Robust Natives at Home |

Robust Natives at Home

Posted on September 4, 2018 by tadpolehaven

“Is it invasive?” — a common question gardeners ask me while plant-shopping. The word “invasive” gets bandied about a little too freely, in my opinion. I save the “I” word for non-native plants that have invaded our wild landscapes and pose a danger to the ecosystem’s balance. English Ivy suffocates trees and forest-floor plants alike; Purple Loosestrife gradually infests wetlands; Yellow Archangel smothers the forest floor: those are the evil genies that have escaped from their native habitats and flung off the constraints of their natural predators and ailments.*

Of course, some native plants are greedy for territory while some are fairly sedentary, content with their assigned space in the garden. Every plant in any native ecosystem has a niche to occupy that benefits the rest of the system. As gardeners, we do our best to provide a space for each plant that replicates, to some degree, the natural conditions each species has evolved to prefer.

Some plants have evolved to spread quickly, covering ground that has been disturbed by natural forces (fire, windstorm) or human forces (bulldozer, plow). Quick-spreading thicket-forming shrubs such as Nootka Rose (Rosa nutkana) and Salmonberry (Rubus spectabilis) prevent erosion and ready the land for trees such as Red Alder (Alnus rubra) and Black Cottonwood (Populus trichocarpa). Where winter storms have scoured the beaches, Coastal Strawberry (Fragaria chiloensis) recovers quickly, sending out rapidly-growing runners several inches at a pop, while the more mature plants anchor their roots deep in the sand. The rapid spread and evergreen leaves give cover to vulnerable dunes and limit erosion. Meanwhile, in the mature forest where the shade is too dark for many species, Redwood Sorrel (Oxalis oregana) happily thrives, its brittle white-and-pink rhizomes rampantly occupying territory until finding equilibrium with fellow native groundcovers. Even in dry areas of the forest, Redwood Sorrel has it made in the shade. The foliage efficiently photosynthesizes limited sunlight. The more moisture it has available, the happier it is, spreading its lush clover-like leaves flat to gather in as much light as possible, folding them down to protect them from rain damage.

These native plants act honestly according to their nature. They are not invaders in their own home territory; they are just doing their job, thriving in their natural niche. If someone plants them, expecting them to remain within artificial boundaries when it is obvious to the plant in question that more territory with favorable conditions is available, the personalities of the human gardener and the active native plant may clash. Understanding is called for on the part of the human (we are supposed to be the smart ones J). I prefer acknowledging the energy of these particular natives by describing them as vigorous, robust, rampant or perhaps even aggressive. Please don’t call them invasive – they are at home!