August lilies -- wallflowers worth noticing

Hosta plantaginea, sometimes known more romantically as August lily, is stunning. Its substantial, light- to medium-green leaves give rise to stalks that produce large, white, trumpet-shaped flowers that open during the lazy afternoons of late summer.

Unlike the unscented blooms of other hostas, plantaginea flowers have a lush, pervasive fragrance that some have likened to honeysuckle.

And, as if that isn’t enough, Hosta plantaginea has a reputation for slug resistance as well as the unique ability to send up fresh new leaves during the growing season.

By all rights, the August lily should be one of the belles of the horticultural ball, but it isn’t.

Tony Avent, hosta enthusiast, breeder, and owner of Plant Delights Nursery in Raleigh, N.C., says there is one big reason for this – “green leaves.”

While more popular hostas feature leaves emblazoned with splotches and edgings of cream, yellow, or chartreuse, plantaginea makes do with unadorned green foliage.

At this moment in the horticultural fashion cycle, plain green leaves are not chic, even when accompanied by knock-’em-dead flowers.

Hosta plantaginea’s relative lack of commercial success may also have to do with some of its other traits. Because it is native to southern China, the species does not need a cold winter dormancy period.

This is wonderful for gardeners in the southern United States, but difficult for those who live north of USDA Zone 6, where the combination of a cold winter and a dearth of insulating snow cover can kill the plants.

They also emerge from the ground relatively early in the spring, making them vulnerable to damage from late frosts.

Hybridizers, who usually seem able to improve on just about any plant, have been hard pressed to produce interesting leaves and cold tolerance, while maintaining plantaginea’s large white flowers and delicious fragrance.

Part of the reason is that hostas tend to be genetically unstable, says Mr. Avent, and plantagineas flower later than other hostas, rendering them inherently uncooperative.

To add to the breeders’ burden, one of the most desirable traits – large flowers – tends to disappear during the hybridizing process.

But hybridizers thrive on such challenges, and over the years they have succeeded in breeding strong plantaginea hybrids that are more cold tolerant.

Most of the hybrids have had purple flowers, but a few, like the groundbreaking ‘Royal Standard,’ a green-leafed hybrid introduced in 1965, feature flowers that are nearly white.

Fortunately, hostas are prone to producing “sports” or spontaneous genetic mutations. “The majority of new hostas come from mutations rather than breeders,” says Avent.

One such mutation resulted in ‘Ming Treasure,’ which has the same large, fragrant white flowers as its parent, with the added attraction of leaves with white edges.

And what did the arbiters of horticultural fashion think of this admirable plant?

“It didn’t catch on,” he notes.But nothing is as constant as change, and Avent thinks the plantagineas are due for a revival. “Back in the ’70s, Hosta plantaginea was all the rage,” he says, “and fashion tends to run in 30-year cycles.”