Perennials in pots. They can last for years. Here are choices

Perennials in pots Like annuals, perennials in pots add color to patios and decks. But unlike annuals, some perennials can live for years in the same pot with minimum care. When they're in bloom, move them to center stage in the garden or patio. In mild-winter areas, now is the time to plant. Wait until spring in colder climates.

Plant for success

Pictured below are five perennials whose growth habits make them well suited to containers. Other promising candidates are gloriosa daisy, purple coneflower, and society garlic.

Choose the pot to fit the variety. Dwarf Shasta daisies such as 'Snow Lady' and the dense gaillardia 'goblin' (both about 12 inches high) are especially good for pots 14 to 16 inches deep; upright kinds like Penstemon gloxinioides (2 to 3 feet tall) look best in deeper containers, 16 to 18 inches.

Nurseries carry perennials in sizes ranging from 4 inches to 5 gallons. A single 2-gallon plant of any of the perennials pictured here should fill an 18-inch-diameter container in a year. It may be tempting to fill the container completely at the outset, but, if you do, the plants will need to be divided or transplanted sooner. As a guideline for an 18-inch-diameter container, plant three 4-inch plants, one or two 1-gallon plants, or just one 2- to 5-gallon plant.

To keep a single perennial from looking lonely in a big pot until it reaches full size, surround it with low-growing annuals (five to seven annuals per 18-inch pot^. The annuals will mature and flower as the slower-growing perennial becomes established. You may get up to six months of color from the annuals before they die and the perennial fills in. Candytuft, Johnny-jump-up, nemesia, and sweet alyssum are suitable annuals to plant now in mild-winter areas. Alyssum may sow itself for repeat bloom.

Perennials featured here are not finicky when it comes to soil--as long as it drains fast, retains some water after draining, and enables air to circulate. USe a potting soil--not a soil conditioner of planting mix intended for amending planting sites in the ground. Thoroughly moisten the soil before transferring it to pots.

Keep the flowers coming

Even perennials that withstand drought in the ground require regular watering in containers. During late fall and winter, pots may need water only once a week. In spring and summer, most require water at least twice a week. Soak soil until water drains through bottom of container.

To compensate for nutrients used by plants and flushed through soil by water, feed regularly with a complete fertilizer. If using a water-soluble type, apply to soil twice a month during the the peak growing season and once a month at other times. As an alternative, work controlled-release fertilizer granules into the top few inches of soil according to package instructions.

Some perennials, like the Shasta daisies pictured above, have a peak bloom season; theirs is late spring or early summer. Others, including the coreopsis and gaillardia, bloom continually over a long period of time. Cut off spent flowers of all types to prolong bloom. On plants that have a peak bloom period, cut all stems down to the lowest green leaves after the main flower season.