Whole Lot of Hosta

By: Jon L. Peter, Curator & Plant Records Manager, Royal Botanical Gardens

Visitors to Royal Botanical Gardens often ask, “where are the flowers?” My answer will depend on the time of the season, but I often suggest to guests that they look beyond the eye-popping roses and coneflowers to the small inconspicuous flowers, like those of the spicebush, and the multitude of colours, patterns, and textures which can be observed in the foliage of plants.

The true superstars of foliage are plants from the genus Hosta. This is a very popular group of plants (just ask a hostaphile) which are generally grown for their leaf diversity. This member of the Asparagus family (Asparagaceae) is known as Plantain-lily but is commonly referred to by the genus name, Hosta. The genus was named by Austrian botanist and mycologist Leopold Trattinnick in 1812, in honor of Nicholas Thomas Host, the Croatian botanist and first director of the botanical garden of Belvedere in Vienna, Austria.

Hosta are rhizomatous or stoloniferous herbaceous perennials with upwards of 45 unique species native to eastern Asia. Since the mid-19^th century, they have been hybridized and mutations selected to produce more than 12,000 named and registered cultivated varieties (cultivars) and likely many thousands more which are not registered. Hostas gained popularity momentum in the 1980-90’s when a rush of new introductions became available. Many of those early introductions can be found in RBG’s collection.

At RBG, we grow more than 3050 individual plants across all our gardens, with 203 accessions representing 142 taxa (unique types) in the genus Hosta. We will be adding another 40 taxa to the collection this fall. You can find concentrations of Hosta in the Hosta Walk at Laking Garden and throughout the Rock Garden.

Now let’s bring this back full circle to the original question of “where are the flowers?” Since we generally associate Hosta with dramatic foliage, would you believe that Hosta can also put on quite an impressive flower display?

From spring to late summer, Hosta cultivars will begin sending up scapes of flower buds. I will admit that frequently the flowers are underwhelming shades of lavender or white but there are cultivars with flowers that have amazing fragrance, cool patterns, vibrant colours, and the flower scapes can range from short (sitting just above the foliage) to quite tall, which can help enhance the drama in the garden. Although Hosta are not native to North America, the flowers are frequently visited by native pollinators like bumblebees and even the occasional hummingbird!

In the curation of some of our gardens, I have realized there are two camps of gardeners. One which will remove the ‘ugly’ flowers as they emerge and the other which will enjoy the beautiful flower show. As we try to manage our garden spaces with decreased inputs and outputs, I have encouraged our gardening team to let the flowers remain and to even let them develop fruit and seed, adding length to their season of interest. Even though the foliage of Hosta will crash (wilt and die back) when exposed to a hard frost, some Hosta flower/fruit scapes will remain standing well into winter, providing another dimension to the winter landscape.

So, the next time a visitor asks, “where are the flowers?”, they may be surprised when I tell them to go for a mid-summer stroll through the Hosta Walk in Laking Garden.