Skip to main content

Quercus (oak) maintenance

Making the rounds

Before starting my shift as a volunteer at the University of Minnesota Conservatory Greenhouse I enjoy walking around to see what plants are in bloom, and I also check on my prior projects to see how they have progressed over time. Today I noted the corpse plant was in full bloom.

It is a sure sign of spring when the corpse flowers are blooming (Amorphophallus titanum). From the tropical forests of Indonesia, it has one of the largest flowers in nature. When it blooms, the large red and green "flower" spathe may measure up to a meter in diameter. It has a scent similar to rotting flesh, the color is dark red like meat, and the central flower spike (spadix) heats up to body temperature. All of these features are helpful to attract insect pollinators.

Corpse flower (Amorphophallus titanum)

Oaks

There are several species of oak trees (Quercus) in the Conservatory's collection. For a long time 16 of them have been used as part of a research project. Located in a separate small greenhouse, all 16 oaks are to be repatriated to the Conservatory in the future. To do so they first need to be cleaned up, re-staked, and repotted in some cases. 

At some time in the past few months the 16 oak plants were the unintended bystander recipients of a fine spray of white wash. White wash is frequently used by green house managers to coat the greenhouse glass to act as a sunscreen for the plants.  As a result, many of the oak leaves were coated with fine white particles which are unsightly, and the powder is possibly causing the photosynthetic potential of the leaves to be reduced.

My chore for the day was to clean the white wash off the leaves, stake, and repot the trees as needed. In my three-hour volunteer shift I was able to clean and repot three oak plants. I figure the group of 16 oaks will take many more hours to prepare before moving them into the Conservatory. The three species for today were: Quercus douglasii, Quercus chrysolepis, and Quercus aristata.

Oak species waiting to be cleaned

Quercus douglasii is a native of parts of California. It is a large and long-lived tree known for being drought tolerant. It has the common name of blue oak for its leathery blue-green leaves, which have lobated edges. The leaves are deciduous. The pollen of the tree is highly allergenic. The acorns are an important food source for wildlife and livestock.

Quercus douglasii

Quercus chrysolepis, or canyon oak, is an evergreen oak native to western Mexico and the California coast. It also has flat leathery leaves with prominent spines on the leaf edge. It tends to be found along stream beds, hence the name canyon oak.

Quercus chrysolepis

Quercus aristata is another evergreen oak tree native to western Mexico. It grow no taller than 40 feet. It has stiff leathery leaves with sharply serrated edges when mature.

Quercus aristata

The orchids are still flowering this spring.

Cymbidium schroederi, native of China and Vietnam



Labels:

Comments

Post a Comment

Popular posts from this blog

A Sensitive Plant and Common Weed

Mimosa pudica, also commonly called the sensitive plant  was a popular houseplant when I was growing up in the 1970s. It was popular for its ability to quicky change shape by folding up its leaves to protect them from herbivore predators. At the slightest touch the plant is able to expell water from special cells in the leaves, changing the shape from frond-like to a stick-form. The plant creeps along the ground, never for than a foot or so in height. In tropical parts of the world this plant is considered and invasive weed. Today, as I was treating plants to remove pests I happened to touch the leaves of a Mimosa pudica , one with a pretty puff-like flower. Sure enough, the leaves all folded up to almost nothing. Mimosa pudica , the sensitive plant Other more routine chores during my four-hour shift at the U of M Conservatory included cleaning three plants of Hibiscus clayi, native to Hawaii. These three plants in particular have suffered repeated infestations with a variety of in...
Post a Comment
Read more

A Thames River Walk Through Time: Repurposing Tow Paths

I love it when old technologies are repurposed to solve entirely different problems. A perfect example is the extensive system of canals and tow paths throughout England. Before the Industrial Revolution and the advent of railways, these canals were built to transport goods between cities and towns. Narrow boats pulled by horses or mules along tow paths were a common sight. Today, however, these tow paths have found a new purpose: recreational walking. They offer picturesque routes through the English countryside, allowing people to explore the beauty of the canals and rivers. The commerce that once flowed along these waterways may have shifted to railways, but the paths themselves continue to serve a valuable function. This year, I had the privilege of joining three other hikers on a journey along the River Thames tow path, from the city of Oxford to its source, a distance of about 50 miles. Farther upstream, the river gradually narrowed, eventually transforming into a swollen creek b...
Post a Comment
Read more

Plantulary: Botanical Dance

The title of the dance performance was Plantulary. The theme, botanical. On a whim, my partner suggested we attend a performance of a new dance work by a small immersive arts collaborative, Aniccha Arts. Through the arc of a single year—from growth through to dormancy—the dancers describe the story of plant life using percussive dance rhythms, music, literary, and various vegetable props. For me, this dance performance was a challenge to appreciate; it was no Swan Lake. I didn’t fully understand the connection between many of the sound and dance elements. But, curiously, the memory of it has stuck with me for the past few days. To set the scene, the stage consisted of a simple dark room lit by spotlights and early evening sunlight coming in through large windows. Along the baseboard of the stage were narrow trays of green seedlings lit by fluorescent grow-lights, forming the outer limit of the performance space. To further imbue the stage with plant life, several moss balls (kokedama-l...
Post a Comment
Read more