By Glenn DiNella
I’ve heard more than one person ask: “Why would anyone invest money in annuals? They die after one season, and you have to replace them.”
They are correct, of course. Annuals are plants you have to replace - typically every six months in the Southeast. We tend to plant one crop in the fall. Pansies, violas, snapdragons, ornamental cabbage, and kale are popular choices for providing color throughout winter.
The answer to their question is you just cannot get as much “oomph” from perennials. Blooming annuals give their all until they are spent at the end of the season. You are lucky if you get a month of flowering from most perennials.
Keep in mind that annuals planted in containers are more exposed to the elements. In winter their roots get colder than the same plants nestled in a garden bed. This past winter, when temperatures dropped into single digits, I noticed some annuals in small containers didn’t survive. You can bring small pots indoors or insulate larger ones in bubble wrap, blankets, sheets, or tarps to help them survive particularly cold nights.
By the same token, annuals in containers can get hotter and dry out quicker during summer months. Look for a moisture-control potting soil when you fill your containers. Or add water-absorbing crystals to a regular soil mix. These tiny particles swell up to retain moisture the plants can use later as soil dries. Drip irrigation kits are also an option.
Here are a few of my favorite annuals for providing color throughout the long, hot summer months. Deadhead your annuals (cut the spent flowers off), and fertilize occasionally to keep plants blooming and looking their best.
Geranium. There is just something classy about geraniums. Trailing geraniums are good for cascading over the side of a pot, but the standard type also can perform this duty. I plant them at an angle near the edge of the container and let them droop over the side. These hot-pink geraniums are a favorite of my wife; I prefer red geraniums.
Portulaca. Also known as moss rose, this low-growing succulent is the camel of the annual world. Its fleshy leaves and stems store up water, so the plant can survive -- even thrive -- in all-day sun in a container. Portulaca also sports a rainbow of colorful blooms about the size of a quarter: red, pink, coral, yellow, and orange.
Mandevilla. Against a brick wall that gets full sun all afternoon, a bright-pink mandevilla twines its way up a small trellis placed in the pot. Although mandevilla technically is a tropical vine, most Southern gardeners treat it as an annual and replace it in fall. With regular watering, it can take all the heat you can throw at it. The same goes for the complementary pink-flowering vinca planted at the feet of the mandevilla.
Hibiscus. Another hot tropical great for summer containers is hibiscus. Pick your favorite bloom color -- red, pink, yellow, or orange -- and pair it with another sun-loving annual such as these marigolds. Another great thing about marigolds is they are somewhat cold hardy, so they keep blooming well into fall. You can try to grow the hibiscus indoors for winter, or simply toss it on the compost pile.
Zinnias. Much like the classic geranium in a pot, a pot of bright zinnias bursting with color lends a simple understated elegance. These friendly flowers love full sun, and bloom their heads off all summer. They can feature blooms in white, yellow, orange, pink, coral, yellow, red, and rust; some have multicolor petals on the same flower. Butterflies LOVE zinnias. In fall it’s fun to collect the seed heads and store them away. Try sowing the seeds in spring and starting a new generation of these vibrant, easy-to-grow annuals. Learn more about annuals here.