HUNTSVILLE, AL . . .
Dear Harvey,
The distinctive evergreen foliage of Italian arum
My brother asked if I could identify this plant for him. It is growing at his lake house under a canopy of tall oaks. Any ideas? Thanks so much, Beth W.
Dear Beth,
It looks like a bird left your brother a present in the form of a very interesting evergreen groundcover known as Italian arum (Arum italicum AIR-um ih-TAL-ih-kum) a member of the Araceae family and let's say a third cousin (or maybe second cousin once removed, I never can get that straight) of our native wildflower Jack in the Pulpit (Arisaema tryphyllum). As you can tell by the common name, Italian arum is not a native to the US but hails from southern Europe and has been grown here since the early 1900's.
I called Italian arum an interesting evergreen groundcover because of several features. One is the foliage of the plant with its distinctive green and white markings on arrowhead shaped leaves like those of caladiums and elephant ears. The leaves are eight to twelve inches long and first emerge in early autumn each year and stay evergreen throughout our winter months. This is a great feature in that most woodland plants are dormant at this time of the year and having an evergreen groundcover for winter interest adds diversity to the landscape. Since this plant is hardy to Zone 5, it is a bit like having a hardy caladium growing in the woodland garden.
I call this plant an evergreen (because of the foliage being visible during the winter months) but the life cycle of the plant is another interesting feature of Italian arum. After growing through the winter, the foliage remains through spring and then a single flower stalk emerges from the center of the plant. The flowers are white and are made up of a spathe (outer bract) and spadix (inner portion with the male and female flower parts. The spathe surrounds the spadix like a sheath just like we see with caladiums, elephant ears, peace lilies and Jack in the Pulpit flowers. After the flower emerges the foliage dies back going dormant from late spring through summer until re-emerging in the fall. The flower is pollinated and now the single stalk becomes a cluster of orange berries standing solitary in the woodland garden. Another common name for Italian arum is Orange candleflower for the time the fruits are visible on the plant. The fruits mature and fall to the ground, then germinate thus allowing colonies to form and patches of Italian arum to grow and spread. Birds also enjoy the fruits and as birds are want to do – they spread seeds to other spots, often far away from the mother plant. I believe this is what has happened in your brother’s garden – a bird has dropped a seed and a new plant germinated this fall and is showing out in the winter landscape.
If your brother becomes a fan of the Italian arum I would encourage him to gather the fruits in late summer, clean the pulpy, orange mass from the seeds and sow the seeds in the area around the mother plant. This will result in new plants coming up and creating a larger mass in the landscape. They would prefer a rich, organic soil with lots of leaf litter but they are able to tolerate wet soils and even dense shade (primarily because they go dormant during the summer months). Two other nice features are that insects do not seem to infest the plant and deer leave them alone – that is a great reason to add them to the garden right there. One reason deer may not like them is that all plant parts are toxic so be very careful when working with the plant. Doubtful anyone would eat the berries but the foliage can produce a sticky sap that can be a skin irritant similar to poison ivy. I really like seeing the distinctive evergreen masses in a stark winter landscape so hopefully this has helped to brighten up a dismal spot in your brother’s garden.
Tips of the Week:
• Prune fruit trees, especially apple and pear trees in the home orchard
• Be sure and use the right tools when you prune – electric hedge trimmers and chain saws are not always the best choices
• Now is a great time to do a soil test if you have not done one in several years – this will let you know if you need to apply lime before your fertilizer applications begin in spring
I look forward to answering all of your gardening questions. Please send your inquiries via email to hcotten@hsvbg.org. For those of you who prefer regular mail, please send to Harvey Cotten c/o The Huntsville Botanical Garden, 4747 Bob Wallace Ave; Hsv, AL 35805. The Garden's website – http://www.hsvbg.org