By Alyssa Ford Morel, Extension Master Gardener
Few plants are more recognizable to even non-gardeners than English ivy (Hedera helix). Americans have had a long time to get acquainted with it since early colonists introduced this European and Asian native to North America in 1727. We kept planting it, and it started spreading, both by vining and by birds who eat the berries then poop them out elsewhere. Records show that it was spreading without human effort by the 1870s.
Compared to how long ivy has spread in America, conservation biology and our understanding of the damage that non-native, invasive plants wreak on local biodiversity is recent. In 1999, President Clinton signed Executive Order 13112 (amended in 2016 by President Obama), which defined invasive plants and animals as being non-native to the area in which they occur and cause “economic or environmental harm, or harm to human, animal or plant health.”
English ivy is one of America’s foremost invasives, taking over natural areas especially along both coasts. It aggressively colonizes both the ground level and the tree canopy, where it reaches sexual maturity and sets berries. Ivy on a tree blocks sunlight, which impedes photosynthesis, and adds weight that can topple a weakened tree.
Besides being invasive, ivy also hosts the Xylella fastidiosa pathogen, which is a serious threat to oak, elm, maple, and sweetgum trees, among other plants. While ivy does not support many native creatures, it does support rats, mosquitos, and ticks. People mistakenly think that ivy is good for erosion control, but in fact, ivy’s shallow roots do little to stabilize banks.
Nonetheless, our eyes are used to ivy and many homeowners cite its hardy evergreen nature as essential. The good news is that there are excellent native choices to replace it.
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Like ivy, golden ragwort (Packera aurea) is evergreen and takes either sun or shade. This vigorous spreader has yellow daisy-like flowers each spring. Homeowners on a budget can clear a small space in their ivy, and plant golden ragwort in it. The following year, the ragwort will have spread, and some can be dug up and transplanted to another space. Keep repeating until the ivy is gone!
Christmas fern (Polystichum acrostichoides) is an elegant choice for shade, with leathery fronds growing in arching clusters. Plants are between a half foot and two feet tall and increase in size over time. Unlike ivy, Christmas fern does prevent soil erosion, especially on slopes. Though the fronds look fairly ratty by late winter, pristine new fronds will emerge in spring, and the old ones will slowly decay, helping build the soil.
Hairy alumroot (Heuchera villosa) is a semi-evergreen plant native to southwestern Virginia that can take sun or shade. It puts up beautiful feathery flower plumes in late summer that support pollinators. It spreads both by expanding clumps and by seed.