City Gardener

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 insect

My assignment for today was to tie back the drooping branches of three different species of trees: the frankincense tree, the pincushion hakea, and the ben-tree,  Moringa peregrina . For tools I had zip ties, plastic tubing and nylon cord. It was not glamorous work, but necessary for the future growth of these small trees. Otherwise they would continue to grow in misshapen forms. Afterwards, I took a few more photos of this parachute flower, Ceropegia sandersonii , which I wrote about in my last blog post. Parachute flower, Ceropegia sandersonii 

Nearing the end of August, we're on the downhill slope of summer in Minnesota. Today is the beginning of the great Minnesota get together - the Minnesota State Fair. I am not a frequent or enthusiastic fair-goer. Large crowds and long lines make me feel anxious. I mention it only because the fairgrounds are adjacent to the University of Minnesota St. Paul Campus, where I volunteer.  Today on my bicycle ride to the greenhouse I passed hundreds of cars headed to the parking lots near the fairgrounds. Cycling faster than the traffic was easy since the streets around the fairgrounds were largely grid-locked with cars inching along. Thankfully, the drivers maintained their cool and avoided the temptation to drive in the bike lane - as witnessed last year. I was able to scoot past them and arrive at the greenhouse intact. My main assignment was climb up on a ladder and use a standard garden hose to spray the leaves of four small trees. The goal was to dislodge insect pests of various typ

It was an honor and a pleasure to spend the first hour of my volunteer shift attending the doctoral dissertation of now-Dr. Alex Crum. She was the first person to show me the ropes of watering plants at the University of Minnesota's Conservatory Botanical Collection. In July 2021, as the covid-19 lockdown was beginning to end, and volunteers were allowed back into service at the greenhouse. I was happy to be one of them. Dr. A was gracious and patient with my first day of instruction as a volunteer. Since then, Dr. A has completed her Ph.D. thesis, studying - the the best of my understanding - the chemical and ethnobotanical details of the compound betalain. This red-colored chemical is made by a limited number of plants in the plant kingdom - specifically, they are made in the carnation family of Caryophyllaceae. But when betalian is present, those plants tend to be used by humans all over the world for medicinal purposes. Examples of betalian-rich plants include amaranthus (anti-

Today I returned for my volunteer shift at the greenhouse of the Conservatory Botanical Collection at the University of Minnesota (St. Paul Campus). My assignment was to tend potted vining plants. In pots of various size, ranging from 6 to 24 inches, the vines have been trained to grow up onto either cables or trellises for support. During my shift, which today lasted three and a half hours, I was able to clean and prune approximately a dozen of the vines. Since the vines are growing on supports which cannot be moved or taken down, one of the challenges is to reach the top of the vine for cleaning and pruning. Many of the vines reach heights of about 10 feet off the floor. Necessarily, a tall ladder had to be used to access the growing business end of the plants. I was able to arrange a couple of side-by-side ladders so that I could balance a bucket of soapy water on the top of one ladder, and myself on the other ladder. Some of the vines were quite soiled by sooty black mold and scale