Seed It Microgreen Grow Mats. 3 mats per pack. Made from 100% British hemp fibre, hemp mats are one of the most sustainable growing mediums you can get. Grow a steady supply of microgreens and cut-come-again salads — from home. Perfect for growing micro herbs on your windowsill. Boost your nutrient intake and spice up your meals with flavoursome homegrown micro greens. The Seed It Grow Mat allows you to quickly and cleanly grow healthy, fresh food from the comfort of your own home. Avoid plastics, pesticides… and the supermarket!