|URBANA, Ill. — Planting annual flowers too early in the spring may result in another trip to the garden center to replace the original purchases, said a University of Illinois Extension horticulture educator.
“These tender plants can be injured or killed by sudden low temperatures or frost,” said Susan Grupp.
To gardeners, the term “annuals” means flowers.
“They are typically planted in spring and produce flowers all through the growing season and then die with the first frosts in fall,” she said. “Annuals are top performers - they bloom their hearts out for us and make a great addition to the yard and garden.”
Some perennials and biennials grow quickly from seed and begin to flower immediately but do not survive our cold winter weather.
These plants are treated as annuals and include impatiens, vinca, geranium, coleus, and snapdragon.
Annuals may be classified as hardy, half-hardy, or tender. These terms are important - they help you determine the proper time for transplanting to the garden.
Hardy annuals withstand the most cold and can tolerate light frosts without being killed or badly damaged. Half-hardy annuals can tolerate cold, wet, damp weather but may be damaged or killed by frost.
“Tender annuals need warm soils to germinate and grow properly and also warm air temperatures to produce the best flower display,” said Grupp.
“So, if you can’t resist the flowers in the garden center, be sure to choose the hardy ones for early plantings and wait to plant tender, warm-lovers until the risk for frost has passed.”
Hardy annuals include: flowering kale, pansy, snapdragon, sweet alyssum, strawflower, calendula, cornflower, dusty miller.
Half-hardy annuals include: ageratum, geranium, dianthus, gazania, lobelia, marigold, nicotiana, petunia, and salvia.
Tender annuals include: tuberous begonia, coleus, celosia, portulaca, verbena, zinnia, impatiens, browallia, gladiolus, sunflower, vinca, and cosmos.
For more gardening information from University of Illinois Extension, visit www.urbanext.uiuc.edu/hort/index.html
This farm news was published in the March 15, 2006 issue of Farm World.