JARS v64n4 - Freeze-proof Pots...A Good Thing

Freeze-proof Pots...A Good Thing
Merilee Mulvey
Florence, Oregon
Reprinted from the Macrophyllum January 2010 newsletter of the Siuslaw Chapter

I actually had time to read the paper several weeks ago and ran across an interesting article in the Register Guard Home ∧ Garden section, written by Sarah Robertson. It was titled "Freeze-proof pots." Yes, folks, it does freeze once in awhile here in balmy Florence, OR! There are many members who have beautiful terra cotta pots on their decks and patios. Let's see how we can protect them in winter.

Sarah talks about how most gardeners in harsher climates empty then clean and sanitize their pots before storing them away for the winter months. Here on the Oregon coast, many of our potted plants can overwinter outdoors but there is that occasional freeze that can burst a pot in no time. Some of us have pots with large shrubs or even small trees and there is no way we could empty those critters! So, the next best thing is winterizing the pots and Sarah tells us how.

Sarah says, "terra cotta pots have an insidious enemy: winter moisture." A freeze and thaw cycle which results in expansion and contraction of the clay, can weaken the pots. "Drainage is critical if terra-cotta planters are going to last more than a year. Water needs to drain from the pot and away from the pot if the clay is to stay relatively dry. All pots should be up on pot feet." After trimming the plant and adding a slow release fertilizer, if needed, then water if necessary.

Next, we need to wash the outsides of the pots thoroughly. Buy some bubble wrap (yes, the kind of rolls of bubble wrap used for packing). After drying the outside of the pot thoroughly, wrap the outside of the pot with a layer of bubble wrap. Make sure there is at least 3 to 6 inches [7.6–15.3 cm] of wrap above the side of the pot. Then tape the wrap securely and insulate the inside of the pot with cocoa hulls or shredded autumn leaves. This process will not only protect the pot, but also the plant growing inside of it. Other materials you can use in place of bubble wrap to insulate and protect pots is mulch or bales of hay held in place with plastic wrapping.

Sarah mentions that professional growers recommend making sure that you get your pots at least an inch off a wood deck, concrete or stone patio to help prevent freezing. Air within the pot gives freezing soil room to expand which reduces the likelihood of a broken container. To accomplish this, just line the bottom of your pot with 2 to 4 inches [5–10 cm] of Styrofoam popcorn or packaging material when you first pot a plant.