Thursday, August 18, 2016

The Giants of Summer by Donna Duffy

Photo courtesy Donna Duffy and Cassie Wilborn
One of the more fun aspects of gardening is growing something that is really big! This time of summer, the garden giants are in their prime, adding exceptional size and wonder to the landscape. Following are four easy “giants” to grow in your gardens.

Photo by Donna Duffy
Aptly named, this is a Mammoth sunflower, almost 13’ tall! I’ve noticed a few of the neighborhood walkers taking a selfie with this sunflower. But you don’t have to grow the giants of this popular annual, there are many varieties of sunflowers ranging in size and color. The sunflower head is not a single flower, but is made up of over 1,000  individual flowers joined at a common receptacle. In Colorado, they will grow in a wide range of soils, including clay, and need at least six hours of full sun a day.  Sunflowers are a New World native that exists throughout the whole of North America down to Central America.  They can be found at archeological sites dating back to 3,000 BC. 

Leonotis leonurus, Photo by Donna Duffy
Native to South Africa, Leonitis leonurus, Lion’s Ear, is a tropical shrub that can grow rapidly to 6’ tall in a single season from seed planted in the garden in early spring. I’ve had them grow as tall as 9’. Tubular two-lipped orange flowers (typical mint family) appear in tiered whorls that encircle the square stems. Flower petals purportedly resemble lion’s ears.  

Photo courtesy
This beauty is a “dinner plate” dahlia. The thousands of dahlias we see today are all hybrids from one ragged wildflower that's native to Mexico. The Dutch hybridizers got their hands on it years ago, and were thrilled at how easily it took to various crosses, changes and "improvements." Today there are cactus-flowered dahlias, water-lily dahlias, peony-flowered dahlias, daisy dahlias — the parade is endless, and with new color combinations every year. Planting dahlias is no different than a daffodil or tulip. Yes, they do need to be dug from the ground in fall (they are not winter hardy in Colorado), but properly stored and cared for, dahlias can last for years. Dahlias range from the miniatures, just a few inches tall, to the huge-flowered Dinnerplates — the wonderful big glossy-leaved plants that grow up to five feet and bloom with flowers 10 or 12 inches across. Check out Plantalk Colorado, Planting Dahlia Tubers, for more information about growing Dahlias. 

Persicaria polymorpha, Giant Fleece Flower, photo by Donna Duffy
Although Giant Fleece Flower looks like a shrub, it grows like a herbaceous perennial, dying back to the ground in winter. However it  makes up for it by quickly growing upwards of 6 ft. tall and almost as wide, the following season. Giant Fleece Flower stays in a well behaved clump and rarely seeds or spreads by rhizomes. It is widely adaptable and requires little maintenance. Persicaria polymorpha is sometimes confused with Polygonum cuspidatum or Japanese Knotweed, which is considered an invasive.

Next summer, try adding a giant to your landscape. It's a great conversation starter!