The Small Willy the Worm Water Sensor is a practical terracotta tool designed to help gardeners maintain optimal soil moisture. Standing 10cm tall, Willy changes colour—from dark when soil is moist to light as it dries—offering a clear visual cue to water plants promptly. Ideal for monitoring flower beds and vegetable patches, these durable, easy-to-use sensors, making it simple to keep your garden thriving with consistent watering.