Circle – 3.14 x radius squared – (Radius is distance from center of circle to perimeter / or half the distance of the diameter) (Radius squared is radius x 2)
Plant Estimating Chart
Example: if you select 18″ spacing and need to cover 300 square feet, the box where that column and row intersect tells you that you need 133 plants.If you don’t see your exact coverage area listed, either estimate by selecting the closest area listed or use the second chart below (“Plant Calculator”) to precisely calculate how many plants you need.
Use the plant calculator below to determine how many plants to use per square foot of space to be planted – particularly ground covers, annuals and perennials.
To accurately use chart you must first know how far to properly space the type of plant you are planting. Spacing is usually listed on the plant description.
Example: you want to cover an area of 120 square feet with a spacing of 10″. For 10″ spacing the plants per square foot is 1.45. Multiply 1.45 x 120 and you get 174 plants needed.
(Area in square feet) x (Plants per Square Foot) = Number of plants needed