How to Winterize Container Perennials

Containerized perennials have become increasingly popular. Decorative pots are available in various shapes and materials and provide the perfect accent to outdoor living areas. Winterizing container perennials in colder climates takes some preparation to ensure that your plants survive.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Mulch or other organic material
• String
• Straw
• Burlap sacking
• Plastic bubble wrap
• Plastic netting
• Horticultural fleece

1. Spread commercial mulch, straw, or leaves over the surface of the container soil. Heavy mulching provides adequate protection for many perennials, such as daylily or hosta.

2. If you have a large enough garden, find an area where you can dig a hole and sink the pots in the ground. Mulch heavily for added protection. The ground insulates the roots from frost damage.

3. Cover the plant with burlap for quick protection. You also can cover the plant with horticultural fleece and tie the fleece loosely around the pot. Another option is to wrap plastic netting around the plant and tie it loosely. Fill the netting with straw or leaves.

4. Use plastic bubble wrap or burlap sacking to surround the container. Tie with string to secure. Add some straw or leaves between the wrap and the pot for added insulation. Be sure to mulch the container soil heavily also.

5. Bring the container indoors. Some perennials can be brought indoors to protect them from winter cold and wind. A garage, basement or shed is a good location. It should be noted that many shrubs, trees and perennials require cold to send them into dormancy so that they will bloom or fruit the next year. Choose the largest container possible for your perennials if they are going to winter outdoors. The larger the pot, the more soil is available to protect the roots.

Tips & Warnings

• Cut back herbaceous perennials planted in containers just as you would if they were in the ground. Ornamental grasses and woody perennials, such as small trees, shrubs and evergreens, should be left intact. Discontinue fertilizing in midsummer but be sure to continue watering until first frost. Deciduous trees, evergreens and shrubs should also have their branches loosely tied with string to prevent breakage in winter winds.
• Most perennials indicated for your hardiness zone will survive the winter in containers. However, many experts suggest that you choose plants that are hardiness rated 2 zones colder than your own for best results.
• The choice of pot material is important when winterizing perennials. Traditional terra-cotta are too porous to be left outdoors and will easily crack. Plastic, fiberglass, wood and the new foam pots are better choices for perennial containers.