How Do We Measure Our Plants?

Meredith Gaines — May 03, 2022

Why So Many Sizes?

There is no nursery-wide standard for pot sizes, meaning that container manufacturers can make pots with slightly different dimensions and designs as they see fit. This is also why there might be several different-looking 1 gallon containers out there. Instead, containers are measured by volume (how much soil they can hold); therefore, comparing a gallon of milk to a gallon of soil will look quite different. So, how do we make sense of it all if there’s no decided system? The answer is to focus on the plant’s needs and the volume over the dimensions or look of the container.

Different nurseries have come up with their own system, often numbering or lettering the pots as they increase in size, while some just generalize and measure by volume instead. At FastGrowingTrees.com, we strive to match the container to the needs of the plant and choose to measure by volume. Plants with deeper roots will need deeper pots, while those with more shallow roots will be fine in a container that’s wide but shallow. This is why some of our containers might be taller or wider but labeled the same size.

Just like you shouldn't judge a book by its cover, you also shouldn't judge a plant by its pot! If you need help determining the correct container for your plant, check our guide here, which walks you through all you need to know when it comes to finding the perfect container. If you need help estimating the size based on the height and container size, keep reading!

How Our Plants are Measured

We measure our plants in two ways, first by height and second by container size. Most of our trees will be measured by height. The height is determined by measuring the central leader, starting at the lip of the container to the top. This way, the height of our trees is the actual height we advertise and doesn't include the container. So, rest assured that your 3-4 foot tree will be 3-4 feet tall once planted in your yard!

If the height isn't easy to measure or isn’t fitting for the plant, we choose to sort by container size. For example, slow-growing boxwoods or hollies that might need shaping are better determined by the container size and root mass than the height. Other plants like hydrangeas that need to be cut back for their health when dormant are also lacking a central leader to measure.

Measuring tape next to an olive tree

What to Expect Based on Container Size

Shrubs and Hedges

Container Size

Approx. Dimensions of Container

Soil Volume

Average Height Range of Plant

1 quart

Round, 4 in. x 4 in.

1 qt.

12 in.

2 quarts

Round, 5 in. x 5 in.

2 qt.

12-18 in.

1 gallon

Round, 6 in. x 6 in.

3 qt. or .15 cu. ft.

12-24 in.

2 gallons

Round, 9 in. x 9 in.

5 qt. or .3 cu. ft.

2-4 ft.

3 gallons

Round, 10 in. x 10 in.

5 qt. or .46 cu. ft.

2-4 ft.

5 gallons

Round, 12 in. x 12 in.

12 qt. or .77 cu. ft.

3-4 ft.

 

Endless Summer® Hydrangea Shrub

Evergreen and Deciduous Trees

Container Size

Approx. Dimensions of Container

Soil Volume

Average Height Range of Plant

1 quart

Round, 4 in. x 4 in.

1 qt.

12 in.

2 quarts

Round, 5 in. x 5 in.

2 qt.

12-18 in.

1 gallon

Round, 6 in. x 6 in.

3qt. or .15 cu. ft.

12-24 in.

2 gallons

Round, 9 in. x 9 in.

5 qt. or .3 cu. ft.

2-4 ft.

3 gallons

Round, 10 in. x 10 in.

5 qt. or .46 cu. ft.

3-5 ft.

5 gallons

Round, 12 in. x 12 in.

12 qt. or .77 cu. ft.

4-5 ft.

7 gallons

Round, 14 in. x 14 in.

18 qt. or 1.5 cu. ft.

5-7 ft.

Drop and Grow Bag (decomposable)

Varies by root ball size

Varies

3-7 ft.

 

Thuja Green Giant

Fruit Trees

Container Size

Approx. Dimensions of Container

Soil Volume

Average Height Range of Plant

Citrus pot/C pot

Square, 3 in. x 8 in.

.5 qt.

12-48 in.

1 quart

Round, 4 in. x 4 in.

1 qt.

12-24 in.

2 quarts

Round, 5 in. x 5 in.

2 qt.

1-3 ft.

1 gallon

Round, 6 in. x 6 in.

3qt. or .15 cu. ft.

1-3 ft.

2 gallons

Round, 9 in. x 9 in.

5 qt. or .3 cu. ft.

2-3 ft.

3 gallons

Round, 10 in. x 10 in.

5 qt. or .46 cu. ft.

3-5 ft.

5 gallons

Round, 12 in x 12 in

12 qt. or .77 cu. ft.

4-6 ft.

7 gallons

Round, 14 in. x 14 in.

18 qt. or 1.5 cu. ft.

5-7 ft.

Drop and Grow

Varies by root ball size

Varies

3-7 ft.

 

Elberta Peach Tree

House & Patio & Tropical

Most house plants or tropical plants are difficult to measure by height, as they grow differently or not as large as other plants. Use the age to determine how developed the plant might be instead of the height.

Container Size

Approx. Dimensions of Container

Soil Volume

Approx. Age of Plant

1 quart

Round, 4 in. x 4 in.

1 qt.

Seedling, less than 1 yr.

2 quarts

Round, 5 in. x 5 in.

2 qt.

1 yr.

6 in. pot

6 in. x 4 in.

2 qt.

1 yr.

1 gallon

6 in. x 6 in.

0.734 gallons

1-2 yrs.

2 gallons

Round, 9 in. x 9 in.

5 qt. or .3 cu. ft.

1-3 yrs.

3 gallons

Round, 10 in. x 10 in.

5 qt. or .46 cu. ft.

2-3 yrs.

 

Limequat Citrus Tree

Please note: All containers mentioned above are based on volume measurements. Actual measurements may vary. Volume is measured in cubic feet or quarts of soil needed. Comparing a liquid gallon of milk to a container pot is not an accurate measurement.

    Meredith Gaines

    Meredith's love for plants started at a young age, and only grew when she started working in the Desert Exhibit at the South Carolina Botanical Gardens and the Historic Filoli Estate in the Bay Area. After graduating from Clemson University (GO TIGERS!) with a degree in Biology and Horticulture, she found her niche in the FastGrowingTrees.com family as a horticulturist and has grown in her current role as Senior Plant Expert.

    She currently resides in her hometown of Charlotte, North Carolina, and enjoys spending any time she can outdoors. She learns new things about plants every day and loves sharing her plant knowledge and tips with those around her. Her favorite plant is constantly changing, but her long-time favorites are peonies, oak trees, and ferns.

    Questions? Contact Meredith at information@fastgrowingtrees.com.

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