With springtime in full swing in Southeast Alaska, our meadows and forest shrub-layers are greening up as new leaves sprout from twigs and blades of grass poke up from the ground. However, in certain places around Juneau, curious-looking patches of yellow stand out starkly within a sea of fresh green growth. These bright spots are infestations of reed canarygrass, an extremely aggressive invasive plant that is found throughout Juneau and elsewhere in the region.
In late summer and early fall, canarygrass transfers energy from above-ground foliage to below-ground rhizomes. Come spring, this stored energy fuels the production of new stems and leaves which rise up through a dense mat of yellow thatch left behind the previous year. By early May, fresh green growth nearly obscures last year’s thatch.
Reed canarygrass is one of the first plants to emerge in the spring, and the last to die back in the fall. Getting an early start on the growing season is a common trait among invasive plants, one that helps these invaders get a leg-up on the natives which they outcompete for space, sunlight, and nutrients. Native plant communities that are lost to invasive plants has serious consequences for our local economy, subsistence resources, and natural beauty.
Why are some canarygrass infestations around Juneau still looking yellow in early June? SAWC restoration biologist John Hudson is waging war on reed canarygrass in wetlands and meadows around the community. In late September and early October of last year – shortly after native plants had gone dormant, John treated numerous canarygrass infestations which were still green and thriving.
Canarygrass’ extended growing season turns out to be its bane. Having succumbed to the herbicide, only yellow patches of thatch remain well into spring. Upon close inspection, however, you will see native plants, like cow’s parsnip and chocolate lily, sprouting up from below to reclaim their rightful habitat and restore lost beauty to our treasure open spaces.