Skip to main content

Orchid Maintenance Up in the Rafters

Many species of orchids are epiphytic, meaning the live up in the trees. The University of Minnesota Conservatory greenhouse has one remarkable example of an orchid in this sort of habitat. This particular vanda orchid has lived for many years in a 3 x 3 ft wooden basket. In 2019 the plant was moved from the old greenhouse and hoisted up into the rafters of the tropical room of the new greenhouse. It has continued to grow to weight of approximately 50 lbs. The orchid has several branches growing out from the root ball, each branch measuring up to 3 feet in length.

After so many years of growth, the root ball has begun to rot and collapse. Today's chore was to help the greenhouse staff to assemble ladders and gather equipment to remove the old orchid and replace it with cuttings from the old plant, now in a new basket.

As the staff cut apart the old orchid, large sections of the orchid fell to the floor. The cuttings were free for the taking since they were to be disposed of in the organic waste pile. But, the cuttings came with a warning: the orchid was infected with an orchid virus. Any tool used on the plant was likely to infect any other orchid plant if the tool was not properly disinfected.

Plants, much like people and animals, suffer from a variety of infectious bacteria and viruses. Orchids are a host to more than 50 different types of viruses. The two most common are cymbidium mosaic virus and odontoglossum ringspot virus. These two are major sources of plant loss for orchid growers. Once infected, the virus spreads to all parts of the orchid plant. They are specific to orchids and do not infect other plant species. The signs of infection are yellow, brown, and sunken coin lesions on leaves and blossoms. Once infected, the virus cannot be removed from the plant. Not all infected plants will show active lesions, depending on the variety and health of the orchid plant. Prevention is limited to ensuring tools are properly cleaned before and after use.

Orchid cuttings in a new basket; the strap-like leaves of the vanda orchid are just barely visible at the edge of the basket. Arching over the basket are branches of a fig tree.

After helping with the orchid, I chose another chore from a list of tasks. There are four different display rooms open to the public (another four rooms are not open to the public without supervision). Each room represents a particular climate biome. Since they are frequently seen my the public, I chose to clean plant debris and weeds from the gravel beds in two of the four public display rooms. As I worked, I attempted to answer visitor's questions about plants in the collection.

Now clean gravel bed in the Mediterranean scrubland room

I'm always on the lookout for plants new to me. I noticed this bright red bell-shaped flower of wooly kohleria (Kohleria hirsuta var. hirsuta). The plant is native to South America and the Caribbean Islands. It is used to a warm dry habitat and prefers to scramble over rocky well-drained ground. I suspect the fine hairs help gather moisture and perhaps protect from insects.

Wooly kohleria (Kohleria hirsuta var. hirsuta); native to South America and the Caribbean Islands. Note the fine hairs on the leaves and flower edges.

Labels:

Comments

Post a Comment

Popular posts from this blog

I celebrate learning this about cycad plants

I didn't know that the cardboard palm - Zamia furfuracea - is a cycad. It isn't a palm tree (don't judge me, I'm not a botanist). But it also doesn't look like the other more familiar types of cycads with their fluted upright palm-like fronds. I didn't know it is said to be the second most commonly cultivated cycad, after Cycas revoluta . I didn't know this plant is unrelated to the common ZZ plant - Zamioculcas zamifolia - although they have a similar appearance. Before today I didn't know any of these things, but now I am happy to have learned them. From the parking lot I walked to the U of M Conservatory greenhouse in near-zero F weather. Stepping into the tropical spaces was a joy of its own. But being able to learn new information and experience new procedures was a compounding factor. Joy squared. During my 3-hour volunteer shift, my initial task was to clean the parasite critters (mealybugs and scale) from the stems and leaves of the cycad, Zami...
Post a Comment
Read more

The eponymous palm of Palm Springs

Tens of thousands of native California fan palms ( Washingtonia filifera)  rise over the gardens and streets of Palm Springs. The fan-like leaves flutter and wave as the trees gently sway in the desert breeze. If a plant could be described as elegant, this plant would certainly be one. Delicate fibers peel away from the leaf blade as they age, giving the palm part of its name, filifera . The advantage of the fibers to the plant is uncertain; however, the fibers were used by the indigenous Cuhuilla tribes for tools and fabrics. It is no accident the city is named for the palm. For centuries the native Cuhuilla residents were vastly outnumbered by fan palms. For the Cuhuilla, the plant became an important resource for their tools and shelters. Even today, I wouldn't be surprised if the number of palms outnumber the residents of the current modern city. Bird's eye view over old Palm Springs neighborhood; fan palms are everywhere. In their native environment, the palms grow best al...
Post a Comment
Read more

Another routine spectacular day in the greenhouse

It has been a sincere pleasure for me to volunteer a few hours a week at the University of Minnesota Botanical Conservatory. After many visits over the last few years, exactly none of those days have felt ordinary or repetitive. If there is a routine , it is that the botanic diversity of the collection - with over 3000 species - is displayed in a spectacular way each day. The Conservatory is located on the St. Paul campus, and is free of charge and open to the public during typical weekday hours. For instance, today most of my allotted time was spent in just one of eight rooms, the room that houses the tropical collection. The chores included pruning, re-potting, spraying, sweeping, etc. As I moved through the room, in every direction, there seemed to be a stunning plant pleading to be admired.  After the chores were complete, I had the opportunity to go back and photograph some of the beauties that surrounded me while working.  Dendrobium tangerinum , Papua New Guinea Dendr...
Post a Comment
Read more