The Southeast United States is showing off right now with the native Stokes' aster, a wildflower that almost anyone can grow. If you crave the color blue, then it's a must for you.
Botanically speaking it is known as Stokesia laevis and is cold hardy through zone 5. (Salt Lake/Provo area is zone 5.) It is indeed in the aster family but is a far cry from your fall blooming selections.
The flowers are huge by aster standards, reaching 3 to 4 inches across and are borne on stems reaching around 12 to 18 inches in length. Some have described them as similar to a cornflower, and while I could see similarities, the flowers deserve much more in the way of accolades.
To me the flowers can just about compete with the exotic appearance of the passionflower. Although they are smaller in size their intricate design is most welcome in the perennial border.
The large flowers that adorn this plant keep producing for several weeks in late spring to early summer. Choose a site in full sun for best blooming, however partial shade is tolerated much better than many other perennials.
Make your beds well drained by incorporating 3 to 4 inches of organic matter like fine pine bark, humus or compost. They do prefer a pH that is slightly acidic, and well-drained soil is pretty much mandatory if you want it be a long-lived perennial. Wet winter feet can spell doom.
Till your bed to a depth of 8 to 10 inches and add 2 pounds of a slow-release, 12-6-6 fertilizer into the bed. Plant 6-inch to gallon-sized plants now and set out at the same depth they were growing in the container. The plants reach 18 inches in height. You will want to space them 15 to 18 inches apart.
With temperatures already starting to approach hot, be sure and apply a good layer of mulch and train the roots by watering deeply. They sometimes rest in summer to bloom again in the fall. They form large clumps that are easy to divide in early spring. Go into the winter tidy and with a protective layer of mulch.
When growth emerges next spring, feed with a light application of the fertilizer and again in mid-summer. When stalks have finished blooming cut them back to the base even with the plant. Plants form large clumps perfect for dividing throughout the garden.
Plant yours boldly in drifts adjacent to large marigolds like Antigua or Discovery. Lantanas like Lemon Drop or Silver Mound also look good with the Stokes' Aster. If you have been longing for a perennial to partner with yellow or orange daylilies then this is the plant for you. Plant them boldly side by side in informal large drifts of single colors.
While there is certainly nothing wrong with the natives, there are several great named selections. One of my favorites is called Purple Parasols (purple) but you will also like other varieties like Blue Danube (lavender blue), Bluestone (blue), Klaus Jelitto (light blue) and Wyoming (purple). But should generic be the only thing available, celebrate, because you will still have garnered one of the most delightful perennials for border.
Norman Winter is vice president for college advancement, Brewton Parker College, Mount Vernon, Ga., and author of "Captivating Combinations Color and Style in the Garden". Contact him at firstname.lastname@example.org. (c) 2010, McClatchy-Tribune Information Services.