The famous garden designer Gertrude Jekyll grew containers of flowers to fill in dull spots in perennial borders. As a longtime perennial gardener, I can testify that few are blooming by the end of July. I use containers of annuals to provide visual interest during the dog days of August.
I prefer annuals that do not need much deadheading. Impatiens and vinca are self-cleaning profuse bloomers that come in a terrific array of colors. Sun-tolerant coleus have fabulous foliage that looks great all season. I often use them as the centerpiece of the “thriller-filler-spiller” container formula in which one circles a dramatic centerpiece with low growing plants and some to cascade over the edge of the pot. Being a bit lazy about maintenance, I opt for foliage spiller plants such as Creeping Jenny.
Photo: Container composed by my husband, Paul.
By the way, “Jenny” is thought to be a corruption of “chinny” which was the common name for diphtheria back in the day. Why a pretty groundcover is named after a disease is beyond me.
This is not my patio. It is a street corner in the Hague.
Hanging baskets are an ever-popular option for seasonal beauty. Whether you buy a pre-planted basket or make your own, prepare to care for them daily. Because they have a relatively small volume of soil and are hanging in the hot wind, they dry out
quickly and may very well need to be watered daily. During the hottest days of summer, they may need water twice a day. Over time, water creates fissures through the soil so the water is not wetting the whole soil ball. When this happens, you must take the basket down and soak it in a bucket for about an hour. With all that watering, you are going to need to fertilize frequently with a liquid product as well as keep up with deadheading.
You can grow perennials in containers. It is a great option for plants that tend to crowd their neighbors as well as those needing special growing conditions. Agastache is deer resistant and attracts pollinators, hummingbirds and butterflies. The flowers come in a wide range of colors from cool blue to warm coral. It cannot tolerate wet feet or clay soil. Being cold tolerant, it is the perfect candidate to grow in containers. I would use a cactus potting mix or incorporate my favorite amendment, expanded clay, into ordinary potting soil to improve drainage.
If you have a place to bring in tender perennials for the winter, you can grow your own Meyer lemons or a bay tree.
After attending a program about growing roses in containers, I decided to try doing it. I started with two roses and added three more the next year. I use fairly large containers to accommodate the mature root system. Choose one that is at least 18 inches in diameter. Because this is its “forever” home, drainage is critical. Drill extra holes if needed. I have my pots elevated on wheeled plant caddies. Add expanded clay or perlite to the potting soil to maintain pore space as well as a slow-release fertilizer. Supplemental liquid feedings are also needed to keep the roses robust.
Who does not find windowboxes charming? I tried them once. They require the same daily care as hanging baskets. At the time I had a full-time job outside the home. What was I thinking?
Plan ahead to prevent plant abuse!
As spring approaches, master gardener Ann Bartlett prepared this series of container gardening articles for gardeners who cannot contain themselves until the soil warms.