Selecting the right creeping plant
Looking to fill those spaces between stepping stones or pavers? It's never too late to get a low-growing, creeping perennial plant to fill the gaps!
There are many tough little perennial plants, ranging in height from a 1/4 of an inch to 3 inches or so, that are perfect for use between stepping stones and pavers. These low-growing and spreading plants not only provide soil cover they also prohibit weed growth, prevent soil erosion, and provide tremendous aesthetic value.
Things to consider...
Before you rush out to buy your creeping perennials to fill those gaps, you need to make an assessment of where you’ll plant them. Match the plant to the environment by answering the follow questions:
How much foot traffic? - Not all creeping perennials will handle lots of foot traffic. The rule of thumb is this: The more delicate the leaf structure, the less traffic they’ll be able to withstand. Plants such as Dwarf Mondo Grass (pictured top right) will tolerate more foot traffic than Sedums. Will your stone or paver path, walkway, or patio will be walked on several times a day, once a day, or just once a week?
How much sunlight? - Make sure when selecting a creeping perennial that you match the plant with the amount of sun exposure in the planting area. Does the area receive full or mostly direct sun, morning sun with afternoon shade, morning shade with afternoon sun, or shade or mostly shade? There are creeping plants for any amount of sunlight or lack thereof.
How is the soil drainage? - Is the site well-drained, does it stay damp, or is it constantly soggy? There are creeping plants that will adapt to any level of soil moisture. Some creeping perennials, such as Blue Star Creeper, Golden Creeping Jenny (pictured right) and Mazus prefer or will tolerate consistently moist or damp soil. Others, such as Sedums (Stonecrop) and Creeping Thyme prefer a more well-drained soil.
Mixing it up - Some folks like continuity or uniformity and will use only one variety of creeping plant to fill all the gaps in their stone or paver path or patio. There's absolutely nothing wrong with doing so. But I like mixing things up (as pictured right)...and there are advantages to doing so. For one thing, I like the more natural or wild look...as if the plants blew in with the wind. Also, if you plant several varieties and one variety doesn't like the environment and looks sickly all the time or dies you haven't lost everything. You can then just replace the few unhappy plants with some of the ones that are happy in the environment!
See my favorite creeping perennial plants on Page 2 of this article
Planting creeping perennial plants
Consider space between stones
Space between stepping stones and pavers will vary with the type of path. Sometimes there's only an inch or two space between stones or pavers used in walkways, paths or patios, while on others, such as a more natural woodland path, there may be as much as 6-12" between stones. If you plant a wide spreading plant in a pathway that provides only narrow spaces between the stones, the plants will quickly cover the stones or you'll need to do more trimming to keep the plants in bounds. In narrow spaces use slower spreading plants such as Mondo Grass or Blue star Creeper. Fast growing and wide spreading plants, such as Creeping Jenny and Creeping Wire Vine are best for the wider spaces.
Planting your creeping perennials
When planting your creeping perennials, plant a full plant in wider spaces for faster “fill-in”. In small spaces, many creeping plants such as Blue Star Creeper (pictured bottom right) and Dwarf Mondo Grass, which spread by underground roots (stolons, rhizomes), can be divided by using a utility knife to cut the root ball of the plant into halves or quarters. 
Note: Plants with a single main stem cannot be divided!
If the gap you are wanting to fill between stones or pavers is narrow and tight try slicing long slender pieces to tuck in. If your existing path needs more space, you can chisel out some of the original path to create more of a gap for your plants. If necessary, add soil amendment to dense or compacted native soil to condition it.
