By Dan Gill

LSU AgCenter Horticulturist

(02/17/17) Every year, Louisiana gardeners see amazingly beautiful beds of pansies, violas, dianthus, snapdragons and many others whose peak blooming season is in late March through May. Wanting to create the same beauty in their gardens, they go out to nurseries in April, purchase these plants and plant them in their gardens. Invariably, they are disappointed when their plants never achieve the spectacular results they saw in other people’s gardens.

There is a good reason for this. The most spectacular mid-to-late-spring displays of cool-season bedding plants were planted last fall or at least by late winter or early spring. Early planting allows the bedding plants to develop into larger plants with robust root systems by the time the crescendo of the blooming season arrives in April. Cool-season bedding plants planted in April cannot, and never will, achieve the beauty of those planted earlier.

The problem is that April is very close to the end of the cool season. By May, daytime highs generally begin approaching the 90s, signaling the beginning of summer and the gradual decline of cool-season bedding plants. So late-planted cool-season bedding plants simply don’t have the time to develop into the large, robust plants achieved by planting in the fall. Instead of several months to grow and develop in the chilly weather they prefer, cool-season bedding plants planted in early April have a scant couple of months or less before they begin to fade.

Economically, you get far less “bang for the buck” when you plant cool-season bedding plants late in the cool season. A six pack of pansies cost the same in November as it does in April. A November planting, however, provides flowers for about five or six months, while an April planting provides flowers for six to eight weeks.

The key, then, to outstandingly beautiful beds of spring-flowering bedding plants is early planting – and it is not too late. Cool-season bedding plants planted in February still have time to make nice robust plants that will provide an outstanding display in late March, April and early May.

Area nurseries are well stocked with transplants of cool-season bedding plants now, and you should be able to select the type and colors you desire for your garden. At this point, it’s too late to plant seeds, so you should use transplants.

Select cool-season bedding plants in colors that are harmonious. Colors should be grouped together in masses, and try not to use too many different colors in the same bed. The visual display in an area where a few colors have been used en masse is generally more effective than a sprinkling of many colors, especially if the bed is to be viewed from a distance.

Cool-season flowers come in a variety of shapes and sizes, from the ground-hugging alyssum and lobelia to the towering hollyhocks and delphiniums. Besides color, plant heights should also be considered when selecting and placing bedding plants into the landscape.

Many cool-season flowers can be planted into the garden now. Check your local nurseries and garden centers for transplants of alyssum, annual baby’s breath, annual candytuft, annual phlox, bachelor’s button, calendula, delphinium, dianthus, diascia, dusty miller, English daisy, forget-me-not, foxglove, geranium, hollyhock, larkspur, nemisia, nemophila, nicotiana, ornamental cabbage and kale, pansy, petunia, poppies, snapdragon, statice, stock, sweet pea, toadflax and viola. All of these are hardy down to about 20 degrees; most are hardy down to the teens.

A few of the cool-season bedding plants are somewhat more heat tolerant. These would be better choices should you still decide to plant cool-season bedding plants late in the season around April. These include alyssum, annual candytuft, annual phlox, Dahlberg daisy, dianthus, dusty miller, nicotiana, petunia, snapdragon and statice.

My general advice, however, is that by late April the danger of hard freezes is past in our state, and we can begin to plant warm-season bedding plants. Economically, it makes more sense to plant warm-season bedding plants in April and May as they can be reliably expected to bloom from a spring planting until at least late summer, rather than giving up in the heat of late May or early June the way cool-season bedding plants will.

So, if you currently have some empty areas in your flower beds or want to create and plant some new beds, now is the time to plant cool-season bedding plants into those areas for best results. Planted now, you can still expect an outstanding display in late spring.

People will undoubtedly still be planting cool-season bedding plants in April, and you may as well, if you like. The nurseries will certainly still have them available because of the demand. But now you are more aware of the pros and cons of planting cool-season bedding plants that late, and you can make a more informed decision.

Sorbet viola. Photo by Dan Gill/LSU AgCenter

Redbor kale. Photo by Dan Gill/LSU AgCenter

Camelot foxglove lavender. Photo by Dan Gill/LSU AgCenter

Amazon Rose Magic dianthus. Photo by Dan Gill/LSU AgCenter