Caring for the Nation's Sculpture Garden

by Stephen Kelly, regional editor

Willie Townes use his expertise to repair a broken irrigation head. Irrigation is a continual maintenance task. Visitors and small animals, usually squirrels, can wreak havoc on PVC and drip irrigation pipes. There are 32 irrigation zones for the garden and a Rain Bird system of turf and garden heads are used. Mr. Townes uses one of five electric Club Cars to tow a trailer that holds and organizes irrigation repair parts. The turf at the garden is tall fescue with a small amount of rye blend. There?EUR??,,????'???s a limited use of pre-emergents, sometimes Roundup, something as basic as Weed-B-Gon, or a 2,4-D product.

The youthful National Gallery of Art on the Washington, D.C. Mall opened in 1941 with 121 paintings from the Andrew Mellon collection. Today it encompasses 100,000 pieces and 3,000 paintings spanning seven centuries of art, including the only painting by Leonardo da Vinci in the Western hemisphere, Ginevra de Benci (1474). Abutting the Gallery?EUR??,,????'???s West Building through rows of linden trees is the entrance to the Gallery?EUR??,,????'???s Sculpture Garden, beginning with the centerpiece fountain (skating rink in winter) and 6.1 acres of manicured gardens setting off 17 sculptural works.

I recently spoke with the people responsible for caring for the garden, Dianne Cina (chief of horticulture) and Jim Kaufmann (Sculpture Garden manager). I learned Kaufmann has a BA in horticulture from Temple University and is an ISA certified arborist. He worked at Villanova University for a year and has been with Gallery for just over 10 years. There is a 16-member horticulture crew, though he relies on two gardeners for the most part. There are eight gardeners, some have an interior garden to take care of, others have responsibility for areas around office buildings; some do greenhouse work (eight greenhouses on site). Those jobs may take them half the day, at which point they help out at the Sculpture Garden. ?EUR??,,????'??That?EUR??,,????'???s basically all the help we get. It?EUR??,,????'???s not a heck of a lot,?EUR??,,????'?? Kaufmann confesses.

The budget within the division is regulated by Dianne Cina. ?EUR??,,????'??We keep it (the budget) pretty tight,?EUR??,,????'?? she explains. Some costs are incurred for outside contract work (like weeding) or some arbor care, but ?EUR??,,????'??regular pruning, regular care, even cabling and bracing we will do in house,?EUR??,,????'?? says Kaufmann.

 

Derrick Williams (left) and Ron McGill prune the ?EUR??,,????'??Blue River II?EUR??,,????'??? hibiscus back to a height of 6-8 inches for the winter, after they start to go dormant. A clean cut is made with sharp, clean pruning shears placed above and angled down and away from the node between the leaf and stem. Once they start to grow, the plants are left alone except for removal of the spent flowers and broken branches.

Snow in the Sculpture Garden makes for special effects. Snow removal equipment includes one 72?EUR??,,????'?? Western plow, one 72?EUR??,,????'?? Sweepster broom mounted on a New Holland TC33 tractor with loader and one Toro snow thrower.

Dianne adds her staff has been taking care of the ring of linden trees around the fountain the past two years, which previously was contracted out.

Sometimes the initial landscaping around a sculpture piece gets modified as the garden matures. For the pyramid sculpture, Cina explains, three rows of cherry laurel were planted to keep people from ?EUR??,,????'??cutting through.?EUR??,,????'?? The tree ?EUR??,,????'??block?EUR??,,????'?? was effective, but as the laurels matured the horticulture department was asked to remove the back row of trees, as it was now blocking the base of the pyramid and the full view of the art work. A number of row of hedges were also planted, again to keep people from walking through certain area and some of these back hedges will also be removed.

Mary Braden, a volunteer, weeds reblooming Irises. The Irises can bloom until December and are fertilized with a granular 5-10-5 throughout the growing season,?EUR??,,????'?? says Kaufmann.. After they are done flowering the plants are pruned and divided. As power trimmers are not allowed for the grass around the sculptures a growth inhibitor (Embark) in diluted form is applied. The sculpture is ?EUR??,,????'??Cluster of Four Cubes,?EUR??,,????'?? a 1992 stainless steel design by George Rickey.

Mike Peters ensures that a bed of freshly planted chocolate cosmos (Cosmos atrosanguineus) receives an appropriate amount of water. This plant is a marginal perennial which must be dug out and stored over the winter.

Jim Kaufmann aboard a rented personnel lift to hedge a ring of little leaf lindens (Tillia cordata ?EUR??,,????'??Greenspire?EUR??,,????'???). ?EUR??,,????'??Due to last years pruning success, we are planning to perform this operation in May of this coming spring,?EUR??,,????'?? he explains. ?EUR??,,????'??Our hopes are to remove the first flush of growth to maintain a flat and neat appearance. Although this is not the most horticulturally proper exercise, the aesthetic results will be consistent with the intended design.?EUR??,,????'??

T & O

The turf at the National Sculpture Garden is tall fescue with a small amount of rye blend. Kaufmann notes a very limited use of pre-emergents, sometimes Roundup or something as simple as Weed-B-Gon or a 2,4-D product.

Kaufmann says he?EUR??,,????'???s pleased with the benefits of using the growth regulator and uses it in a diluted amount that the conservation department has tested so that no residue from the product will damage the sculptures. Other T&O products used as needed include Merit, horticulture oil and Distance (formulation for fire ants).

Dave Gentilcore removes a limb from a mature American elm (Ulmus americana). ?EUR??,,????'??To maintain a defense against Dutch elm disease we prune elms only after a frost has killed the bark beetle vector,?EUR??,,????'?? says Jim Kaufmann. Mr. Kaufmann, Willie Townes and Derrick Williams have taken the climbing skills module through ArborMaster Training, one of 11 training courses, all which emphasize skill, safety and productivity.

Fertilizer Considerations

Soil tests are done each year in a Richmond, Va. lab. Fertilizer for the annual planting beds and container plants is done biweekly, normally a 20-20-20 liquid. For the turf there are typically three applications in the fall of one pound of nitrogen per 1,000 sq. ft. and turf fertilizer is typically a 50% organic granular, for the trees, a soluble injectable fertilizer (PHZ) with mycorrhizal fungi.

Clay Swamp

When the garden was installed (opened in 1999) about three feet of clay soil was removed and replaced with a custom soil blend?EUR??,,????'??+about 77 percent sand and the rest organic matter. ?EUR??,,????'??We?EUR??,,????'???ve had to take everything out of some beds, put drainage in and replant it,?EUR??,,????'?? Cina notes. PVC pipe and soil amendments (gravel, organic matter, bark mulch) have produced good results. Some drainage culverts have also been tapped into.

Anthony Ferrell (with pitch fork) and Derrick Williams cut back ornamental grass. Ornamental grasses require relatively low levels of fertility (10-10-10), one-half to one pound of fertilizer per 100 sq. ft. of garden area. Established ornamental grass does not need regular watering except during draughts.

Tree Care

The maintenance of the garden?EUR??,,????'???s linden trees is now done in house. ?EUR??,,????'??I?EUR??,,????'???m proud of it, for sure,?EUR??,,????'?? says Kaufmann. ?EUR??,,????'??Pleaching the linden trees is something we?EUR??,,????'???re really getting into. Doing it ourselves saves us a lot of money but also gets it to our specs. I can rent a lift for a week and get it exactly how we think it should be.?EUR??,,????'?? There are two rows of lindens, 64 in all. Kaufmann does aerial hedging aboard a 60-ft. lift.

?EUR??,,????'??We head shear the tree so that the tops are boxed. It gets the effect the Gallery is looking for and reflects the intention of the landscape design.?EUR??,,????'??

Anthony Ferrell plants a winter display bed of Atlas pansies, which are suited to colder climates. Snapshot is used for the flower beds. This specialty herbicide is labeled to bring ?EUR??,,????'??up to eight months of control for 111 broadleaf and grassy weeds in 413 field-grown and 235 container-grown ornamentals without harming them.?EUR??,,????'??

Some mature elms have been susceptible to Dutch elm disease. Pruning them is limited to after the first hard frost when the beetles have been killed off by the cold weather. Soil amendments and mulching go around the trees, with care taken not to damage the bark or roots. ?EUR??,,????'??I think we treat the trees as carefully around the trees as we are with the sculptures,?EUR??,,????'?? Kaufmann asserts.

?EUR??,,????'??One root can basically cut off the circulation of the other roots,?EUR??,,????'?? he says. When the roots grow out while they are still young, he points out, the smaller fibrous roots can be pruned away.

Critter Problems

Alert! Yellow-bellied sap suckers attack the cedars in the garden, doing quite a bit of damage. Kaufmann has tired garlic sprays, putting out feeders and hanging a piece of reflective tape, which ?EUR??,,????'??failed miserably and looked ridiculous.?EUR??,,????'?? Editor?EUR??,,????'???s note: Considering the frequent bird kills around my house, I?EUR??,,????'???d release a few cats on the grounds.

Ducks also make their homes in and around the garden. The adult quackers enjoy a dip in the central fountain. Management had a ramp built to allow the ducklings to waddle into the ?EUR??,,????'??pond.?EUR??,,????'??

Irrigation

There are 32 irrigation zones for the garden and a Rain Bird system of turf and garden heads. There are three large drip zones on the perimeter to water the trees and groundcover. One furry critter, the squirrel, has taken to chewing the drip lines. There is also the problem with damaging the drip lines with weeding tools and tree roots growing over them. Kaufmann does not recommend a drip system for such highly manicured areas, though he can see the benefit for other areas.

The Professional Grounds Management Society (PGMS) awarded a prestigious ?EUR??,,????'??Green Star?EUR??,,????'?? honor award to the National Gallery of Art Sculpture Garden. This nationally recognized award is given in recognition of grounds maintained with a high degree of excellence, and salutes the grounds superintendent responsible for maintaining a well-manicured landscape year round. Pictured from left: Amanda Laudwein?EUR??,,????'??+PGMS representative, Jim Kaufmann?EUR??,,????'??+Sculpture Garden manager, and gardeners Anthony Ferrell, Michael Peters and Brian Johnson.

Equipment

Among the equipment used by the horticulture division is two Exmark 48?EUR??,,????'?? riding mowers; one New Holland tractor with backhoe and loader; eight Club Car electric utility vehicles; one 50-gal. sprayer; Stihl and Echo trimmers/edgers, chain saws, head shears, among other equipment.