GET YOUR GARDEN READY FOR ZINNIAS
Zinnias shine all summer long in the Colorado cutting garden — and containers
The showstopping color of this flower is an annual must-have in a Colorado cutting garden. So dust off your gloves and grab your spade — the growing season is upon us.
In the cutting-garden alphabet, the best comes at the end. Sure, alyssum have sweet blooms, lilies are lovely and there are many other flower options along the way, but zinnias are the showstoppers.
Whether cheerfully clustered along a sunny border in a variety such as Profusion Red, a 2017 AllAmerica Selections Winner, or commanding center stage at their full height of 3 feet with dahlia-like flowers in a Burpee’s Giant Flower Mix, zinnias are annual must-haves in a Colorado cutting garden.
What’s equally appealing about this annual is that it is easy to grow, produces flowers all summer long and attracts such pollinators as bees and butterflies.
“They are under-appreciated considering they make such a big statement in the garden,” says Renee Shepherd of Renee’s Garden, a California-based seed company that offers dozens of zinnia mixes blended from its seed suppliers in America, Holland and Germany. “There’s no need to start them early, because you can easily sow them as soon as nights are in the 50s and days are warm.”
Space seeds about 2 to 3 inches apart in rows 12 inches apart, cover about K inch deep and gently firm the soil, Shepherd says. “They’ll emerge in seven to 10 days and you thin them when they’re large enough to handle.”
While not picky about soil, zinnias do best in full-sun locations when the soil drains well and gets consistent moisture and fertilization.
“Zinnias don’t benefit from getting started too early,” agrees April Shelhon, marketing horticulturist for Broomfield-based Botanical Interests seed company. She typically plants her zinnia seeds a week or two after the average last frost date. (Gardeners along the Front Range use Mother’s Day as a rule of general rule of thumb for planting). Once the zinnia plants have four to five sets of leaves, she’ll pinch back the top of the plant to encourage branching.
Water plants from the bottom rather than the top if possible and use mulch to prevent the spread of mildew, the primary fungus that affects zinnias. Keeping plants wellspaced also provides good air circulation. Shelhon advises using a balanced fertilizer and following the manufacturer’s recommendation on how often to apply it.
For her wedding in 2015, Shelhon grew the flowers for her bouquet and included green Envy zinnias in the mix, accented with lacy orlaya and nigella seed pods. On that occasion, she started seeds indoors. “I was afraid if I waited too long to plant them, they might not be ready in time for the wedding.”
Shelhon is fond of multicolor zinnia mixes since they bring drama to the garden. “You can see the bouquet without having to buy 10 different packs of seeds,” she said.
When the time comes to pick flowers, many gardeners make the mistake of waiting too long. “Cut them when the center yellow flowers are tiny,” and the outer petals haven’t fully opened, Shelhon says. Morning is the best time to harvest.
Zinnias are prized by flower fans today, but that wasn’t always the case.
Spanish explorers who came upon zinnias in Mexico referred to them as “maldeojos,” or causing sickness of the eye, Shelhon says.
They were designated as a genus of flowers in the asteraceae family by botanist Carl Linnaeus and he named them for 18th century German botanist and anatomist Johann Gottfried Zinn.
Zinnias didn’t become a success with home gardeners in America until the 1950s, when years of breeding began to produce flowers with more saturated colors and larger sizes, she said.
Narrowing down what varieties to grow might be the hardest decision gardeners have to make when it comes to zinnias. Burpee has 40 different varieties available on its website this year, 11 of which are exclusive, says Robin Ruether, the company’s product manager for ornamentals.
Another great thing about zinnias is that if you keep them cut back and deadheaded, they’ll continue to produce flowers all summer long. The company’s Cut & Come Again Mix plays up that feature, but it’s true of zinnias in general.
Zinnias look great in the garden when planted among other summerblooming annuals, or place them in small groups among perennials, Ruether says.
Use shorter zinnia varieties for container plantings. Avoid overcrowding or the flowers may be sig- nificantly smaller than they should be and the plants may be taller. For containers, use a commercial potting mix rather than ordinary garden soil and make sure the vessel has adequate drainage. Container grown plants will require extra water and fertilizer. Keep any eye out for signs of wilt or a nutrient deficiency.
Is there anything not to love about zinnias?
“It’s true they have no scent,” Shepherd says, “but they attract butterflies and they make beautiful bouquets.”