GARDENING

Hostas, grown primarily for their foliage, have been a popular border plant on the prairies for decades. Forming graceful mounds, their leaves are large and textured. In blue, yellow or green, they are often variegated with white or cream. There are over 50 species and thousands of varieties, with new introductions every year.

All are native to Japan, China or Korea, where they have been cultivated for centuries. In the early 1600s, Engelbert Kaempfer, a physician with the Dutch East India Company, working in Japan, made what was probably the first botanical drawing to reach Europe of Hosta lancifolia. By 1789, seed of H. plantaginea, native to China, had been sent by the French Consul in Macau (then a Portuguese Territory) to the Jardin des Plantes in Paris.

Many of these early introductions, presumed to be species, were in fact garden hybrids. By 1839, three varieties of hosta were listed in the American Flower Garden Directory. Today, it is not unusual for prairie garden centres to carry 30 or more varieties.

In the past, many of the variegated varieties arose as seedlings or sports (side shoots with a different leaf color and pattern from the mother plant.) But more recently these have appeared in the process of tissue culture propagation.

Leaves of hostas are generally heart-shaped but can also be round to oval or long and narrow. The tips may be round or pointed. The margins or leaf edges lack indentation such as teeth or lobes but may be wavy or undulating. The leaf veins are deep and prominent. The leaf surface can be smooth, shiny, flat or puckered.

Hosta flowers emerge through the foliage on a scape directly from the crown. Relatively large, they are funnel or bell-shaped, flared at their mouth and with six lobes. They are white, lavender or purple and consist of six stamens and a single stamen.

Hostas are easy to grow. In the wild, hostas are found in the shade in or on the edge of forests in evenly moist or well-drained soil well amended with organic matter. Although some are adapted to sun, most require light or dappled to full shade. Mulch the soil surface with 4 inches of mulch (e.g. post peelings, wood chips) to retain moisture and discourage slugs (Note: the coarse nature of the post peelings rasps their tender body parts). Most hostas are hardy and long-lived on the Canadian prairies. Slugs can be a major problem for hosta growers, particularly during wet summers. The term “resistant” doesn’t mean immune. If slugs are high enough in number they’ll eat just about anything. But given a choice, they are less likely to eat the hostas listed below. Why are these less palatable to slugs? Because their foliage is thicker, more textured and leathery. Slugs don’t like their meals overly tough. Hostas with greater ”substance” (read ”thickness) to their foliage appear more resistant.

Among the hostas that have proven slug resistant are H. sieboldiana var. elegans, ‘Sum and Substance, ‘One Man’s Treasure’, ‘Devon Green’, ‘Praying Hands’, ‘Sleeping Beauty’, ‘Stepping Out’, ‘Dorset Blue’, ‘Blue Mouse Ears’, ‘Abiqua Drinking Gourd’, ‘Afterglow’, ‘Aladdin’s Lamp’, ‘Amber Tiara’, ‘Halcyon’, ‘Hadspen Blue’, ‘June’, ‘Great Expectation’, ‘Blue Umbrellas’, ‘Invincible’, ‘Krossa Regal’ and ‘Big Daddy’.

Before planting, carefully inspect new plants for slugs or their eggs (clusters of small white translucent balls). Check the pots as well as the soil. In the garden, handpicking works if carried out with determination and consistency at dawn or dusk. Drop the slugs into a container of soapy water. Lure slugs with a “beerless” beer trap made of yeast, sugar and water in a saucer at soil level. Use slug baits containing iron phosphate to inhibit their ability to eat, causing death within a day or two. Apply diatomaceous earth.

Next week: Hostas – So Many to Choose From

Sara is the author of numerous gardening books, among them the revised Creating the Prairie Xeriscape. Her most recent, with co-author Bob Bors, is Fruit for Northern Gardens, available from most bookstores and garden centres.

This column is provided courtesy of the Saskatchewan Perennial Society (SPS; www.saskperennial.ca; hortscene@yahoo.com; www.facebook.com/saskperennial). Check out our Bulletin Board or Calendar for upcoming garden information sessions, workshops, tours and other events.