How Many Groundcover Plants Will You Need?
This needn’t be a difficult decision. Let me tell you how I figure it out before I ever head to the nursery.
Step One…
I figure out how many square feet I’ll be planting. For square and rectangular beds it’s a matter of merely multiplying length times width, and the product is the number of square feet.
For oddly-shaped curvilinear beds you try to assign general rectangles within the beds to approximate the sizes of the various areas and you allow just a little bit extra in case. It’s always better to have a few plants too many than to run short.
Step Two…
I decide on which groundcover I want to use. Some are larger as they mature or they grow very rapidly. With those I’m more tempted to plant somewhat larger plants (1-gallon pots) and to space them a little bit farther apart.
This list might include low shrubs such as Flirt or Harbour Dwarf nandinas or trailing rosemary, and it might include robust sprawling vines such as Confederate star jasmine, purple wintercreeper euonymus or even Carolina jessamine when they’re used as groundcovers. Giant liriope might fit here as well.
Some stay quite small or are slower to fill in. With those, I’ll often choose smaller plants (4-inch pots or fist-sized clumps) and plant them closer together.
This list would include, at least in my landscaping, dwarf and regular mondograss (“monkeygrass”), ajuga, English ivy, Asian jasmine and perhaps it could also include purple wintercreeper.
Step Three…
Based on the choices I’ve made from the information above, I’d quickly be able to figure how many plants to buy using these figures from Page 143 of Neil Sperry’s Lone Star Gardening.
Calculating how many plants to buy
Once you have measured the bed and figured the square feet involved, multiply that number times the plants-per-square-foot in this chart to determine the number of plants you should buy. It’s wise to buy 15 percent more to fill the odd corners.
Spacing of Plants (inches) | Plants per Square Foot |
8 by 8 | 2.25 |
10 by 10 | 1.44 |
12 by 12 | 1.00 |
15 by 15 | .64 |
18 by 18 | .44 |
20 by 20 | .36 |
24 by 24 | .25 |