I use clear plastic bread wrappers, just the right size for a square four inch pot you have so many of. I prefer to start Hydrangeas in one gallon pots because they start so fast and this avoids a transplant. For a one gallon pot I use produce clear plastic bag. Some bags are worthless which influences where I buy produce. Al

Ah, bread bags. I never thought of those. Thanks. Most of the produce bags at my Kroger are either green translucent or white translucent.