Buy plants that fit your climate and soil conditions. Balloon flower (Platycodon grandiflorus) doesn't tolerate heat, humidity or poorly drained soils, so planting in the Deep South or in wet soils is a recipe for failure. Instead, this summer bloomer is a long-lived garden stalwart for USDA Zones 3 to 8, in well-drained soils.
Use cuttings instead of buying more plants. If you love the coleus (such as 'Indian Summer' shown here) that you already have, there's never a need to buy more. Take cuttings in the fall, pot up the new plants, keep them indoors by a window for the winter and you'll have plenty of instant color for the garden after the last frost in spring. For more varieties, exchange cuttings with friends, neighbors or garden-club members.
Take softwood and hardwood stem cuttings to propagate some of your favorite shrubs. The method and timing for woody-shrub cuttings depends on the variety. For the common flowering quince (Chaenomeles) shown here, August is the best time. Softwood cuttings, dipped in rooting hormone, are usually successful.
Choose bulbs that multiply. Unlike most tulips, which tend to weaken every succeeding year, some bulbs just keep going, replicating themselves with no effort from the gardener. Plant a few dozen daffodils, and in five years, you're likely to have many more.
Invest in self-seeding plants. Cleome, like hollyhocks, cosmos, forget-me-nots and shasta daisies, sow themselves but aren't invasive. Snap a picture of each plant so that, come spring, you'll be able to distinguish the leaves of a "keeper" from a weed.
Lasting a Lifetime
Choose long-lived perennials. Plants like scabiosa, wallflower and hardy mums typically last 3-5 years. Other perennials like blanket flower, columbine and coreopsis are equally short-lived but reseed freely. Others are long timers, such as bearded iris, daylily, hellebore, astilbe and bee balm, to name a few. Peonies, seen here, are extremely enduring, sometimes lasting for more than a century.
Divide, Then Multiply
Multiply your plants by dividing them. Some plants like daylilies, bearded iris, yarrow and ornamental grasses need to be divided every few years to reinvigorate them and to reduce overcrowding. What you'll gain for your efforts are new plants to expand your beds and to share with friends.
Watch for Flowers
When a particular perennial is best divided depends in large part on when it flowers. Spring-blooming astilbe (shown here) can be divided in fall or early spring.
Wait until the plant is "resting" to divide it. Bearded iris is best divided about two months after it finishes flowering; many gardeners like to divide their irises in August.
Late-blooming perennials like helianthus, shown here, are best divided in spring. Filling your beds with a variety of perennials that give successive seasons of bloom, blooming shrubs and colorful conifers means you'll be less apt to load up on trays of annuals to fill holes in the landscape.