April and May are the two busiest months in the annual cycle of native Oregon herbs and shrubs. Changes are fast and dramatic, spurred by plenty of rain and long, often sunny days. Leaves burst forth in a blaze of bright green in spring whereas leaves change color and fade gradually in the fall. Plants grow steadily but more slowly through the late summer and fall dry season. Winter’s short days and falling temperatures bring slowing and, except the evergreens, a brief dormancy.
The usual latest frost of the growing season is near April’s end. It will take another six weeks for soil to warm up enough for optimal growth of garden plants like corn, peppers and beans. April is a good time to plant broccoli, carrots, radishes and beets. Be ready to keep the weeds down from the beginning of planting season.
Bumblebee queens emerge and begin foraging. Unlike honeybees, bumblebee colonies begin from a single, fertilized, hibernating female. This queen must find a nest and begin a new colony. She will start by laying eggs and feeding workers. When there are enough workers, she will stay in the nest and be fed by them while she produces drones and females at the end of the season. The mated females will hibernate to emerge as queens next spring.
The last heron nest of our East Delta Ponds rookery is gone. The solitary nest that survived the winter finally fell apart. Herons must build new nests in nearby trees.
David Wagner is a botanist who works in Eugene. He teaches moss classes, leads nature walks and makes nature calendars. He can be contacted through his website, fernzenmosses.com.