Understanding Plant Sizing & Grading

Plants at nurseries are often identified by size. Size measurements vary and can either represent the size and type of container it's in, the caliper of the trunk of the current height of the plant.

Size and Type of Container

bare root trees

Bare Root

Bare root plants are available for sale with no soil, pot or container. At this stage they are often young or newly transported and are therefore quite delicate and susceptible to damage. Bare root plants must be handled with care, must not be allowed to freeze or dry out or the plant may fail to grow. Not all plants are available bare root and those that are, are usually only available at certain times of year. Plants that are typically available as bare root include fruit trees, small flowering trees, roses and certain varieties of perennials such as iris, dahlias and hostas.
potted plants

Potted Plants

Most plants available at Art's Nursery are sold in pots. These pots may vary in size, style, colour and shape. The size of potted plants is loosely measured in by width, soil volume and plant quality.

The width of the pot is a common way to describe smaller pot sizes. For example:

  • 4cm
  • 9cm
  • 4 inch
  • 5 inch
Plants often found in these sizes are annuals, perennials, grasses, groundcovers and other smaller plants.

Pots are also described by their capacity or soil volume. This method is often used for mid to large sized plants like larger perennials, roses, shrubs and trees. In the past, pot sizes were typically described as:

  • 1g or 1 Gallon
  • 2g or 2 Gallon
  • 3g or 3 Gallon
  • 5g or 5 Gallon
Generally speaking. the larger the number, the larger the pot, and usually, the larger the plant.

Over time, many different pot manufacturers have sprung up, causing much confusion in the industry about a pots real capacity. In fact, in the United States, government regulations were passed several years ago that mandated growers to put the actual soil capacity of their pots on their labels. Unfortunately, no such law is available in Canada. Today, most pots are not actually capable of holding the stated capacity of soil, but the convention has remained for sake of convenience. Many nurseries and growers now call them #1, #2, #3 and so on, but they are usually referring to the same approximate pot size.

Grading As with most things in life, not all things are created equally. As their are many different growers of plants, the variation in plant size within a given pot can be extreme. For example, one grower may ship a plant in a #1 pot size that may be just a few bare twigs, while another may ship the same plant, in the same pot, but it could be big, beautiful and lush. To account for these discrepancies in plant size, we classify plants by include grading information along with the size. For example:

  • P - Premium Grade
  • G - Regular Grade
  • L - Light / Landscape Grade

For example, a plant may be #2P (#2 pot size, premium) or #3L (#3 pot size, landscape grade).

You can typically expect Premium grade plants to be healthy and big for their pot size, but usually at a slightly higher cost. This quality difference may be due to better growing conditions, better plant care, or just simply more time in the pot before being sold. Inversely, Light or Landscape grade plants may be smaller, not perfectly grown and possibly mediocre in quality, but typically cost less. It is this grading that makes it very difficult to price compare plants. Bottom line, if price is a concern, you really need to see what you are getting for the price being charged. At Art's we strive to offer the biggest, healthiest plants from the best quality growers in our area, or from other sources at the best possible price.

balled and burlapped plants

Balled & Burlapped (B&B)

B&B or balled and burlapped plants have their root systems contained within a burlap sack held together with twine or rope.
B&B is typically used for larger plants like trees, hedging cedars and shrubs. When planting B&B plants, cut away any rope or twine, but leave the burlap on.
wire cage plants

Wire Cage

Wire cage plants are also balled and burlapped, but due to the size of the rootball, rope or twine is insufficient to hold the package together. Instead, wire is used to wrap the burlap. Plants of these sizes are often very heavy and very large. Machinery is typically required to move or install them.
caliper plants


Caliper is another measure of plant size. A device called a 'caliper' is used to measure the width of the trunk several inches above the top of the rootball. The caliper is also usually described in either centimeters or inches. For example, when landscaping a new home, city regulations might state that you have to plant a 5cm caliper tree. Obviously, the larger the caliper, the older and larger the tree.
height of plants

Plant Height

The final method of measuring a plants size is to measure it's current height. This method is often used for hedging cedars, conifers and other larger trees and is often described in metres. For example, during a landscape project, city regulations may state that you have to plant a 3 metre high tree. Again using common sense, the larger the tree, the more expensive it will probably be given the amount of time the grower needed to get it to size.
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