Arum a joy for all seasons

Italian arum (Arum italicum) is a shade plant for all seasons. It was originally purchased from a nursery in Snohomish County, and the nurseryman warned us that it would be a mistake to transplant it in late spring and take it east of the mountains. Contrary to his warnings, our arum weathered both the transplanting and at least 10 of those Cheney winters.

I have just removed the leaves and stems from a healthy clump of arum because they die back after the formation of tight-rounded cone of tiny beadlike red fruit on short stiff stems. The fruit was preceded by callalike white to greenish-white blooms, covered by a thin skein as they emerged from their tubers. This covering dries off as the flowers become fruit. The fruit on fleshy stems will hold up for the remainder of the summer, turning orange as autumn approaches.

In late August to mid-September, new leaves will begin forming. These leaves are arrow-shaped, measuring as much as 12 to 14 inches in length and 6 to 9 inches in width. A stunning abstract mosaic pattern develops on the leaf, veining it with soft green-white lines. The foliage holds its color, patterning and shape through the winter. To prevent winter sun scorch and snow burn, we cover the leaves with pine needles. (The barren deciduous trees that shade the arum for three seasons leave it somewhat vulnerable to winter’s extremes.)

The Sunset “Western Garden Book” (p. 203, revised and updated edition, 2001) suggests that unspecified favorable conditions will allow arum to “naturalize by volunteer seedlings.” I’ve not been observant enough to note whether the clump our visitors praise has developed that way. The clump has grown in a well-mannered slow progression, making itself a fine companion to tulips and daffodils in spring, heuchera, hostas, pulmonaria, and brunnera throughout the summer, and hellebores in the winter.

Arum italicum is undemanding. A periodic mulch of compost will add nutrients. Removing the desiccated leaves in midsummer and cutting back the fruit stems in early autumn are the only tasks required of the gardener. During recent days of high heat, it received more watering than usual because its companions are less drought-tolerant.

Arum is a visually appealing plant as it proceeds through its annual cycle. Each season brings something of interest and pleasure to the garden. I think it may be time to divide some of my clump come autumn so others can enjoy this wonderful plant.