Planning a Mass Planting

To plan for a mass planting, first you must know how much space you are about to plant, measured in square feet. Multiply the length of the garden by its width (all measured in feet). This figure will be the area of the garden in square feet.

Example:
Length = 15 feet
Width = 5 feet
Total = 75 square feet

When using the following charts, find the factor that will calculate the total number of plants for the garden when multiplied by the garden’s square footage.

Plant and Bulb Spacing

Number of plants or bulbs per 100 square feet if planted on:

Square Spacing
02” centers = 3600 (36 per sq. ft.)
03” centers = 1600 (16 per sq. ft.)
04” centers = 900 (9 per per sq. ft.)
06” centers = 400 (4 per per sq. ft.)
08” centers = 225 (2.25 per sq. ft.)
12” centers = 100 (1 per sq. ft.)
15” centers = 64 (.64 per sq. ft.)
18” centers = 45 (.444 per sq. ft.)
24” centers = 25 (.25 per sq. ft.)
36” centers = 12 (.111 per sq. ft.)
48” centers = 07 (.0625 per sq. ft.)

Triangle or Zig-Zag Spacing
02” centers = 4150 (41.5 per sq. ft.)
03” centers = 1782 (17.8 per sq. ft.)
04” centers = 1000 (10 per per sq. ft.)
06” centers = 461 (4.61 per per sq. ft.)
08” centers = 263 (2.6 per sq. ft.)
10” centers = 166 (1.66 per sq. ft.)
12” centers = 115 (1.15 per sq. ft.)
15” centers = 74 (.738 per sq. ft.)
18” centers = 51 (.512 per sq. ft.)
24” centers = 27 (.27 per sq. ft.)
36” centers = 19 (.189 per sq. ft.)
48” centers = 08 (.0725 per sq. ft.)

Round Beds
Round beds require a bit more effort to figure out. Below is the calculated square feet for certain circular sizes. Decide on the method of planting desired, the spacing required for the plants, and multiply to get the estimated number of plants required.

Diameter in Feet	Sq. Ft.
02	3.75
03	7.0
04	12.5
05	19.5
06	28.25
07	38.5
08	50.25
09	63.5
10	78.5
12	113.0
14	154.0
16	201.0
18	254.4
20	314.1
22	380.0
24	452.3
26	530.8
28	615.7
30	706.7
32	804.1
34	907.7
36	1017.7

The following example shows what a round bed 12 feet in diameter of Giant Liriope would require for complete coverage at 18 inch zig-zag spacing.

Example:
Plants per square foot 000.512
Square feet in bed 113.
Total plants needed 58.

Note: You can use larger spacings, but the longer the plants take to cover the ground, the longer you have to keep weeds from taking over the planting.