Phenology Files: March 2023

phenology fi-ˈnä-lə-jē n 1 : a branch of science dealing with the relations between climate and periodic biological phenomena (such as bird migration or plant flowering) 2: periodic biological phenomena that are correlated with climatic conditions.

Osoberry: Harbinger of Spring

Early osoberry buds by pacificwhitesideddolphin on iNaturalist.

Winter on the Olympic Peninsula can take its toll on you. The hours of daylight are short, the sky tends to stay gray, the temperatures are low, and the plants are leafless. Every year, just as I begin to feel that winter will never end, there’s one plant whose lime green leaves tend to come before the rest and starkly stand out against the dull landscape. Osoberry (Oemleria cerasiformis) is a sign from mother nature that spring is well on her way.

This is why osoberry is one of the first native plants that I learned to identify as a young adult. Around February, osoberry seems to jump out from its dreary surroundings. Osoberry is found in a variety of landscapes, from wetlands to forests. It takes full advantage of the sunlight coming through the canopy before the larger trees get their leaves and produce shade. The young leaves smell a bit like cucumber.

Osoberry flowers by enspring on iNaturalist.

By early spring, beautiful clusters of drooping white flowers are produced. This tends to line up just as the bees are emerging from hibernation, which makes osoberry an excellent early season nectar source. Other pollinators like adult butterflies and hummingbirds utilize their nectar too. The plant also hosts several caterpillar species, and the leaves are a food source for larval butterflies and moths.

Female plants produce small fruits which start out a yellowish-gold color in the late summer and ripen into a bluish-black by the fall. Osoberry is closely related to stone fruits such as true plums, apricots and almonds and their fruit is edible. I have unfortunately never had the opportunity to taste it as it is a favorite for local birds. The early bird gets the fruit!

Osoberry fruit in late summer by pacificwhitesideddolphin on iNaturalist.

Every year, I am so grateful for the pick-me-up I get from spotting those early spring buds and think about all that the summer months ahead may hold. Who knows, maybe I’ll even beat the birds and get to try osoberry fruit this year!

From the desk of Lexi Wagor, Community Relations Manager