'Wisley Primrose'
Yellow Sunrose
"The rainbow comes and goes,
And lovely is the rose."
-William Wordsworth
(1770-1850)
(1770-1850)
Helianthemum nummularium 'Wisley Primrose' is a recipient of the Award of Garden Merit. It has crepe papery flowers of pale yellow with darker yellow hearts.
Though each bright bloom is emphemeral, lasting only a day & unsuited to bouquets, it produces such a tremendous number of buds that it is perpetually under heavy blooms May to July, at which time it can be sheered a bit, inducing it to bloom again for August & September.
A creeping woody evergreen perennial, the silvered grey foliage can spread two or three feet or wider, mounding to eight inches or a foot tall.Sunroses do better in poor light soil than in rich humusy soil. They enjoy droughtiness but cannot abide poor drainage or excess moisture.
It will need a bit of watering during the hottest days of summer, & sheering in spring to keep it from getting leggy & wretched looking, but otherwise it demands no care. It seemed a splendid choice for our low maintenance water-conserving roadside sun-garden.
'Wisley Primrose' is frost hardy & retains its evergreen appearance through our mild winters that rarely if ever fall into the low twenties or teens Fahrenheit. Such winter-hardy varieties of Helianthemums are sometimes called Frostworts, Frostweeds, or Frostplants, because their silvery foliage makes them look frosted, & they retain their good looks even in winter.
It can survive temperatures to five degrees Fahrenheit, but would not be half so pleasant a winter shrub at the lower end of its tolerance, & might need hard pruning almost to the ground before spring's regrowth.
H. nummularium & other species of Helianthemum are the source of resinous labdanum used medicinally for millenia for such ailments as bronchitis & dysentary, as well as in perfumes & as an incense fumigant. The "labdanisterion" is a leather instrument which resin harvesters rake over the sun roses, the resinous matter adhering to the leather.