I am not a milk drinker so I use soda bottles for wintersowing. I like being able to see the plants inside without lifting the top. I have some of the plastic trays that fit 8 bottles per tray so they are easy to move around.
Are there any types of seeds that can be fall sown? I store my potting mix in lined garbage cans outside. Last year I had to bring them in to defrost! I may fill my containers in advance once the black walnut trees are done messing up my patio with leaves, branches and nuts. It hurts when those darn nuts hit you in the head. Poor Winston the pug is sleeping under the desk at my feet. He doesn't mind thunderstorms, but he is concerned when walnuts hit the roof. He wakes up and checks to be sure the sky isn't falling.
