Wednesday, September 16, 2015

Stoke's Aster - Stokesia laevis

Stoke's aster (Stokesia laevis) is a very showy species that is widely propagated throughout the south in both wildflower gardens and in more formal settings.  It has been adopted by the plant breeders and many horticultural varieties are offered in garden catalogs.  All this is justifiable as Stoke's aster has all the natural attributes that make it a valued addition to the landscape.
As a Florida wildflower, however, it is quite rare, found in only 9 counties scattered in extreme north Florida. The largest population occurs in the Apalachicola National Forest. The plants photographed above were taken along a Forest roadside on 13 August.  Stoke's aster occurs naturally throughout much of the Southeast Coastal Plain, from Louisiana to North Carolina.  Throughout this range, it prefers moist and sunny locations - savannas, the upper edges of pitcher plant bogs, and roadside depressions.
Stoke's aster is an herbaceous perennial that dies back to the ground during the winter. Its large thick, strap-like leaves emerge in spring and form a rosette at ground level that may be 12 inches or more across.  The leaf surfaces are "hairy" and densely glandular; the leaves also often have spine-like teeth near their base. The flower stalk soon emerges from this leaf rosette and reaches its mature height of about 18-24 inches by mid-summer. Each stalk produces one flower at the top, though individual plants may produce more than one stalk.
The extremely showy blooms are what has made stoke's aster such a favored landscape plant. When fully open, each is 2-3 inches across and light lavender/pinkish blue in color. As a member of the aster family, these blooms are really a composite of a great many small tubular flowers and the large numbers attract the attention of pollinating insects of all kinds. Stoke's aster is an exceptional addition to a pollinator garden. Flowering is most common from June to August when few other asters are in bloom. Individual flower heads remain open for about a week.
Though Stoke's aster is offered by a great many garden catalogs, it is not an easy wildflower to keep in the Florida landscape unless attention is paid to its growing requirements. For one, I (and others I know) have had very limited success in my Pinellas County landscape with stock that does not originate from our Florida population; the garden catalog individuals and the plants I've purchased from "native plant" nurseries who've acquired their stock from sources originating outside Florida, have not survived long. This may not be as important for those of you that live in extreme north Florida. Stoke's aster is drought tolerant, but it will decline and eventually die if kept too dry for too long. It performs best in moist, but well-drained soils. Do not plant it in "heavy" soils, high in clay or organics. It also performs very poorly if not given ample sunlight; they will not flower and they will become thin and weak by the second season.
Given the right stock and growing conditions, Stoke's aster makes a wonderful addition to the home landscape. It is a species Alexa and I always include.

1 comment:

  1. It is my experience that Stokesia likes frequent division. Old clumps decline; divided clumps take hold and thrive.


Please let me know if this site and the various postings have been useful to you.