While resting on the porch over Labor Day, I realized the dogwood trees were turning red and dropping some leaves. I spent the day cleaning up my growing area; Now, I can anticipate the cold weather coming. How strong is Gerber chamomile? This may seem like an unusual question as the heat of summer continues, but early fall is the perfect time to pot or divide perennials.
I’m thinking of planting several healthy Gerbera daisies that have thrived in containers. Can these daisies withstand the cold of winter? It’s easy to give up on annuals. Zinnia and marigold seeds can be sown in the spring.
Tender perennials are difficult to part with. In terms of cold hardiness, it is difficult to determine the exact line of survival for tender perennials.
Gerber daisies (Gerbera jamesonii) are bright, colorful flowers commonly grown in gardens as bedding plants or in containers in South Carolina. Native to South Africa, they are members of the Asteraceae family and are also related to sunflowers and marigolds.
The genus name, Gerbera, honors the 18th-century German naturalist Traugut Gerbera. “Gerbera daisies, commonly grown as annuals, are tender perennials in warmer parts of South Carolina,” warns the Clemson Home and Garden Information Center. Gardeners in USDA Plant Hardiness Zone 8 may have success growing gerbera daisies as plants. Perennial if the garden is covered and plants are protected from freezing temperatures in winter.A cool but frost-free location, such as a cold frame or unheated garage, if it has some light and is not flooded.
According to the USDA, Aiken is in Zone 8-A for plant hardiness. The USDA Plant Hardiness Zone Map is the standard by which gardeners and growers can determine which plants are most likely to thrive in a location.
You may doubt the hardiness of a particular plant if you want to keep the plant beyond the growing season. For example, blue porterhouse is a popular pollinator in South Florida, where bright blue flowers appear halfway up funky, swirling, upright stems. Even in South Florida, this plant is described as “only moderately cold hardy.” They definitely need winter protection to survive until spring.
What about sages and salvia? Many sages (Salvia species and hybrids) are native to Mexico and Central America. Because they are heat and drought tolerant, they are ideal for summer yards. In the spring new growth can appear again, but again, probably not. With luck, salvia plants grow fuller and more beautiful with each passing year. The top growth may die from frost, but underground, the crown and roots will survive. Soil drainage is key to survival, and some varieties such as the sage rose can survive the cold in sandy soil.
What about plumbago? Here the answer depends on which type. “Confusingly, there are two different types of bluebago plants commonly sold at nurseries,” explains Walter Reeves, a gardener in Georgia. The first, Plumbago auriculata, is a slender, semi-vigorous perennial. It usually dies in the winter here. The other, Ceratostigma plumbaginoides, is a hardy ground cover that only blooms in the fall. Light mulching with pine straw is recommended.
What about the princess flower, also known as the glory bush? What about blooming abutilons? These plants are tender perennials that come from the tropics, South America, Texas and Florida. They are unable to tolerate temperatures below 25 degrees and need winter protection. In pots, they can be moved to the cool, frost-free location mentioned above along with ferns, begonias, hibiscus and other tropical plants that enjoy heat-filled summers but may be damaged by severe cold spells.
Many annuals—which are replanted every summer—are heat-tolerant. The most heat-tolerant annuals may actually be wildflowers. Blanketflowers, copsis and rudbeckia are ideal candidates that are known to adapt to infrequent watering and poor soil conditions, and that grow well and replant in hot weather. You don’t have to worry about their cold hardiness because the seeds will survive and grow again. Annuals also tend to have a longer flowering period than perennials, so that’s a plus in their column as well.
Plant performance depends on the overall climate. The length of the growing season, timing and amount of rainfall, winter lows, summer highs, wind and humidity all play a role. Through care and research into plant hardiness and heat tolerance, we as gardeners can successfully find the right place for any new plants we encounter and choose the right plants for the spaces we have.
Millbrook Baptist’s AMGA Lunchbox Series will feature Adam Gore at noon on September 15. Gore is an Ag/Hort Extension agent for Abbeville County and will talk about preparing turfgrass lawns for cold weather. Looking forward to October, be sure to mark your calendar for October 20 when Make It Grow host Amanda McNulty will be entertaining while answering our gardening questions.