Determining Plant Quantity

News Article

Does your garden look as full and lush as you want it to? Are you envious of your neighbor's garden or the flower beds in the park down the street? The problem may be solved by simply planting the correct number of plants. Proper plant spacing is an important key to garden success. Following the recommended plant spacing requirements allows plants to develop fully and fill in the area properly. Proper spacing also prevents the invasion of weeds as well as allowing enough air movement between plants to prevent diseases. Recommended plant spacings are listed on the back of seed packages or on plant identification tags if you buy plants from the garden center.

To determine the correct number of plants needed for a particular area it is necessary to know the area or square footage of the planting bed. For a rectangular bed, multiply its length by its width. This figure represents the area or square footage of your garden. For a round planting bed multiply 3.14 by the radius2 (distance from the center to the edge of the bed2). For a triangular bed, multiply .5 times the base measurement times the height of the triangle. Winding beds require a good rough estimate.

Circle Triangle
Radius 10' Height 25'
Base 20'
3.14x10'x10'=314 sq. ft. .5x20'x25'=250 sq. ft.

Once the total area has been determined, the chart below can be used to determine how many plants are needed per square foot. Multiply the square footage of the planting bed by the plants needed per square foot to determine the number of plants needed. When using plants with different spacing requirements in the same area, estimate the square footage you will need for each plant.

Recommended Spacing Number of Plants per Sq. Ft.
6" 4
8" 2.25
10" 1.44
12" 1
18" .44
24" .25

Example: a 100 square foot garden, using plants with a recommended spacing of 8" would require 225 plants to fill in the area properly (100 x 2.25 = 225).

This small amount of arithmetic will start you on the road to creating a garden that could be the envy of the neighborhood. It will also prevent overbuying or underbuying the number of plants actually needed.

This article originally appeared in the April 29, 1992 issue, pp. , 1992 issue, pp. 61-62.