Plant Calculator

If you have Javascript enabled in your browser... (how do I do that?)
you can use this tool to calculate the number of plants required to cover an area with a certain space between plants.

If you do not have Javascript enabled in your browser...
and you need help figuring out how to use this page to determine how many plants you need, see "How Many Plants Do I Need?" which explains this page in detail.

General Spacing Recommendations - Most Groundcovers

If there is no spacing suggestion in the description of the product, use these suggested spacings to generally get good coverage within one year (if you want it to fill in faster, use the smaller spacing). Note: hostas have no suggested spacing because their use is subjective: they are used as single accents, in rows or mass plantings; the spacing depends on how you plan to use them.

Spacing Multipliers

You can use the following formula to calculate how many plants you will need based on your "Spacing Multiplier".

Example: you want to cover an area of 120 square feet with a spacing of 10". The Spacing Multiplier for 10" spacing is 1.45. Multiply 1.45 x 120 and you get 174 plants needed.

Formulas for figuring square feet

Squares and rectangles - Length x width
Circle - 3.14 x radius squared

Hardiness Zone Map

• Hardiness zones are a general indication of cold hardiness and are not exact. Elevation and other factors may affect suitability of certain plants, we suggest that you consult your local cooperative extension or a local landscaper or garden center if you are on a fringe zone.
• Recommendations for sun and shade planting are included to help you choose plants for your specific location. In the south, some plants listed as full sun can be more difficult to establish than in cooler climates. Heat, rainfall and other climatic differences can affect young plants.

Equivalents

1 sq. yard = 9 sq. ft.
1 sq. ft. = 0.11 sq. yds.
1 sq. ft. = 144 sq. inches
1 acre = 43,560 sq. ft.
1 acre = 4,840 sq. yds.

1 cu. yd = 27 cu.ft or 22 bu.
1 cu. ft. = 4/5 bu.
1 1/4 cu. ft. = 1 bu.
1 cu. yd. = a 3 inch layer over 108 sq. ft.

1 cu. yd. will fill:

• 190 1 gal. cans
  
• 1225 4" pots
  
• 3000 2 1/4" pots
  

Till the top 12" of the area where plants are to be grown. The best way to improve soil is to add organic matter such as peat, compost or manure at a rate of 25% by volume into the planting area.

Incorporate a complete fertilizer like 10-10-10 into the soil at the time of planting. For maximum growth, a high nitrogen fertilizer like 16-4-8 should be applied every 4-6 weeks after planting, beginning in early spring through late summer. In early fall and winter, apply 5-10-15 at recommended rate.

For best results, incorporate a pre-emergent weed control herbicide into the planting area. Follow label instructions for the brand you choose. Be sure to check the label of the brand selected to assure applicability to the specific groundcover to be treated. Applying a heavy top mulch will greatly assist weed prevention and control and increase moisture retention.

If you'd like to reduce your frequency of watering and risk of drought damage, consider adding Horticultural Grade Terra-Sorb (AKA Super-sorb) to your soil. It absorbs up to 200 times its weight in water and slowly releases it. It's non-toxic, non-hazardous to the environment, and compatible with fertilizer (see Terra-sorb's Material Safety Data Sheet and Product Directions). Apply at a rate of 1 pound per 100 square feet for each 2 inches of depth by raking or tilling into the ground 2-4 inches (or mix 1/2 teaspoon into the soil under/around each individual plant).

Terra-Sorb is available at many garden supply stores and online in quantities ranging from 3 ounces to 40 pounds

Planting Instructions

The best times to plant are spring and fall, when soil is workable and out of danger of frost. Fall plantings have the advantage that roots can develop and not have to compete with developing top growth as in the spring. Spring is more desirable for perennials that dislike wet conditions or for colder areas, allowing full establishment before first winter.

To plant container-grown plants: Prepare planting holes with appropriate depth and space between. Water the plant thoroughly and let the excess water drain before carefully removing from the container. Carefully loosen the root ball and place the plant in the hole, working soil around the roots as you fill. If the plant is root bound, separate roots with fingers. Continue filling in soil and water thoroughly, ideally protecting from direct sun until stable (if possible).

To plant bare-root plants: Plant as soon as possible after delivery. Prepare suitable planting holes, spread roots and work soil among roots as you fill in. Water well and ideally protect from direct sun until stable (if possible).