Thymus fragrantissimus. Grow this distinctly orange-scented thyme in hanging baskets or rock gardens and it will cascade over the edge. Its trailing nature makes it a prime candidate for ground cover, and established plants can even stand up to light foot traffic. Orangelo Thyme is hardy to Zone 5 and evergreen. It will grow between paving stones and over slopes and other hard-to-cover areas. And of course it is edible — its citrus overtones blend perfectly in savoury dishes. It reaches a maximum height of 25-30cm (10-12").