I have a steep driveway that isn't very practical for parking in, but looks pretty nice. It is "paved" with bricks and large marble slabs, with dirt in between the stones. Although this looks pretty nice and rustic in the winter/spring, but it gets out of control with weeds come summer.
Does anyone have any suggestions for a good, low ground cover that will grow well in this environment? It would be great to have something to block the weeds and provide some year-round color between the stones.
Creeping thyme (Thymus serpyllum) works very well for me in USDA zone 4. Tolerates a lot of traffic, small flowers, turns a reddish colour in a mild winter. It is readily available at most nursery centres and once it gets established will self seed.
The downsides are that the flowers attracts bees which may not be what you want when you open your car door. It is vigorous enough to cover the bricks and slabs so you will have to cut it back yearly. It grows thickly but grass seeds can germinate so if you have an adjacent lawn which you cut with a power mower you may end up weeding between the cracks.
I would use polymeric sand. It is expensive but when properly applied provides a weed proof barrier that allows water to move through it. As one paving installer said to me "Once you use it you'll never go back".
