Last Updated on November 24, 2018 by Kimberly Crawford
You can lug large container plants into the greenhouse or garage for the winter, or you can provide each plant with frost protection right where it lives.
All serious gardeners have special plants; they spend large amounts of time and money on these beauties and will do almost anything to protect them from damage. When gardeners like this live in the North, where the temperature drops every Fall and arch enemies frost, freeze, snow, and ice are not far behind.
The traditional means of keeping these plants safe from their enemies involves hauling both container and plant into some sheltered location, such as a greenhouse or garage. If the precious plant is in the ground, the gardener hauls out the stakes, burlap, and twine to build a winter coat for the dear and hopes the weather does not play the nasty trick of sending unseasonably warm weather once the winter coat is secured.
Put a Winter Coat on Large Container or Specimen Plants
Perennials, shrubs, small trees, or vines grown in large containers can be hard to move because of their weight or size. Trellised container plants present a particularly moving challenge. Rather than trying to move these plants into a protected place, bring the frost protection directly to the plant.
The Planket(tm) is one example of a new style of frost protection products that lets you avoid the Fall moving scenario each year. Planket is a green, spunbond, polyester cover with a draw string used to tighten the circular cover around the base of a plant or the top of a container. The smallest Planket is 6 ft. in diameter.
The largest Planket is 10 ft. by 20 ft and can be used for one or more raised beds, a stone or brick wall with plants on top, or other large scale uses. The Planket is sold through Home Depot and Smith and Hawken. Similar container covers are available from a variety of other retailers.
You can also make a container cover using any nonwoven polyester row cover fabric. Either sew two lengths of common 4 to 6 ft width row cover together or purchase a roll of extra-wide row cover. Lay the joined or wide fabric on the floor and cut a circle that is at least twice the diameter of the container you want to cover. If the plant in the container spreads beyond the container, increase the diameter of the circle accordingly.
Using iron-on fusing tape or your sewing machine, make a 2-inch hem around the outside of the circle. Leave at least a two-inch opening in this hem in order to insert the drawstring.
Using a knitting needle, bamboo skewer or chop stick as a shuttle, tie or tape the twine or rope to the shuttle. Insert the shuttle into the opening created by the hem and push the drawstring through by pulling the fabric over the shuttle onto the twine until the shuttle comes out through the opening where it went in.
Tie a knot on each end of the drawstring big enough to prevent it from easily being pulled into the hem. Take the circular cover to the container and place it over the entire plant and down over the top of the container. Pull both ends of the drawstring to bring the cover tight around the container and tie or clip securely. You do not want cold air seeping in under the cover.
Cover Smaller, In-Ground Plants
Around since Victorian times, the cloche is historically a single glass bell with a hole in the top for ventilation. It is placed over an individual plant to protect from frost or freezing. Today, you can find Victorian-style cloches made of plastic.
A modern version of the cloche is the Wall ‘O Water(rm) or Kozy Kote(tm). This plastic cylinder is quilted to create multiple 1 to 2 inch wide pockets into which you put water after placing the whole cylinder over a plant.
The water is warmed by the sun during the day and at night radiates the heat to keep the air warm around the plant. the Kozy Kote uses red plastic, since red is believed to provide tomatoes with the specific part of the light spectrum they prefer.
Of course, large plastic bottles or milk jugs with their bottoms cut off are also good at protecting single plants from frost. They also keep rabbits, chipmunks and other small creatures at bay. Be sure to either bury the container in a couple of inches of dirt to secure it in place, or place a stake near the plant and set the container over the stake
Recycle Materials to Create Protective Covers
The criteria for a protective cover for any plant is that it serves to insulate the plant from drops in temperature, while still letting the plant breathe. Almost any woven fabric fits this criteria.
Most woven fabrics can be used to create either a circular cover as described above, or to wrap a plant as you would a gauze bandage around a leg wound. When wrapping plants, leave some air space to collect the warmth the plant produces. Use jute or hemp twine to hold the wrapping in place.
Burlap has been a staple of the Northern garden for decades because it is inexpensive and durable. Most of us do not buy flour or feed in burlap bags anymore and, thus, accumulate a pile to use for winter frost protection. We do, however, save the occasional bed sheet, cotton blanket, or other woven fabric.
Bubble wrap – the clear plastic material used to protect delicate objects during shipping – is also a good form of insulation. With bubble wrap, you do not want to wrap the material directly around the plant; put 3 or 4 stakes an inch or two from the plant and wrap the bubble wrap around the stakes.
Shipping tape or clear duct tape can be used to secure bubble wrap. For the top of a bubble wrap cover, use bullnose clips, clothespins or twine to close any opening; you want to be able to open the cover on any unseasonably warm days.
