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About Eugene weekly. (Eugene, Oregon) 1993-current | View Entire Issue (March 27, 2003)
BY RACHEL FOSTER Life After Ivy A few yards from our front door is a bank of English ivy. The ivy does a good job of covering a steep drop- off from the road above and it makes a pleas- ant, green back-drop to my heavily planted front garden. We never have to water it and thanks to browsing deer (can ivy really be good for them?) it needs trimming only about once a year. There is just one problem: English ivy (Hedera helix) is so invasive in the Pacific Northwest that it has been on Oregon’s Noxious Weed List since 2001. In 2002 it made the Quarantine list, which means it is now against the law to import, sell or propagate the species in Oregon. (All but four named cultivars are exempt, however.) Ivy has been widely planted because it is a very effective and reliable groundcover: It grows in sun or shade in almost any soil, it suppresses weeds well, and its fertilizer and water requirements are quite low. Those same qualities make it a formidable pest in natural areas. There is a powerful argument for re- moving ivy from public places, especially where it threatens trees (which it eventually kills by shutting light out of the canopy) or where it is invading native plant communities we can ill-afford to lose. The ongoing project to remove a smothering coat of ivy from the forest in Hendricks Park has been tremen- dously exciting to watch. Last spring, wild flowers appeared in cleared areas as if by magic. But when homeowners ask me if I think they should remove ivy from their own property, my answer isn’t always yes. If you are an active gardener, by all means go for it. You’ll see the space it opens up as an opportunity. But if your ivy covers a large area or a very steep bank, or if you are not much of a gardener and you don’t want more work than you are doing now, I’d take some time to think about it. Just see that it doesn’t spread onto neighboring property, don’t plant any more, and make sure your ivy does not bloom. Ivy is distributed primarily by seeds, distributed by birds that eat the fruit. Ivy growing in shade, if trimmed regularly and not allowed to climb trees, can go for years without fruiting. But when you see wiggly, upright shoots with simpler leaves rising out of your ivy bank, that’s the sexu- ally mature form of ivy, and it is trouble. OK, you’ve de- cided your ivy has to go. What should you replace it with? While there are a few con- ventional groundcov- ers you might consider, the bad news is that I can think of no single alternative that will be equally effective in every situation where ivy flourishes. What is more, pretty blue-flow- ered periwinkle (Vinca minor) is also on the Noxious Weed list (though not yet quaran- tined), and I suspect other popular ground- covering plants may follow. Groundcovers, by their very nature, are invasive. A few low- growing evergreen shrubs are both effective and non-invasive. But since you are doing all this for the environment, why not go one step further, and take this opportunity to plant a native garden? I’d begin by mulching heavily to prevent a weed invasion while you think about it. When the mulch has decayed somewhat, you can fork it under to improve the soil texture a little. Replacing ivy in shaded, ordinary soil is easy: Maianthemum, wild bleeding heart, oak fern and wood sorrel will all spread vig- orously to form extensive colonies. They do lose their leaves in winter, so you may want to mix in evergreens such sword fern, salal and Oregon grape. Osoberry and native red- flowering currant are easy, taller shrubs with early spring bloom. Native strawberries are evergreen, and shiny-leafed coast strawberry LOOKING FOR CHOICES For a protocol for ivy removal, see the brochure “English Ivy: The Hazards and Removal Strategies,” available from Walama Restoration Project (484-3939) or download it from their website: www.walamarestoration.org An excellent guide to native plants that can be used in place of ivy is available from Hendricks Park (682-5324). The new native garden there may give you some ideas, too. Workshops in native plant gardening are offered each spring through Mt. Pisgah Arboretum. Contact the education manager at 747-1504 532 Olive St. 342.6820 2498 Willamette 349.0556 Mon-Sat 10-6 Sun 10-5 Since 1977 Spring is Here! The Plants are Ready, Are You? Great Selection of Perennials, Herbs, Veggies, and much, much more! Rose, Flower & Bulb Fertilizer 15% OFF All Sizes Summer Flowering Bulbs 15% OFF now thru April 6 th Worm Bin Composting Seminar, Sat. March 29 th , 11 am. at Olive St. with Zorba Frankel of Worm Digest “Quality Products For Natural Living” 28 MARCH 27, 2003 Fruit and leaves of mature English ivy. RACHEL FOSTER Popular, invasive species does have alternatives. (Fragaria chiloensis) is sun- and drought-tol- erant but also grows well in light shade. For areas where you would like to add other perennials for variety, I would stay away from over-vigorous spreaders. Maianthemum and wood sorrel, while fine around shrubs, are quite invasive in the sense that gardeners usually use the word, meaning they can infiltrate and eventually overwhelm other non-woody plants. Inside-out flower (Vancouveria hexandra) is a less aggressive (and deciduous) spreader. Fringe cup (Tellima grandiflora) is clumping, evergreen and easy. Rocks, of course, add visual interest and eventually become mossy. A combina- tion of rocks, ferns, a few clumping perenni- als and patches of, say, wood sorrel would be enough to make things interesting. Woodland soil is crumbly, with a high or- ganic content. If you have it, or can make it, the list grows longer. You can grow wild gin- ger, bunchberry and the lovely evergreen form of inside-out flower (Vancouveria pla- nipetala). You can have spring flowers from summer-dormant woodlanders like fawn lily and trillium. Tiger lily and Oregon iris should thrive at the sunny margins. Add a little year- round structure and greenery with evergreen huckleberry and longleaf Oregon grape (Berberis (=mahonia) nervosa). Kinnikinnick is often cited as a good ever- green, native groundcover, but I have had some failures with it. It needs sun, excellent drainage and some summer water to stay healthy in the Willamette Valley and it barely survives browsing deer. In sunny areas that are not too steep, a water saving solution might be a mix of gravel and rocks, with na- tive sedums and Oregon iris tucked up against the rocks and some patches of nootka rose and Oregon grape. My favorite Oregon grape for sunny places is the compact form of tall Oregon grape (Berberis aquifolium ‘Compacta’). Early nectar-sipping wildlife will thank you. ew EDITOR”S NOTE: EW’s annual Spring Planting Guide will not be in print this year, but can be found online at www.eugene- weekly.com/springplantingguide/index.html
