These simple maintenance tasks keep your patio planters and window boxes looking their best throughout the growing season and help cold-climate gardeners prepare for winter.
Water frequently. Closely spaced plants packed into a small volume of soil need watering as often as once or twice a day, especially in hot, sunny, dry weather. When you water, be sure to saturate all the soil in the pot-not just around the edges. Pots that dry out too quickly may have more plants in them than the soil can support. Remove some plants, prune them back, or move the pot to a less sunny location.
Fertilize regularly. Rapidly growing plants need plenty of nutrients. Frequent watering and the limited amount of soil in container gardens makes the need for fertilizer critical. Mix slow-release fertilizer pellets into the potting soil, according to package instructions. Add additional nutrients throughout the growing season by dissolving a water-soluble fertilizer in the watering can once every week or two. Use a one-half to one-quarter strength dilution, or follow package instructions.
Groom and remove dead flowers. Keep plants looking lush and full by pruning leggy stems back to buds or branches and removing off-colored and damaged foliage. Many plants continue to produce new flowers if you remove the spent blooms before they set seeds. Pinch the flower stems back to just above a leaf or bud.
Change plants seasonally. When the plants begin to look tired and past their prime, pull them out and replace them with fresh plants. You can keep your container current with seasonal themes by growing a succession of plants, such as bulbs and primroses in the spring, annuals and vegetables in the summer, and colorful kale and pansies in autumn.
Prepare for winter. In cold-winter climates, containers and their contents need protection from freezing temperatures. Even hardy perennials, trees, and shrubs cannot tolerate completely frozen roots. Terra cotta and ceramic pots may crack if left outside to freeze. Empty their contents into the compost pile and store the dry pots in a protected garage or cellar. Wrap chicken wire around the pots of small trees and shrubs and stuff with loose mulch, such as straw. Store in an unheated but not freezing garage or basement for the winter.
Reduce watering chores by choosing light-colored, non-porous containers such as plastic or glazed pottery. Protect pots from full sun and wind.
Rotate containers to encourage plants on all sides to grow evenly. Plants on the shady side tend to get leggy as they stretch for the sun.
Photography by Suzanne DeJohn/National Gardening Association