When to Mow Creeping Thyme Lawns Creeping thyme lawns are a beautiful and low-maintenance alternative to traditional grass lawns. They are also very drought-tolerant, making them an excellent choice for water-scarce areas. While creeping thyme lawns do not require regular mowing, it is a good idea to mow them once or twice a year to keep them looking their best and to encourage new growth. The best time to mow creeping thyme is in the spring, after the last frost, and again in the fall, after th