Keep your containers.
Free containers for your seedlings.
Seedling : A very young plant that has grown from a seed. (Cambridge dictionary)
Sowing time is upon us and what an haaaaaappy time for someone like me who hates winter. Doing seedlings make me happy because it brings me closer to my two favorite seasons, spring and summer. Seeing a seed grow and make a plant fascinates me every time - I've always found that magic - as does the opposite process (the plants giving us seeds after generously feeding us all summer long, seeds that will help start over new cycles of life a few months later).
You don't have to buy containers to start your seedlings, just look at what's hiding in your recycling bin. Personally, I much prefer containers that are not round, because round pots take up more space on your growing surface / in your greenhouse. I love the strawberry and also the cherry tomato containers, because they have a lid that serves as a mini greenhouse and once the sprouts come out, you just lift the lid off; maaaaagiiic! Orange juice containers also make good mini greenhouses; you cut the container at 3/4 on the horizontal, at the desired height. By not cutting it completely, it will make a greenhouse with a lid that holds in place, but which can be opened to take care of your seedlings. You can also use mushroom containers on which your will putt some plastic wrap over (or place in a plastic bag) until your sprouts come out of the ground. But it's less ecological. There are other containers such as yogurt and dessert cups, and you can also use milk containers and cut them to the desired height.
Two MANDATORY things to never forget when you use recycled containers: wash them properly before filling them with potting soil, and make holes in the bottom to allow excess water to drain.
Gardening is fun, but it's even more so if you can do it for free!