Renovation - What Happened to Plants

Renovation and Reconstruction of the Conservatory
What Happened To All Those Plants?

How do you move a 15-foot cactus with clusters of razor-sharp spines or a 100-year-old cycad that weighs nearly a ton? What equipment, vehicles, staff and expertise are required? Which of the more than 3000 plant specimens in the Conservatory should be kept, and what should be done with those that are not? These are a few of the questions the staff of the U.S. Botanic Garden addressed when they learned in June 1997 that the Conservatory was closing for a three-year renovation project.

Blue cycad bundled for transport

Euphorbia being carried from the Desert House

The Botanic Garden staff quickly developed a removal plan. The first step was to determine the fate of each plant in the Conservatory. To meet the selection criteria, plants had to support the Botanic Garden's mission and the future landscape plan for the Conservatory. With holding space at a premium, priority was given to rare, endangered, or hard-to-acquire species and notably large and/or beautiful specimens. Special attention was paid to plants of historical significance; for example, many can be traced back to the government-sponsored 1838-1842 Wilkes Expedition, which circumnavigated the globe, completed extensive surveys of the Pacific Ocean, and collected plant material that formed the nucleus of the collection at the Botanic Garden's first Conservatory. Furthermore, size was a factor: all plants would have to fit into the USBG production greenhouses, which have a maximum height of 20 feet. After years of caring for the plants, our staff found that performing an objective evaluation was no easy task.

Once selections were made, a removal team was organized. Staff from the Conservatory and Maintenance Divisions of the USBG and the Capitol Grounds were called into action. Staff from the Production Facility developed a plan to receive the plants as they were removed. Our plant recorder worked closely with the team to make sure that plants were inventoried.

Perhaps the most dangerous plant to move was Pereskia grandifolia, a primitive tree-like cactus from Brazil with thick green waxy stems bearing clusters of radiating needle-sharp 2-inch black spines. This 15-foot specimen, over 35 years old, had been pruned whenever it grew to the roof of the Old World Desert House. Over the years it developed a thick, woody base, giving it a distinctive character.

Its removal was fraught with danger. From years of trimming, the staff had gained a healthy respect for this plant's ability to inflict serious lacerations. The removal procedure was undertaken cautiously, beginning with cutting the plant back to more manageable size and wrapping it securely in plastic and a thick piece of carpet. A large root ball was created by digging around the cactus by hand with a sharp nursery spade. Two giant tap roots, between 4 and 6 inches in diameter, had to be cut with a hand saw. Once freed, the 400-lb plant was secured on a cart and rolled out to a truck for transport to the Production Facility. In all, the removal required three staff members and 1-1/2 days to complete.

Most dramatic was the removal of two giant Cycas circinalis, palm-like trees with a single trunk and large fronds. These stately trees, among the most beautiful specimens in the entire Conservatory, were in the Subtropical House behind the orchid display. Although their age was unknown, their size suggested they may well have exceeded 100 years. Unfortunately these 25-foot specimens were too tall for our production greenhouses. After much research and debate, a very innovative technique was proposed: take a 14-foot cutting and try to root it! The production staff had done it once before with a smaller cycad. Now the challenge would be to get a giant one to root.

But how to take the cuttings? Staff from the Capitol Grounds Tree Division attached a pulley to the top beam of the Subtropical House and wrapped a large strap around the cycads. USBG staff held ropes tightly around the base of the plant, while a tree crew member cut the 14-foot section using a chain saw. The 1200-lb cutting was carefully lowered using the pulley and placed on a chain-link fence cradle fashioned with two metal poles. A team of 10 employees rolled the plants on a cart onto the terrace, where they were lifted by a forklift onto a flatbed trailer. When the plants arrived at the production facility the Tree Division crew helped unload them and showed the USBG staff how to use arborist's knots to securely tie them to the columns in the greenhouse, where they will be potted. The rest of the process is now up to the plant.

Plants that were not kept in the Botanic Garden collections were offered to other educational and nonprofit institutions, providing they could send their own crews to dig and transport the specimens. Among the 22 recipients were the National Zoological Park, Capital Children's Museum, National Aquarium in Baltimore, Smithsonian Horticultural Services, American Fern Society, Brookside Gardens, State Arboretum of Virginia, and American Botanical Council. Some traveled as far away as Texas! In some cases, the plant transfer was part of a reciprocal exchange; in the future, plants will be given from their collections to us for the new Conservatory exhibits.

The entire removal process went quickly and smoothly, thanks to careful planning and the outstanding cooperation between the USBG Conservatory, Maintenance and Production Divisions, and the Capitol Grounds staff.