Sow perennial and hardy annual seeds to place outside during the winter. Some seeds need the cold to germinate and others just tolerate the cold until they are ready to wake up. No indoor lights required. No hardening off of tender seedlings. Each jug is a personal green house that provides a safe growing environment until hot weather dictates it is time to remove the protective hinged lid. Plants can be potted up later into bigger pots or planted directly into the garden. Tomatoes, nasturtium, lettuce, any perennial... these and others are excellent candidates for Milk Jug Winter Sowing.
Milk jugs in half gallon and gallon size are ideal, as they are easily punctured and cut with sharp scissors. Drainage holes in the bottom are critical to allow excess water from rain or exuberant watering to drain out. It is easier to puncture them now before cutting the hinged lid.
If using clear plastic juice jugs, the thicker plastic requires a heated poker to make holes.
It is good to poke a hole at the highest point of the base, as otherwise the roots might sit in a puddle and cause root rot.
These holes have been circled with a black marker pen to highlight them. As long as the soilless mix does not spill out, you really cannot have too many holes. If the variety being planted needs dry soil or especially good drainage, then twist the scissors to widen the slits.
Next cut the hinged lid. The bottom section is the pot and the top is the green house portion.
Scissors work on milk jugs and plastic juice jugs.
Sterile "soil" is needed at this baby stage of growth. Damping off disease caused by fungus is the bane of all who start their own seeds. Too wet and fungus will grow. Too dry and the plants can struggle or die. Good drainage and sterile mix are the best defense against this problem.
This big compressed bale it way too much for most people. Any nursery or hardware store will sell smaller bags of germination mix. This one has sphagnum peat moss, vermiculite and perlite. Coir works too.
Adding water to a big pot of mix works well.
Treat the soil mix gently. Overmixing can compress the fibers. Try to avoid touching hands to the mix. Use spoons and other clean tools to stir the mix until the pale color turns darker indicating it is damp.
Scoop mix into base of milk jug.
Rain and snow gets into the open lids, so the seeds stay moist as they get light and dark, cold and warm. No need to worry even if there is an arctic blast dropping temperatures below zero. The only time to worry about them is in April and May when we sometimes have strange hot droughty weather that might "cook" seedlings. Water and flap back hinged tops as needed throughout spring. Tender perennials and annuals can be added throughout April and May, as a cold spell at that time of year is unlikely to kill a dormant seed. They really do "wake up" when the night temperatures, daylight hours and temperatures suit them. The seedlings might not be early, but they are tough from the get go. By Memorial Day all lids should be cut off, and many perhaps cut off in April. Protect the seedlings from rabbits and deer at this point. Hardware cloth or sticks woven into cloches (protective covers) can work well. Will you try this technique yourself and share your spare seedlings with the Carlisle Garden Club for their Saturday May 18 Plant Sale?