Much has changed in my neighbourhood’s front gardens. When I first came here more than 25 years ago, many had a combination of overgrown junipers and white birch trees. Now, there’s a much broader selection of ornamental conifers and many interesting trees, including tan-pink river birch, purple beech, ornamental cherries, redbuds and dogwoods. But nothing has surprised and delighted me more than the thyme lawn I discovered this weekend.
Thyme has long been a groundcover solution in hot and dry soil locations, but seldom seen as a lawn planting in our cold climate. We use various species of thyme to fill in between plants or to cascade around rocks, but I’ve never seen a true thyme lawn until now. With only a few exceptions, many thyme species are hardy to Zone 6, leaving them perilously close to their frost hardiness limit in my Zone 6a neighbourhood. Thyme plants are often damaged when snow and ice lay over them for several winter months, causing patchy emergence in spring, and requiring replacements to fill the holes. But the thyme lawn I recently saw (in beautiful mauve bloom) has come through just fine, and after a close look, I’ve considered how this was achieved.
My first thought is that we’ve had several consecutively warm winters. I don’t keep track of daily high and low winter temperatures, but I certainly haven’t been wearing my heaviest Nordic sweaters. Even just one degree warmer makes a difference to plant survival in cold climates, and perhaps that has favoured resilience in thyme plants.
My second thought is that correct soil preparation makes a big difference to the vigour of plants with specific soil requirements. Thyme definitely likes sandy and free-draining soil, low nitrogen and maximum sunlight. I’ve been growing thyme in the rich, moist soil of my garden beds, and piling snow from the walkways over it in winter. Was there ever a more disastrous scenario for thyme plants?
The thyme lawn on my road is planted in the front section of lawn abutting the street (the hottest and driest section), and taking up approximately a third of the lawn area. (Space behind the thyme is given over to a huge shrub rose surrounded with yet another lawn of low-growing sedums.) Being basically shameless, I took a moment to explore the soil under the lush carpet of my unknown neighbour’s thyme lawn and found a tough and gritty soil that had been supplied for the location. The combination of warmer winter temperatures and a hot summer location with steep drainage perhaps has resulted in this lovely thyme planting that has made a consistently thick coverage.
The best species for a thyme lawn are the creeping, mat-forming varieties, such as mother-of-thyme (Thymus serpyllum pulegioides, Zone 3) or red creeping thyme (T. serpyllum praecox Coccineus Group, Zone 3). The world of thyme species is large and you might come across other low creeping plants to experiment with. With a hardy variety and a hot, dry, well-drained location, maybe it’s time to establish a thriving lawn or broad strip of beautiful thyme.