Did you know the Arboretum is open 363 of the 365 days of the year, rain or shine? It’s easy to love a garden on sunny days, but an overcast day can also be a profound experience. My scheduled visit fell on a rainy day, and it was filled with adventure.
At the entry garden near Highway 5, the tropical plants were glowing. The strong color combinations are richer in the dappled light of the gray day. The “color saturation” is deeper on overcast days in the way that trees and grass seem greener against the gray skies of a stormy day. You can see the mid-range colors and shadows much better than with the high contrast values of a sun-filled day.
Peace and quiet are additional benefits of a rainy-day visit. The Arboretum’s horticulture staff is busy throughout the gardens, but the space feels like your own tranquil space. The restorative soundscape created by the water on the leaves is calming. The fresh air is filled with the scent of petrichor, which occurs when rain strikes the soil and releases the bacterial compound geosmin. Using multiple senses: sight, sound and smell creates a meaningful experience in the natural world.
Quiet as a church, the tree canopy is reflected in the pavement near Berens Cabin parking lot.
The offspring of sandhill canes are called colts, because they have long legs and are ready to run soon after hatching. On the quiet day of my visit, the sandhill crane parents were foraging near the Chinese Garden (The Garden of Harmonious Beauty) with their colts. Different species are out and about during the ebb and flow of a rain event.
One of the sandhill cranes makes itself at home in the Chinese Garden.
Many organisms love rain, but lichens live for the rain. Lichens are poikilohydric; they can dry down into dormancy and then rehydrate when needed moisture is available. Lichens reveal brighter colors after a rain event when the lichen body, the thallus, is saturated with moisture and actively photosynthesizing. Twigs and small branches on the ground in the Arboretum often have lichens on them ready for close observation, such as this one, an eastern speckled shields lichen, gray and bright olive after the rain.
Eastern speckled shield lichen glistens after a short rain shower.
Bumblebees and other pollinators take shelter during a rain shower, but they are out soon after the last raindrop falls. At the edge of the Clotilde Irvine Sensory Garden parking lot, there is a good stand of bee balm, or monarda. The flat, upright shape of this mint creates an excellent place to observe bumblebees and other pollinators. This two-spotted bumblebee is resting on a leaf because the monarda was still too wet from the recent rain shower. I noticed that the bee would land on some of the flowers and avoid others. It turns out that bumblebees use electromagnetic fields through the hair on their body to determine if a flower has pollen and nectar, or too many raindrops.
(Left) A two-spotted bumblebee rests on a monarda leaf. (Right) A bumblebee crawls along the face of a sunflower.
Sunflowers are in full bloom at Farm at the Arb. These are a shorter variety, around 6 feet, so they will mature early by late August. This agricultural plot is another great place to observe and photograph bumblebees and other pollinators. The true flowers of the sunflower will swell and blossom from the outside edge to the center, displaying the Fibonacci sequence in the arrangement of the seedhead. Additional information on bees and other pollinators is just across the parking lot at the Tashjian Bee and Pollinator Discovery Center.
Bumblebees count on a free lunch from summer sunflowers at the Farm at the Arb.
Don’t forget, the Andersen Horticulture Library, the Gift & Garden Store and Rootstock are also open, rain or shine; hours may vary. Three-Mile Drive has many small parking spaces that allow you to stop and spend time along the route. Dress for the weather because a rainy-day visit to the Arboretum is a great time for discovery and reflection.
Zan Tomko is an artist, horticulturist, Minnesota Master Naturalist Instructor and a co-founder of the iNaturalist Minnesota Lichen Map Project. To learn more about the University of Minnesota Extension’s Master Naturalist program, visit their website.