HG: Homrgrown Column September 27, 2008
Hi. We are putting in a flagstone walkway (in Eckert) and want to grow something between the stones that will withstand foot traffic. Do you have any suggestions?
If so, what type of soil, watering needs and what is the best way to plant? Can we get the seed and start our own in pots or should we start with small plants? We have looked at thyme and Irish moss.
Any suggestions will be appreciated.
Growing plants in the joints of a flagstone walk or patio is a great way to add texture, interest and even fragrance to the garden.
But before you plant, there are a couple of things to take care of.
First, you want to leave the grade of the “soil” between the stones a bit low, I’d say about 1/2 to 3/4 inch. This will give the plant some protection from foot traffic. If it’s level with the stones, it can expose the plant to crushing injury if traffic is frequent, besides making it difficult to water.
Just be sure you don’t leave the grade too low or it can become a tripping hazard. It’s also helpful to dig that “soil” up a bit before planting. I use the quotation marks around soil because you’re usually dealing with compacted sand and soil from installing the flagstones. Loosening that soil and mixing in some potting soil or compost will help your plants grow much better.
There are a number of plants you can use, and you’ve identified two of the common ones.
Wooly thyme is tough, pretty drought-tolerant, grows low and provides a pleasant fragrance when stepped on.
Irish moss is a beautiful dark green, but I think it may be happiest with a bit of shade in the afternoon.
In addition to these, look at Turkish Veronica, ##### toes, moneywort, creeping potentilla and mat daisy for sun, ajuga and some violets for shade.
Your choice will depend a bit on how much variety you’d like, as well as how tall you want the plants to grow.
Sometimes, you’ll see recommendations for sedum and ice plant. Both of these low-growing ground covers are super-tough and quite drought-tolerant, but their succulent leaves crush badly when stepped on. If you want to use them, you’ll need to provide ample “head room” for them to grow and survive below the surface of the flagstone.
One last thing is maintenance. These plants are spreading ground covers, so they will often grow out over the surface of the flagstone.
Unless there’s frequent foot traffic to hold them back, you’ll have to trim them once or twice a year to keep them from completely covering the flagstone.