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Gardening in the Rainy Zone.
Penstemon 'Sour Grapes'
Sunset zones: 6-9, 14-24.
USDA zones: 7-10.
Height: 2 feet.
Width: 18 inches.
Early summer to mid-autumn.
Tubular, bell-shaped, deep purple flower.
Evergreen, large leaf.
Fertile, well-drained soil.
I keep penstemons on the lean side; they tend to live longer if not over-fertilized. Side-dress with compost or manures in fall, and fertilize in spring when growth begins, with a complete organic fertilizer.
Divide in late spring. | Softwood cuttings in spring.
Deadhead as flowers fade. Prune plants in late winter, or very early spring before new growth begins. I prune mine back to about 12-18 inches high.
Rainy Side Notes
Penstemon comes from the Greek words pente, five, and stemon, a stamen, referring to the five stamens.
Marjery Fish grew Penstemon 'Sour Grapes' in England. This hybrid has P. hirsutus in its parentage. The name 'Sour Grapes' comes from the way the flowers are bunched together. I would suggest the flower color is that of mouth-watering purple grapes, nothing sour looking about them. It looks best planted in groups of 5 to 7 or more. The evergreen foliage makes this plant a good choice for year round. In my garden this penstemon is long lived.
Penstemon 'Sour Grapes' is a good hummingbird and bee plant.
Photographed in author's garden.
Perennials indexed by botanical names. Click on corresponding letter below.