Always remember: Moss is a plant; thus, it cannot survive without water.
If you want to keep the glass opened, you need to water it more often. Although the moss is highly capable to keep the moisture underneath, you will soon find the agar starts to split. Do not worry, you can simply add a tap water to the glass and it’s already fine (see our video online for more instructions).
If you find it difficult to keep the plant moist, we recommend you to close the glass. Then the water cannot evaporate and will stay in the glass. However, airtight closing does not harm mosses, but limits CO2 for the photosynthesis hence lower fragrance. Therefore, give a little space for the best performance.
Low lighting is enough for mosses. Have you seen the mosses growing under the trees? Yes, it is the place they like to hang out. Mosses become stressed under the direct sunlight during the day, so a window facing east or north is the best, or a table with indirect sun. However, do not keep the moss in the complete dark longer than 5 days. Then the chloroplast will start degrading, which will make your moss look yellow.
What Not to Do: Please DO NOT release the plant to the environment if you care about the nature. The moss itself is not harmful, but is the right way to protect the nature without interference.