containers are measured in liquid quarts, liquid liters, or a liquid gallon or liquid cubic foot.

Therefore, when you purchase a potting soil bag to fill up a liquid-gallon container, you should know some basic measurements.

1 liquid gallon (U.S) = 4 liquid quarts (U.S)

4 dry quarts (U.S) = 1.16364 liquid gallon (U.S.)

One dry quart (U.S.) = 1.10 dry liters (U.S.)

One dry cubic foot = 28.32 dry liters (U.S.)

One dry cubic foot = 25.71 dry quarts (U.S.)

One liquid gallon (U.S.) = 3.4375 dry quarts (U.S.)

One liquid gallon (U.S.) = 3.79 dry liters (U.S.)

Also, one liquid gallon (U.S.) = 0.86 dry gallons (U.S.)

So, a 1-gallon container doesn’t need precisely 1-gallon potting soil.

Soil Moisture and Compression

The potting soil’s moisture level also helps determine how much potting mix is required for your container. Soil moisture controls the compression level of the dirt into the pot. So, pressuring the potting soil may add a 15-20 percent extra potting mix to the container.

Besides, during transplanting your tomato plants, you will also bring some soil that sticks to your plant roots.

So, after considering the above issues, I can give you an approximate idea of how much potting soil you should need to fill up your desired container.

Potting Soil Measurement for Your Plastic Nursery Pot

Container Size	Standard Dimensions of the Container	Potting Soil Measure for Clay Or Black Plastic Nursery Pot (In Dry U.S. Quart, Liter, and Cubic Foot)
½ Gallon	6″ wide × 6″ height	2.7 QT. = 2.97 L. = 0.10 CU. FT.
1 Gallon	7″ wide × 7″ height 8″ wide × 6″ height 7.5″ wide × 7″ height	4.1 QT. = 4.52 L. = 0.16 CU. FT. 4.37 QT. = 4.81 L. = 0.17 CU. FT. 4.63 QT. = 5.10 L. = 0.18 CU. FT.
2 Gallons	9″ wide × 8″ height 8″ wide × 7″ height 8.5″ wide × 8.5″ height 9″ wide × 8.5″ height	7.71 QT. = 8.50 L. = 0.30 CU. FT. 5.14 QT. = 5.66 L. = 0.20 CU. FT. 7.2 QT. = 7.93 L. = 0.28 CU. FT. 7.97 QT. = 8.78 L. = 0.31 CU. FT.
3 Gallons	10″ wide × 9″ height 10″ wide × 8.5″ height 11″ wide × 9.5″ height 11.5″ wide × 8.5″ height	10.54 QT. = 11.61 L. = 0.41 CU. FT. 10.03 QT. = 11.04 L. = 0.39 CU. FT. 13.37 QT. = 14.72 L. = 0.52 CU. FT. 13.11 QT. = 14.44 L. = 0.51 CU. FT.
5 gallons	12″ wide × 11″ height 13″ wide × 10″ height 12″ wide × 10.5″ height 14″ wide × 10″ height	18.51 QT. = 20.39 L. = 0.72 CU. FT. 19.8 QT. = 21.80 L. = 0.77 CU. FT. 17.74 QT. = 19.54 L. = 0.69 CU. FT. 22.89 QT. = 25.20 L. = 0.89 CU. FT.
7 Gallons	14″ wide × 12″ height 14″ wide × 11.5″ height 14″ wide × 10.5″ height	27.51 QT. = 30.30 L. = 1.07 CU. FT. 26.23 QT. = 28.88 L. = 1.02 CU. FT. 24.17 QT. = 26.62 L. = 0.94 CU. FT.
10 Gallons	16″ wide × 13″ height 15″ wide × 15″ height 16″ wide × 11.5″ height 16″ wide × 12.5″ height 18″ wide × 12″ height	38.83 QT. = 42.76 L. = 1.51 CU. FT. 39.34 QT. = 43.33 L. = 1.53 CU. FT. 34.46 QT. = 37.94 L. = 1.34 CU. FT. 37.29 QT. = 41.06 L. = 1.45 CU. FT. 45.51 QT. = 50.12 L. = 1.77 CU. FT.
15 Gallons	18″ wide × 14″ height 16.5″ wide × 15″ height 20″ wide × 14″ height	52.97 QT. = 58.33 L. = 2.06 CU. FT. 47.83 QT. = 52.67 L. = 1.86 CU. FT 65.57 QT. = 72.21 L. = 2.55 CU. FT
20 gallons	20″ wide × 16″ height 20″ wide × 14.5″ height 21″ wide × 15″ height	74.83 QT. = 82.40 L. = 2.91 CU. FT. 67.89 QT. = 74.76 L. = 2.64 CU. FT. 77.4 QT. = 85.23 L. = 3.01 CU. FT.
25 gallons	24″ wide × 16″ height 22.5″ wide × 18.5″ height	107.74 QT. = 118.65 L. = 4.19 CU. FT. 109.54 QT. = 120.63 L. = 4.26 CU. FT.

The above table will give you an approximation of how much potting soil is needed for growing tomatoes in a single container. However, the volume of potting mix may change due to the change in the container dimension.

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