Help start your seeds growing regardless of season or temperature with the Greenhouse 10 x 20-inch Propagation Mat. The mat provides even bottom heat which encourages your seeds to germinate. The mat measures 10W x 20L inches and is a great accessory for your greenhouse. About Juliana America LLCJuliana has been manufacturing greenhouses for the past 40 years starting in Scandinavia. Making greenhouses that are designed to withstand the harsh weather conditions of Northern Europe Juliana is known for its quality. The largest distributor of greenhouses in the United States they also develop and manufactures greenhouse kits worldwide. Juliana added Juliana America in 1991.