Hardy and handsome plants for cold-weather containers

Nurseries are stocked with an abundance of vivid fall and winter beauties that can be planted in containers now for months of enjoyment.
At the nurseries, check for special areas that highlight fall- and winter-hardy plants for containers. Amid the colorful, blooming offerings, look for plants with texture, such as grasses, euphorbias and heucheras, and small shrubs like nandina and conifers. For a Halloween-inspired container, try a striking combination of dark foliage plants set off by bright flowers. The leafy Heuchera 'Obsidian' could be combined with ajuga 'Black Scallop,' black mondo grass and orange mums for a zippy elegant seasonal planting. You could also plant sturdy winter pansies in orange, yellow and even black.
Winter wonder plants
After the trick-or-treaters depart, you might want to retain the larger, dark plants and add white artemsia and burgundy pansies for a fresh color combination. Another intriguing winter beauty, grown by Skagit Gardens, a Mount Vernon wholesaler that supplies Northwest nurseries, is Euphorbia 'Glacier Blue' with icy blue foliage and cream at the leaf margins. Debbie Hewlett, New Products Introduction Team Leader for Skagit Gardens, says 'Glacier Blue' combines well with pinkish heucheras and rosy pansies.
Container ideas
Here are some tips for keeping your containers looking good through winter:
Soil: Any good potting soil will work. However, drainage is particularly important for plants that will be under the assault of rainstorms.
To improve drainage in containers that once held summer annuals, dump out the soil and add in enough perlite for a mixture of one-fourth perlite to three-fourths soil. (Pumice can be used instead of perlite.)
If your summer containers had a soil mix with polymers or other additives to hold water, set it aside for use next year. Winter container plants won't need the extra dampness.
When filling containers, do not add gravel or bits of broken pots to the bottom. Gravel and pot shards will hamper drainage. Instead, fill the entire pot with the soil mixture.
A paper coffee filter over the drainage hole will keep the soil from slipping out but still allow water to disperse.
Plant now: Getting roots into soil in October will help them establish before really cold weather arrives.
Use a big container: Choose a container at least 12-18 inches tall and 18 inches across. Not only can you tuck more plants into it, but the room will also help protect roots from the cold. Leave a 2-inch margin between plant roots and the pot wall for more protection.
Don't use saucers under containers. Plantings that are left standing in water-filled saucers can rot. Instead, set containers on planter feet or bricks.
Plan on hardiness: Plants listed here are hardy into the low 30s. If temperatures drop into the 20s, shelter the plants in a garage or other area protected from freezing.
Garden expert Mary Robson, retired area horticulture agent for Washington State University/King County Cooperative Extension, appears regularly in digs and in Practical Gardener in Northwest Life on Wednesdays. Her e-mail is marysophia@olympus.net.