City Gardener

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...

Walking has to be one of life's greatest joys. What better place to do it than a well-tended trail? The UK is blessed with an abundance of great walking trails, partly due to the historic laws which protect the public's rights of way to walk across private land. This year I had the opportunity to walk parts of the Thames Path which runs through London and up the river for 180 mile to its source. There, water bubbles up from a small spring out in the countryside. I've divided my walk into two blog posts, each focusing on part of the path: first through the London boroughs, and then from the city of Oxford to the source of the Thames. Thames Path through London There are many resources and guides describing the layout and topographical details of the Thames Path. Probably the most authoritative is the National Trails website . But, frankly if you only have a few hours in London then Google Maps will adequately display the trail along the river, including transportation optio...

More than 350 years ago a 4-acre walled garden was established on the north bank of the Thames river by the Worshipful Society of Apothecaries. The garden was used for the production of medicinal herbs by the members of the apothecary guild. Prior to the guild, the walled garden had been in private hands - which at one time included Sir Thomas More, who eventually lost his head for his opposition to Henry VIII. Three hundred years later the garden was finally opened to the public in 1987. In 2023 I had the privilege of visiting the garden shortly after the Victorian-era, teak-framed glass houses had been restored to like-new condition. Many of the plants were past-peak in September, but some color remained here and there. Senna corymbosa, long used as a laxitive St. John's wort, used to treat infections and inflammation Wide-angle view of offices to the far left, and glass houses on the right. Chelsea mansions stand in the distance. Plumbing and window crank detail in a glass house...

I felt the firm grip of fall as I walked the half-mile from the parking lot to the Conservatory Greenhouse at the University of Minnesota, where I volunteer. The temperature outside was in the 30s, and the wind whipped at my face. Yesterday there had been snow flurries.  In stark contrast to the outside world, the greenhouse climate was quite different. Part of the greenhouse is maintained at near-tropical temperatures. But other sections of the greenhouse are kept significantly cooler to support plants that have evolved in seasonal climates. Although indoors, autumn has arrived here too. The sunlight dims, and the nights grow long. Inside these cool greenhouse rooms the plants shed their leaves and virtually cease growth for the winter months, just as they would outdoors.  Part of my assignment for today included the pruning of yellowing and brown leaves. Removing the dead foliage from the plants and the floors helps to reduce the overall risk of mold and other pests affectin...

If you want to have a rotting good time then what could be better than the Superior Hiking Trail in October? As I walked the trails this year, I - now in my seventh decade - couldn't help thinking of the phrase "there are more days behind me than in front of me." The forest too has very few days of non-dormant life remaining in the year 2024. Much of the trail was obscured by the fallen leaves of various textures, yellowed and soft, or desiccated and brown. The birch trees stand as silent and bare witnesses to the passing of the summer. But along the path, there is beauty too, in the soft carpet of dead leaves, and the rotting logs extravagantly decorated with moss and mushrooms. Adding much more significance to the mere visual beauty of fallen logs is their ecological contribution to the forest long after they've fallen. Hundreds of species inhabit the logs on top, on the inside hollows, underneath, and along the sides. And, the collective biomass of downed trees and...

As a layman of botany the idea of carnivorous plants has perplexed me. The capturing and eating of other creatures seems like it ought to be limited to animals, since animals are mobile and plants are not. Almost all plants survive and thrive in the world through photosynthesis. They do not need to feed on animals to survive. But, what about the group of plants that are carnivorous? As stationary plants, why and how do they eat critters? This topic was stimulated by my assignment today at the Conservatory Greenhouse of the University of Minnesota. My task was to clean several large tanks of water filled with aquatic plants. While cleaning the tanks I realized many of the plants were classified as carnivorous . What is it about the aquatic environment that causes plants to eat - in effect - other creatures? The short answer is carnivorous plants evolved in nutrient-poor settings such as pond water which is naturally low in the amount of nitrogen needed to synthesize proteins. To compens...

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...