Arum italicum: the backward plant

In my garden, the middle to end of September is marked by Arum italicum, or Black Calla, making its appearance. My name for this arum is "backward plant" for it emerges just as most everything else is going dormant. I have never reached a conclusion on just what this plant gains from beginning its cycle in September and growing all through the winter. I do know what my garden gains, and that is the beauty of arum foliage during a bleak time here in the mid-west.

The emergence of black calla is fascinating to watch from day to day. At first there are small green noses that quickly become slender green tubes standing on end above the soil line. When those tightly-rolled tubes reach about six inches tall they begin to unroll into leaves at the end of stems reaching down into the soil and the tuber. There are several hybrids and cultivars, and mine has deep green highly polished leaves with prominent heavily quilted veins. The leaves somehow manage to appear as though elves spent the night giving them a wax job. All through winter the arrowhead-shaped leaves continue to grow reaching up to 12 inches across and 18 inches in length. As they reach full size, blooms will appear in May.

When you see the hooded blooms, generally somewhat hidden in among the large leaves, you will recognize arum's relation to Jack-in-the-Pulpit. Blooms resemble pale green colonial candle reflectors with the small candle located just inside the hood. Scent somewhat resembles stagnant pond water, so mosquitoes are the pollinators, and yes, you do want the insects to do their work so the hoods turn to fruit.

As blooms are pollinated the leaves quickly fall over and melt away with tall stalks emerging where hoods once flared. At the top of each stalk large clusters of orange-red berries put on a colorful polished show during late summer. Once fully mature, the seed stalks fall to the ground providing midnight snacks for small mammals. For a short period the area is bare and then here comes the arum again.

Arum italicum are not fussy, but they can be slow to establish. From seed they require 5 to 7 years before maturity and bloom, so locating starts from divisions provides rewards far faster. Mine are inside the root system of a mature tree in stony soil with open shade. In a second location they are long a limestone ledge in decent soil.

My favorite companions are hardy begonia that come into foliage as the arum leaves melt away. When the begonia begins to bloom the arum seeds are falling over. Tricyrtis picks up the show after the begonia. Ferns make great companions as well. Heuchera villosa species, along with Helleborus foetidus, provide green in winter so I have a 12 month display.