I’ve used paper towel, or toilet paper cardboard rolls for starting sunflower seeds. It’s important to bury the whole cardboard roll beneath the soil once transplanted or else it will wick moisture up from the garden bed and dry out the seedlings. Keep the cardboard tube w/seedling completely buried just underneath the soil by about 1/4 to 1/2-inch. The cardboard tube is perfect to keep seedlings nicely spaced in the garden. I loved making my own seedling pots.
I’ve used paper towel, or toilet paper cardboard rolls for starting sunflower seeds. It’s important to bury the whole cardboard roll beneath the soil once transplanted or else it will wick moisture up from the garden bed and dry out the seedlings. Keep the cardboard tube w/seedling completely buried just underneath the soil by about 1/4 to 1/2-inch. The cardboard tube is perfect to keep seedlings nicely spaced in the garden. I loved making my own seedling pots.