How to Determine Plant Quantity for Planting Beds

planning a garden bed by Paul Maguire AdobeStockProper plant spacing is an important key to garden success. Following the recommended plant spacing requirements allows plants to develop fully and properly fill the area. Proper spacing also prevents the invasion of weeds and allows enough air movement between plants to prevent diseases. 

Recommended plant spacings are listed on the back of seed packages or on plant identification tags. Reference materials like books and trusted websites can also provide recommended spacing for your plants. 


Find the Area  |  Determine Number of Plants  |  More Information


Start by Finding the Area of the Planting Bed

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. 

Use this article to learn how to calculate the area of your planting bed, regardless of its shape: How do I determine the size of my garden bed or lawn in square feet?

Websites and phone apps are also available to determine the area of your garden bed or yard using online maps.  One example is this site: Measure My Lawn.

Multiply the Area by the Plants Needed per Square Foot

Once the total area has been determined, the chart below can be used to determine how many plants are needed for the planting bed.

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, break the planting bed into smaller shapes - one for each plant species. Find the area of each plant grouping and determine plant numbers using the chart below.  

Multiply the Square Footage of the Planting Bed by the Number of Plants Needed per Square Foot to Get Plant Quantity
Recommended SpacingNumber of Plants per Square Foot
4 inches9
5 inches5.76
6 inches4
8 inches2.25
10 inches1.44
12 inches (1 foot)1
14 inches0.74
15 inches0.64
16 inches0.56
18 inches (1.5 feet)0.44
20 inches0.36
24 inches (2 feet)0.25
30 inches (2.5 feet)0.16
36 inches (3 feet)0.11
42 inches (3.5 feet)0.08
48 inches (4 feet)0.06

Example: You are planting daylilies 15 inches apart in a 28-square-foot planting area. This space would require 18 plants to fill it in properly.  (28 × 0.67 = 17.92; rounded to 18)


More Information


Photo credit: Paul Maguire/AdobeStock

Authors:
Last reviewed:
February 2025