Which types of containers can be used to start seedlings indoors?

Question:

Which types of containers can be used to start seedlings indoors?

Answer:

Various containers can be used to germinate and grow transplants.  Gardeners can purchase flats, trays, cell packs, pots, compressed peat pellets, and other commercial products.  Cut-off milk cartons or plastic jugs, paper cups, and egg cartons can also be used to start seeds.  Previously used flats, trays, and pots should be cleaned and disinfected before use.  Wash the containers in soapy water, then disinfect them in a solution of one part chlorine bleach and nine parts water.  Holes should be punched in the bottom of milk cartons, jugs, paper cups, and similar containers to allow for drainage.