Winter Container Gardening with Native Plants

As temperatures continue to drop, it's hard not to despair over your garden's withering plants and leafless trees. Here's a simple DIY project to keep your thumb green over winter while stocking up on seedlings for the spring.

Winter seed sowing is a great way to inexpensively grow native vegetation for planting in the Spring. While the following method works for most types of seeds, be sure the timing is right for the plant's growing season.

Materials

• Clear plastic water or milk containers

• Duct tape

• Potting soil

• Native plant seeds such as coneflower, aster, Joe Pye weed, black-eyed Susan, or milkweed

Pro Tip: Buy seeds from online sellers who specialize in native plants or gather seeds from your garden after cutting dead flowers.

• Perlite

• Water

Instructions

1. Remove the cap from a plastic container and discard the cap.

2. Puncture the bottom of the container a few times to provide drainage.

3. Cut the container in half so the container top opens like a hinge but is not separated from the bottom of the container. This creates a greenhouse effect for seeds that require cold stratification to grow.

4. Mix the potting soil and perlite so the mixture is about 30% perlite.

5. Fill the bottom of the container with about four inches of the soil and perlite mixture.

6. Place the seeds on top of the soil or as directed on the seed packet.

7. Water the seeds well.

8. Use duct tape to seal the top and bottom halves of the container together.

9. Optionally, cut a few additional holes in the sides of the container to let more condensation escape.

Starting in January, put the containers outside where snow and rain can reach the plants to provide the required moisture for growth. It is not unusual for your mini-greenhouses to be completely covered in snow for weeks—this is fine because the seed containers are well-insulated by the snow.

The goal of this process is to allow the seeds to grow in the mini-greenhouse until after the last frost in Spring, which eliminates the difficult process of "hardening off" young plants. This method also increases the germination rate for native plant seeds because native plant seeds are typically small and easily washed away by heavy rain or snow-melt.

As the weather gets warmer and the plants continue to grow, leave the tops of the containers open, especially if plants are growing too tall for their containers. Leave the containers open only if you are past frost dates, otherwise you risk losing the entire batch of plants. When you're ready to plant, cut off the top of the container and plant the best seedlings directly in the ground.◼

Laura Gessert is a contributing writer for The Grapevine. She also helps run Gessert Books, which specializes in self-published and university press books. For more information, check out http://www.gessertbooks.com/.