I have a bed thats 12x4 feet with pvc hoops, intended for starting seeds of perennial plants, and holding containerized plants. I want it to function like a cold frame, but have a plastic top for protection from hard rains. I tried row cover fabric but that seems to let in too much rain, the plug trays I used fill up with water, some small seeds wash out presumably, and then the soil compacts. Now I want to switch to plastic but I dont want to bake my seedlings. If the ends of the tunnel are completely open will that provide enough ventilation? Would you recommend full length side vents or ridge vents too? I dont want it to be warm in the winter time either, dormant plants need to stay dormant, and seeds need to stratify. Thanks
