Whenever you planted ground cover, odds are you did one of two things wrong: Either you spaced the plants way out because that’s all you could afford (and then the weeds took over), or you packed them in really close, paying big bucks up front so they’d be done right now (but looking good just for a couple of days). No, spacing isn’t grid-like, or even numbers-only; it’s a matter of money or time. Unless you understand that, you can’t have both and you never will.
The chart above breaks this down visually by showing how coverage circles overlap at different distances. Guessing becomes a simple math equation. Until you learn garden geometry, most of us don’t think about it…until its too late. We look at those nursery pots full of plants…and forget that what we’re buying is a thing that spreads, merges and eventually creates a seamless carpet.
Simple Tips for Planting Ground Cover
There are typically just two approaches. First: Spacing at minima (the amount recommended by the label) mean immediate fullness. This is good if you have a high-profile area with a lot of eyes on it, say, an entranceway… Or just a small border. It works if you don’t mind having double or triple the number of plants to begin with and need instant coverage with no more bare ground showing. But for expansive areas such as lawns or massive hillside, that’s far more costly then usual.
Second, use maximum mature-width spacing. This means you start with fewer plant, but space them far enough apart so they will eventually meet up with time and mulch. This saves you big bucks up front (thirty to fifty percent cheaper per square foot); however, it also requires waiting patiently…and maintaining a tidy layer of mulch until things close up to cover their own bases.
Many people fail to do this. They assume that spacing only matters for looks, but in fact it determine how much work you will do maintaining it for years to come. Where you place things is important, but so is what you choose. Not all ground covers are equal: Some are fast-running thugs (give them space and they’ll be in your next-door neighbor’s turf). Vinca and ajuga is good examples. They propagate by underground stems, spreading fast and easy into shade beneath trees.
Others. Like Pachysandra, grow even slower, prefer deeper shade, and need to be planted closer together at first, since any bare spots may never fill in. For sun, there are species that like dry conditions (drought-tolerant) but require well-drained soil, such as Creeping Thyme or Sedum. These work best on slopes where erosion might be a problem because they hold the soil down with their shallow root mats.
The infographic also notes which are deer-resistant; if you are in an area where the local wild animals treat the garden like an all-you-can-eat buffet, this can be key. Fleshy succulents like sedums, or other aromatic-herb types like thyme tend to go ignored by deer, but leave hostas unguarded and they will be eaten to the ground in no time.
Or there’s this nifty little cheat to get maximum coverage while avoiding additional purchases: Forgo straight lines across your square grid when you plant, and instead stagger them into a triangle. Offset every other plant by half as much space again in the following row. By making this small geometric adjustment, you’ll have roughly fifteen percent more coverage with the same number of plants. It feels like cheating, really, it fills in all those diamond-shaped holes that always seem to remain in standard grid planting. It creates denser foliage and better weed suppression, too. You get all this just by moving your trowel a few inches to the right.
Any spacing plan hinges on preparation. Digging up the area eight inches deep loosens the soil; add compost if it’s heavy clay. Slow drainage is bad news: It slows the rate at which the new roots will spread and can stress them (especially in young plants). Even with the best of spacing plans, poor soil means no go. Be sure to water deeply two times a week during the initial month as they take root.
Once established, most of these varieties are amazingy low-maintenance. Why? They’re creating a living mulch that over time uses less water. After all, what makes any groundcover great isn’t always its individual beauty. It is also about how well it works together, looking good while using its texture to hold the earth in place.
Whether your strategy is short-term budget splurges or longer-lasting tactics, keep this in mind: Plants have a way of growing. So either let them breathe a little, or plant so many that they can out-compete each other. Whichever route you go, your garden will reward you, if only after that initial critical period of settling in.