We are often asked how to overwinter plants in our containers. Overwintering is easier than you think, and is a great return on investment since you don't have to replant those crops in the spring. This post will address some commonly asked questions and most of these tips will apply to a wide variety of crops including strawberries, perennial herbs and hardy cool weather vegetables like kale. Follow the tips below to give your plants the best shot at surviving the cold winter months.
Choose plant varieties that are hardy in your area.
This is the most important thing to keep in mind. If you're trying to overwinter basil outside in zone 5 you will be disappointed. Find your garden zone and choose plants that are at least your zone or lower. For example, we are in zone 7 which means that a plant is perennial in our area if it's also a zone 7. We get to around 0 degrees F where we are. If we plant something that's a zone 5-8 then it has an excellent chance of surviving the winter in containers because it's hardy in zone 5 (which is hardy to -20 degrees F!).
All of that to say, be choosy about varieties you want to overwinter and save for the following year. Check plant tags and seed packets before planting and make note of what's going to work best in your area. Make sure you do plenty of research before you buy any plants too. It might also be helpful for you to check out some reviews on somewhere like online garden centres to see what previous buyers think! It pays to do your research so don't rush into buying anything.
Be aware of moisture levels.
Plants can dry out even in the winter. I don't know about you, but when Thanksgiving and Christmas rolls around the last thing on my mind is watering. If your planter isn't frozen solid, then check every couple of weeks for water. You may need to water even in cold temperatures. Sometimes our winters are warm and rainy and sometimes we get very little precipitation. But either way, it's a good idea to check up on your plants through the winter season to make sure the soil doesn't dry out completely. Lets not forget about the intensely hot summers that can come about. Weather around you gets so hot that your pond dries out then you will need cooling solutions for your Almost Black water lily and other plants that you put in your pond.
Resist pruning during hard frosts.
Strawberries will go dormant in winter and they will look completely dead, but it doesn't mean they won't come back in the spring. It can be so tempting to want to prune/cut back your plants in the winter months. Don't do it. When overwintering container gardens, your goal is to put them through the least amount of shock possible.
Move your planter to a protected area.
Do you get really cold, windy winters? If you do, move your planter (preferably with the Mover) close to your house, near a shed or railing, or really anywhere that will provide more protection for your garden. It's amazing how much heat your home will give off in the winter. That heat will help keep your plants insulated during cold nights.
Use a frost net cover.
If you're in a cold climate or if you are in a warmer climate with random frosts, the frost net cover is a great option for keeping your plants protected. It allows some wind, sun, and water through so you don't have to remove it during the day unless it gets really warm. It will protect down to 26 degrees. The cover is a nice option for hardy annuals like kale and cabbage. It will give them just a little bit of protection from really cold days and nights in the winter.
What are your tips for keeping your plants healthy through the winter months? Let us know in the comments below.