Abstract: A stackable raising seedling device has a device body and a floating planting board. The device body has raising seeding hole parts disposed at intervals and holes disposed intervals. The raising seeding hole pans and the holes are staggered in parallel and with each other along a first direction, the raising seeding hole part and the holes are staggered in parallel with each other along a second direction, and the holes of the first direction and the raising seeding hole parts of the second direction are adjacently arranged. The raising seeding hole pan can receive a culture medium layer, the culture medium layer has an agar gel, and the agar gel is composed of a plant growth nutrient, agar powder and water. The present disclosure improves the overall seed germination rate and the quality of planted crops when massively planting the planted crops.

Abstract: The present disclosure relates to a culture medium having an agar gel forming by at least one plant growth nutrient, agar powder and water, wherein the agar gel is 100 wt %. A culture medium manufacturing method, a culture medium structure and a culture medium structure usage method are also illustrated in the present disclosure. The culture medium structure has a culture medium of the above culture medium, a seeding board for receiving the culture medium layer, wherein the seeding board has a hollow body which has a top hole, a bottom hole opposite to the top hole and a top base disposed on a top peripheral of the hollow body, and the hollow body and the top base are integrally formed. Via the culture medium of the solid agar gel having the plant growth nutrient, growth health and quality of crops are enhanced.