By Katie Drewitz
University of Minnesota
Extension
Has the end of January fog and the rollercoaster temperatures we’ve been having have you dreaming of spring? While it is still too early to start seeds indoors, there are a few things you can do to stretch your green thumb. Several people recently have made inquiries about winter sowing, which can be a great way to start early seeds.
Winter sowing kits consist of using recycled containers such as milk jugs or pop bottles and turning them into “mini” greenhouses.
The steps to construct a winter sowing kit include:
1) Clean desired tall, large, plastic recyclables such as milk jugs or 2-liter pop bottles.
2) Carefully cut the container, leaving at least three inches on the bottom half for potting soil, and a small portion of the plastic intact to act as a hinge.
3) Cut or punch holes in the bottom of the container for drainage; discard jug cap to provide air movement and allow moisture in.
4) Place a minimum of three inches of clean, sterile potting soil in the container.
5) Water the soil, and let drain.
6) Sow seeds at appropriate depth according to seed packets.
7) Good seed options include vegetables such as lettuce, kale, radishes, and kohlrabi, or annual flowers such as alyssum, pansies, and viola, or hardy perennials that need a “chilling” period to germinate such as Echinacea, flax, and yarrow.
8) Lightly water seeds in.
9) Label your container with a plant marker on the inside or on the bottom of the container; be aware that even permanent marker will fade and may need to be reapplied.
10) Close and tape container shut; heavy duty, clear duct tape is a nice option.
11) Place winter sowing kits outside in a sunny location.
12) Monitor for moisture, temperature, and growth.
13) Remove tape and open container once temperatures have warmed and/or plants have outgrown space.
a. Due to fluctuating spring temperatures, tape may need to be removed and lid partially or completely opened during warm days and closed again for cool nights.
14) Transplant to desired garden or container once temperatures and permanent site are prepared.
Winter sowing can be a great way to get a jump start on spring, and start some plants in your own mini greenhouse. If you have questions about this or any other agriculture, horticulture, or natural resource topics please reach out to your local Extension educator. Residents in Fillmore and Houston counties can call (507) 765-3896 or (507) 725-5807.