Isodon Species, Trumpet Spur Flower

This perennial produces the most prolific and beautiful blue blooms in my part shade garden! It tolerates drought and is low maintenance.

One of the few autumn-blooming perennials for shade. This should be planted far more often.

In a friend's neglected garden...Read More, without irrigation for over a year, a well established plant grew healthily and produced profuse blue-violet flowers in October, in the tough dry shade of hemlocks. No seedlings.

Update: I've now grown this (in shade) for one season. Very showy when in bloom. Hundreds of inch-long, luminous blue-violet (or white) flowers in large open panicles clothe the plant from the base to the top. They glow like stained glass when back-lit with the low autumn sun, though in shade they tend to blend with the shadows. The show begins in early October and continues for about a month.

This is a see-through plant, with sparse slender foliage. The habit is light and airy, upright and reaching 3-4' tall, the stems slender and brittle. This isn't a specimen plant---three plants would look better than one. Without some support, it sprawls. It would look great interspersed with fall-blooming anemones, Aconitum carmichaelii, or dark-leafed bugbane cultivars.

A fast-growing clump-former. Emerges from dormancy late in the spring. Said to require protection from afternoon sun.

May be divided in spring. Cuttings root easily in summer.

Said to be deer resistant.

AKA Plectranthus effusus var. longitubus or Isodon longitubus.

Update 9/16: Stems are brittle and have been half-trashed by a rambunctious pet.

This plant has proven itself very sturdy even in tough, dry shade conditions. It has reseeded in abundance and I have dug up several to ...Read Moretransplant and give away. This shade of blue is a rare treat in October, and I recommend siting it with a backdrop of contrasting autumn foliage.