Pots Winter Winter Protection

How to Overwinter Containers on a Balcony?

Urban gardening has its challenges. When fall comes knocking, how do you store decorative containers for the winter? Where to settle all these pots, when you don’t have decent storage space? And the substrate? What do we do with the potting soil?

Autumn is approaching, it’s time to close the garden… and put away your pots. Photo: Pikist

Proceed BEFORE Frost!

The most helpful tip I can share with you is don’t wait until frost arrives to start emptying pots of their plants and substrate. As soon as the temperatures oscillate between 44 and 50 F (7 and 10 Celsius), begin the preparation. Annual plants are sent to compost. Plants that have the potential to survive indoors are repotted. As for potting soil, it’s good to know that it can be reused a couple of years. But when it gets too dry and doesn’t retain humidity anymore, it can also be dropped in the compost bin

Plastic or Ceramic?

If the plants are grown in plastic pots or in fabric or geotextile pots, good news! The potting soil can remain in these containers all winter. There is little chance that the container will break, unless the pots are of lower quality. However, if the pots are terracotta or ceramic, the substrate must be removed completely. Our concern here is frost. In fact, under the effect of intense cold, the water contained in the pores of the potting soil expands. The volume increases and that’s what makes the pots burst. A pot rarely survives a winter if the substrate is left in the container. But, properly stored, these pots can last for several decades.

How to Empty Pots to Prepare Them for Winter?

It’s all good to completely empty our pretty fragile containers, but what do we do with the potting soil? The basic principle is to temporarily store this potting soil in a large plastic bin. For the ingenious recyclers that we are, it is possible to use large plastic pots of 7 gallons or more, left over from the tree plantation.

These black plastic pots are quite easy to find and are perfect for storing potting soil from terracotta and ceramic containers. Photo: Pixabay

Finally, the plastic pots already present and freed from dead plants can also accommodate a few handfuls of extra potting soil. If you opt for buckets or pails, you will need to drill holes to ensure the drainage of rainwater and melting snow. These pots of substrate can be stacked in a corner.

A pot and its substrate. Separate the inseparables, for a moment, in winter. Photo: Julie Boudreau

Play Russian Doll

When all the pots are empty, place them upside down and insert them into each other, a bit like Russian dolls. The important thing is to make sure there is good clearance between each nested pot. If it’s too tight, it’s better to make another pile. The entire work is then packed in a corner of the patio. If the patio is at altitude, try to place your pots in the least windy place on the balcony. Plastic pots and substrate pots will also be stacked in this corner.

Secure the Tarp!

Cover this beautiful stack with a good waterproof canvas. Plastic tarps used for moving are perfect for sheltering these containers. This canvas must be securely attached, around the pots, but also to the balcony railing. In high winds, it’s the first thing that will want to take off!

All the pots, tidy and ready to be covered with a tarpaulin for winter. Photo Julie Boudreau

And there you have it, everything is ready! Keep an occasional eye on this installation, to ensure that the tarpaulin is in place. Snow can accumulate without fear on this pile. Then in spring, when the snow and ice have disappeared, remove the tarpaulin, fill the pots and wait for spring!

Note: The challenges of overwintering pots concern regions with cold winters (USDA zones 2 to 6).

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Julie Boudreau is a horticulturist who trained at the Institut de technologie agroalimentaire in Saint-Hyacinthe, Québec. She’s been working with plants for more than 25 years. She has published many gardening books and hosted various radio and television shows. She now teaches horticulture at the Centre de formation horticole of Laval. A great gardening enthusiast, she’s devoted to promoting gardening, garden design, botany and ecology in every form. Born a fan of organic gardening, she’s curious and cultivates a passion for all that can be eaten. Julie Boudreau is “epicurious” and also fascinated by Latin names.

2 comments on “How to Overwinter Containers on a Balcony?

  1. Mij Convery

    Russian doll the pots right side up, sliding lengths of bamboo sticks – 2 per pot – on opposite sides to guarantee the pots don’t wedge together. Cluster stacked pots in a deck or patio corner & neatly drape & fold sides & bottom of tarp. Tie as Julie describes. This array will not shed snow as well but the inward angle of the tarped group will allow you to add bricks tucked in around the bottom edge of the tarp to defeat the wind.

  2. Good advice Julie. I have a couple of old rain barrels that cracked so all of my old potting soil goes in there alternating with leaves. Come Spring I do up my new pots with half of this soil, new soil and some compost. Works like a charm and saves me a fortune.

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