Containers, zone 7, and here comes winter

October 23, 2014

A nor’easter just blew through, but the sugar maples out my window still light up this grey day with yellow, red, and orange foliage. Winter is coming.

The containers in question sit, empty, elevated, on beautiful Avondale stone  terrace, placed to provide privacy and interest as this new garden begins to grow. Now what?

According to various nurserymen, plants will grow in these pots easily and happily, or not at all. Wait. What? This is not helpful information.

As usual, the truth lies somewhere in the middle. Chose the right plant, give it time to adapt, take care to water it through the winter, and that plant will live. Here are The Cold, Facts on Protecting Potted Plants This article ends with a happy caveat for all of us in zone 7, the more extreme protective measures for potted plants are not necessary here.

Chose the right plants~
Perhaps the most important characteristic of any plant you might be considering for the containers is its hardiness. Choosing plants that are hardy to zone 5 means that these plants will tolerate the stress of the temperature extremes above ground here in zone 7.

We are further looking for privacy and interest from the plant choice. Mountain laurel, kalmia latifolia , species ‘Snowdrift’, ‘Olympic Fire’, or ‘Peppermint’ will grow to 10 feet at maturity and provide a lush screen for privacy and seems a good potential choice. It’s growth habit is dense and mounding, and can be pruned happily.

Here’s an array of  dwarf conifers to consider. Behold Conifer Kingdom and Brent Markus . A closer look at Brent and his operation is here, in Form and Function  The dwarf conifers provide somewhat less privacy as they will not form a screen per se, but all is forgiven, as many are endlessly interesting.

Cornus sericea ‘Cardinal’ red twig dogwood, or its ilk, might be a good choice for the pots to be put in front of those glorious mud room windows. After a year or so, if that view gets old, they could be planted out in the landscape to brighten up the evergreen privacy screening.

Give the plants time to adapt~
Winter looms. It’s such a great time to ponder exactly what plants you want where, which is surely one of the great joys of gardening. Maybe the best choice, for at least some of the containers, is to put the soil in them, and then create an evergreen arrangement, something like these but in scale with the containers.

Give the plants water in the winter, plus a little extra insulation~
A plant hardy to zone 5 will do well in a container here, provided that it is watered throughout the winter, even when the world around it is freezing.
Water, and some modicum of warmth for the roots, will help the plants succeed.  While not strictly necessary for zone 7, lining the interior of the pots with packing peanuts before filling with potting soil seems like a good precaution. By planting in a container, we are exposing the root system, which does not go dormant, to the extremes of temperature variation above ground. The peanuts will moderate those extremes some.

☆ Importantly, get plant trolleys and put them under the empty containers. Once the soil and the plants are in, those pots will be heavy. You will thank yourself later. Further, some pine straw can spend the winter between the cold stone of the terrace and the bottom of the pot.☆

Gardening is all about surprise and the unexpected, and not at all about guarantees, but the plants in these containers will have an excellent chance at survival, I think.