Hemp mat / Square moisture pad

Placed on top of the food scraps in the top tray, the square hemp mat keeps the surface moist while letting air circulate, so your worms feel as if they were just below the soil surface. It also helps keep fruit flies away from fresh scraps.

The square mat isn't a must-have accessory: brown cardboard or an old cotton T-shirt will do the job too. Our mat is dense (29.5 oz/yd², or 1,000 g/m²), natural, and made in France. It's also included in the 5-accessory pack (two mats, in the shape of your choice).

All our tips: Which accessories do you need for your worm composter?

Yes! On a TinyWorm, a WORMcube, a Lombribox, or a City Worms, the square hemp mat recreates the cool, moist conditions of the soil surface: your worms come up to shelter under it and feed on the fresh food scraps placed beneath it.

They also love to breed there: you'll find cocoons about the size of a grain of rice, pearly at first and then yellow. The square mat helps stabilize the temperature in these compact models, and since it's made of 100% natural hemp, your worms will eventually nibble it away too.

Place the square hemp mat directly on top of the worms, in the active tray, under the lid. Each time you feed, lift it up, put the food scraps and cardboard underneath, then lay it back down: it's a blanket, never a surface for food.

Don't water it before setting it in place: laid down dry, it gradually absorbs moisture from the food scraps. The only thing you can add is an occasional spray of diluted WORMboost, directly onto the mat, to boost your worms' activity.

The square hemp mat moves up with the food: as soon as you add a tray to your WORMcube, City Worms, or TinyWorm, place the square mat in that new top tray, which becomes the active tray. Don't empty the old tray: it stays underneath and gradually turns into vermicompost.

A single mat is all you need, and it won't get in the way of the worms as they move up toward the fresh food scraps. If it's already very full of holes, leave it in the old tray, where the worms will finish eating it, and lay a new square on top.

All our tips: How does a stacking-tray worm composter work?

A square mat lasts about 2 to 3 months. The worms eat it little by little: once it's full of holes and well chewed through, it's time to put in a new one.

Don't throw the old one away: it may contain cocoons. Lay the new mat on top, or mix the crumbled remains into the food scraps in the active tray, where they'll serve as carbon-rich material. That means a pack of 5 mats gives you 10 to 15 months of use in your small worm composter.