How does Garlic mustard Overrun the Woodlands

•  It starts out imperceptibly at the edges of forests where man builds paths. In the first year its baby rosettes blend in with those of many other forest natives as it thrives in both sun and shade.

•  It can pollinate itself and also attracts pollinators. After it flowers prettily in year 2, its seedpods go ballistic and expel prodigious numbers of large seeds (350 per plant but up to 8,000 for a big plant). Some seeds sprout nearby and others hitch rides on animal hooves, mouse paws, birds, people, vehicles and water to set up inconspicuous new colonies.

•  It germinates and blooms before forest foliage leafs out, elongating ¾” per day from March to bloom as early as April 15th in even cold areas. It reaches 3’-4’ tall quickly and it, thereby, shades out native spring ephemerals such as Trillium and even sturdy fledgling Oaks that normally emerge.

•  Its “allelopathy”, or its chemical inhibitors of nearby plants, helps it outrival even trees. Soil mycorrhizae, especially those necessary for other plants, diminish in its presence.

•  Its unfussy soil preferences—even industrial emissions seem to benefit it—inch it forward.

•  It arrived without bio-controls and resists many of the pests and diseases that bother native plants.

•  Deer won’t eat it, so as the deer consume its competitors, they open the soil for more of its seeds.

It dominates the forest understory, as colonies converge to outrival natives. Like the tortoise in the race with the hare, its slow and steady pace wins the ecological race. But at such a cost to diversity!

Left: Garlic mustard flower cluster with brown seedpods emerging Right: large leaves form a symmetrical pyramid

EXCEPT

Sometimes we enjoy growing imported plants that have taken over in the wild. A wonderful example of this is the Common orange daylily, Hemerocallis fulva. These non-natives have naturalized and spread in woodland edges and by the sides of roadways and mark the real beginning of summer. Although these appear to take-over and although their tough fibrous rhizomes resist easy removal, they can be dug out and they will co-operate with other plants. Before they bloom, the nearby bulbs emerge and flower and as they go dormant, other plants seem to continue to grow. It may be a beauty but it’s not exclusive and plays well with others.

Left: Here they co-operate with Roses and Clematis Right: And its blooms are hard to resist!