Thursday, May 13, 2010

Pinebarren Frostweed - Helianthemum corymbosum

Although not as showy as some of our wildflowers, I have always admired the simple beauty of our frostweeds - or "rockroses" as I first learned them; species in the genus Helianthemum.  Pinebarren frostweed (H. corymbosum) is perhaps my favorite.  It is found throughout Florida in upland, well-drained sandy habitats, and throughout the Southeast. 
Pinebarren  frostweed is an evergreen perennial that remains low to the ground throughout the year.  It rarely stands taller than about 8 inches, but slowly spreads outward to form a mound that can reach several feet wide.  As such, it makes an attractive mass of foliage when not blooming and always looks "tidy".  The leaves are linear, about an inch long, and alternate along the stem. 
Blooming occurs mostly in the spring, though a few flowers may be present at other times.  They are a wonderful canary yellow in color, about 1/2 inch across, with 5 petals and produced in numbers across the crown of the plant.  The contrasting orange of the anthers (the pollen-bearing parts of the flower) inside the floral "cup" lend an additional beauty to the blooms.
Pinebarren frostweed is easy to maintain in a landscape. It is extremely drought tolerant and thrives just about anywhere as long as its given good drainage and plenty of sun.  Because of its short stature, it should be placed in the front of a mixed wildflower planting or placed along trails so it can be fully admired while in bloom.  It would make a nice mass planting as well, but plant individual plants on at least 18-inch centers as they will spread outward in all directions.
Regrettably, none of the frostweeds are currently being propagated commercially in Florida - at least by nurseries associated with AFNN, the Association of Florida Native Nurseries.  We are hoping to change some of that at Hawthorn Hill.  We have maintained this species for several years now in our Pinellas County landscape and are preparing to collect seed from our plants for future propagation.  Let us know if this species interests you.  We hope to have a few seedlings by fall 2010.

2 comments:

  1. Hi.... can you identify this for me?

    http://www.projectnoah.org/spottings/24615225

    Looks a bit like a frostweed, but it was on a beach on Captiva Island, not upland as you described.

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  2. It is Beach evening primrose - Oenothera humifusa. The yellow flowers close up during the daytime - and take on that orangy coloration.

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