Labor Day and cool fall weather may spell the end of the line for flashy summer annuals, but that doesn’t mean it’s time to pack up the flowerpots. Ready availability of crack-resistant, winter-durable pots make it easy to replant the pots for a new fall or even winter display.
Concrete, metal, wood, plastic and the many new choices of foam pots are all good options for fresh cold-season combinations. Ceramic and terra cotta are much more expensive and likely to crack in winter, especially when soil freezes and expands.
Plants to try
An obvious change is to simply substitute cold hardy and/or fall-blooming plants for the marigolds, zinnias, sweet potato vines, and other summer heat-lovers. Good candidates for fall decoration include mums, the best-known fall flowers that can sometimes be planted in the ground after blooming to return the following year. Ornamental cabbage and kale with their wonderful colorful and healthy foliage are also widely available at garden centers in fall. These thrive in pots, where they can look fresh for months. Avoid planting them alone in rows as they are stiff and formal, lacking much grace. Add short grasses to soften the look. Cold-hardy annuals including pansies, violas, snapdragons (Antirrhinum), dusty miller, dianthus, and sweet alyssum (Lobularia maritima) are other good choices. These are the same plants gardeners rely on to get a jumpstart in still-frosty early spring. And don’t overlook the perennial and herb sections of the garden center for hardy plants with colorful herbage. Lungworts (Pulmonaria), coral bells (Heuchera), and foamy bells (Heucherella) offer three of the best and most varied leaf colors. They remain good-looking through much of fall and even winter. Hostas are fine until hard frost. Golden oregano (Origanum vulgare ‘Aureum’), purple sage (Salvia officinalis ‘Purpureum’), and silver thyme (Thumus vulgaris ‘Hi-Ho Silver’ or ‘Argenteus’) are three colorful herbs that make good options too.
Another possibility is converting some of your larger pots into evergreen containers. Both needled and broad-leaf evergreens do just fine in pots, as long as they’re kept moist with weekly drinks when the soil is dry and thawed. Upright evergreens such as young arborvitae (Thuja), dwarf spruce (Picea), pyramidal hollies (Ilex), and pyramidal yews (Taxus) make ideal potted sentinels on either side of a door. They also give the option of adding lights and decorations to become mini potted outdoor holiday trees in December.
Other evergreen specimens such as variegated boxwoods (Buxus sempervirens ‘Argenteo-variegata’ or ‘Aurea-variegata’), golden falsecypress (Chamaecyparis pisifera ‘Plumosa Aurea’ or ‘Filifera aurea’), golden yucca (Yucca filamentosa ‘Golden Sword' or ‘Bright Edge’), and dwarf Hinoki cypresses (Chamaecyparis obtusa) dress up otherwise barren cold-season landscapes, especially when combined with some of the hardy plants mentioned above. When these live evergreens outgrow their pots, repot them into larger containers or plant them in the ground in spring.
Cuts for containers
A third option — and easiest of all — is replacing flowers with cut evergreens harvested from the yard. Grab your pruners and start by cutting branches of Douglas fir (Pseudotsuga menziesii), white pine (Pinus strobus), Japanese cedar (Cryptomeria japonica), blue spruce (Picea pungens), and whatever else you might have growing.
Cut the bottom of the stems on an angle so that they can be inserted into the soil more easily. Stick these branches directly into the soil to make a pleasing evergreen arrangement. They’ll keep their needles and their color for months, much as a cut evergreen stays green indoors for weeks during the holidays.
Then look for branches with colorful berries. Some of the best are winterberry hollies (Ilex verticillata), junipers (Juniperus), evergreen hollies (Ilex), Heavenly bamboo (Nandina domestica), firethorn (Pyracantha), viburnums, and beautyberries (Callicarpa). Also look for branches with interesting color and shapes. Good subjects include red-twig dogwood (Cornus sericea), coralbark maple (Acer palmatum ‘Sango-kaku’), bamboo, and the twisted branches of Harry Lauder’s walking stick. Insert these cut branches with the evergreens to create an attractive effect.
Finish off the pot with any other colorful plant accessories you can scavenge: plumes of ornamental grasses, rose hips, pine cones, dried hydrangea heads, and the limey, baseball-sized fruits of Osage orange (Maclura pomifera) for example. Besides looking beautiful for weeks and even months, these cuts need no water or fertilizer. You can refresh the pots with new cuttings throughout winter. By then, the days will be warming, and it’ll soon be time for new petunias, zinnias and geraniums.