Winter sowing is a fun and easy way to start seeds outside during the winter. Seeds are sown in miniature greenhouses made from recycled plastic containers, and then put outside in the snow and freezing cold. … Once the weather starts to warm in the spring, the seeds will germinate at their own pace, just as in nature.
It is great for any seeds that require cold stratification to start them off. The method can also be used in early spring to start off annuals and perennials that you would usually do under cover or any you wish to have more control over than you do with broadcast sowing.
Preparing a milk bottle for winter sowing
- Wash out the bottle and make holes in the base. (Warm a skewer in a flame, use a soldering iron or push scissors etc through- the latter is easier if the bottle is warm.
- Write the name of the plant on the outside of the bottle -near the base is best as you may be removing the top later on. (Sharpie, Paint pen or similar is best to be weather proof.
- Cut around the bottle below the handle leaving a few centimetres to act as a hinge
- Fill the bottle with a multi-purpose or seed compost
- Stand the bottle in a tray of water until the surface of the compost is moist
- Sow seeds according to packet instructions e.g. some need to be covered and others must remain on the surface of the growing medium.
- Water gently from the top with a can with a rose if required.
- Put a name label in as back-up in case of fading of outer writing
- Tape the bottle back-up.
- Do NOT replace the lid
- Stand outside in a semi-shaded location.
- In very dry weather, you may need to stand the bottles in a tray of water from time to time but usually the combination of condensation and rain will keep them watered for you.
Your resulting baby plants can be pricked out conventionally or grown on in the bottles and then cut into “hunks” and planted out!