SUNSI BAY
ST. THOMAS, U.S. VIRGIN ISLANDS
PROJECT STATUS | BUILT
PROJECT BACKGROUND
This home sits on a very exposed promontory facing Thatch Cay and other US and British Virgin Islands. Sunsi Bay can be seen in this image with a very secluded beach. This photo shows the original house before being damaged by hurricane wind and before going under complete reconstruction.
In 2012 Architect Dough White contacted us to provide landscape design services when the new home was under construction. But the collaboration did not concretize, and a local landscape contractor was hired to do a design-build installation. Ten years later, the current owner asked us to redesign certain areas that needed attention, which included a water garden that did not work to become something else, a courtyard with very unhappy plants, and a constructed wetland that was acting as sewage treatment but was no longer functional.
The owner wanted a design-build contract as they did not have qualified staff to implement the project. Our task was to develop a schematic design and then finalize the details on site. We procured all the plants from Florida, shipped them to St. Thomas, organized a holding area where the plants would be cared until installation, and instructed an unskilled crew on site step by step how to prepare soil and plant, water and maintain the investment. Soon the project expanded to building planters and steps as well, because the site had issues of accessibility and grading.
PROJECT SITE
This drone image shows the original freshwater garden pool empty, ready for drainage and soil mix under our specifications. The constructed wetland tanks are also emptied and cleaned of the dead plants and gravel, and it is still under construction.
EXISTING CONDITIONS
In the middle of the day sun would hit vertically the center of the space for a few hours, preventing to select shade-loving tropical foliage species that would otherwise enjoy the indirect sun in the rest of the day
The courtyard had no breeze as it was surrounded by building walls all around – a design not well suited for the tropics. It was in shade for most of the day and therefore had a huge mosquito's problem. Plants that would hold water (such as bromeliads) could not be used, but the owner wanted color. Four clusters of foxtail palms provided additional filtered shade, but the surviving plants under them were the ordinary macho ferns, zizi plants, asparagus, schefflera and cordyline. The base of the palm trunk is splitting, and the root initials exposed above ground. The existing soil was compacted, being ordinary clay subsoil with no organic matter and lack of drainage at a percolation test. It was completely occupied by the superficial palm roots making new replanting difficult. We suggested to amend the soil and add a 12” of soil layer on top by building a small stone curb wall all around the portico (below left and right) so we could plant without digging and disturbing the existing palms’ roots.
PLANTING DESIGN
When ready to order, many plants that we wanted to use where sold out or not available in Florida for a cold spell that decimated most of the growers’ stock. Many of the heliconia sp. and other ornamental plants selected for different seasonal flowerings were in that category.
DURING CONSTRUCTION
Amended planting soil is spread in layers after the curb walls have been built to hold it. It will be graded as a mound in the center to add additional depth so that a central grouping of Alpinia purpurata “Dwarf” can be added as a feature above the palm roots but not too tall to leave the view of the open ocean upon entry. The unattractive blue orchids plastic pots that made them die will be removed and new orchids mounted directly to the palm trunk.
The gingers, heliconia and orchids were still recovering in the holding areas, and had to make substitutions with what looked good at this time.
OCEAN SIDE PLANTERS
The planter that had previously a water garden by the pool terrace and Jacuzzi is visible here covered with a tarp and filled with bad soil that we had to eliminate. The depth was only 23,” therefore limited for engineering a drainage layer with pipes and gravel and new planting soil. About ten feet below this planter and pool terrace was a very sloppy side yard with a few scrubby plants that were not even visible from the pool (this pic is taken from the second floor of the house to show what was below) and did not add anything from the house view. When using the pool, the existing landscape was very much separated below from the monolithic pool terrace walls.
The steep side yard was difficult to use, with unstable steppingstones inserted into the slope in bare soil. We saw an opportunity here to grade the slope with three different easy to climb flight of stone stairs where the landings would become planted terraces so new vegetation would be visible from the pool terrace complementing and extending the narrow pool planter we were given to work with initially.
NEW OCEAN SIDE PLANTED TERRACES AND STEPS
Unfortunately, we were not on-site during the construction of steps and planters. The contractor did not follow our drawings and built stairs at a different grade and changed the layout. Narrow planters were built without an harmonic slight curve. Smaller landings and terraces could no longer be used to plant palms, to break the climb into a pleasing experience. We had to demolish a portion of the wall of the existing pool planter above the steps, to re-engineer more space so that the palms could be now planted above rather than in the step terraces. We had to add rock walls to expand the size of the built planters down the cliff in order to hide their walls with plants.
It was very time consuming to correct the planter walls and steps. To recover partially their function. We had to completely change the planting design, but the plants were already in holding area waiting to be planted. The three Montgomery palms had to wait for a month before the site was ready to plant them (see right). Planting had to be done before the steps and planters would be clad with stone like the rest of the house which is not ideal.
Before and after. Three Phoenix robelinii are planted to match the other existing on the other side of the house but now must share space with the Montgomery palms. Salt-resistant plants were planted along the stepped planters and recumbents will eventually hide those walls overtime. The small existing white trellis still need to be enlarged and covered by a Petrea that will provide a mass of blue flowers
The Constructed Wetland planters in the property face towards the north-east promontory across Sunsi Bay, where the only type of Evergreen Woodland plant community can be admired. The native palm groves of teyer or tyre palm (Coccothrinax alta) are probably the only naturally occurring woodlands in the USVI. Most of the other communities classified as woodlands have been caused by human impacts such as agriculture and land clearing.
Coccothrinax alta palms usually comprise about 75% of the open canopy cover of this woodland community and grow in cliffs from sea level to an altitude of about 300 meters. Mature palms range from 2 to 15 meters and can be found in various stages of growth. They are endemic to the Virgin Islands and Puerto Rico, and are able to grow both in moist and dry conditions
CONSTRUCTED WETLAND
The plant choice in this type of sewage treatment filtering and cleaning system is limited. It has been promoted in the tropics in a number of applications but requires a lot of maintenance to work long term. It was recommended in the US Virgin Island the 1980s and 1990s for residential properties close to the ocean in shallow soil conditions over bedrock, which are not ideal for septic fields.
The four planters built previously in 2012 should work as a tertiary system but there was no filtration device as a secondary system on site, and the septic tank effluent was discharging directly into the plant beds. No biodegradable or non-harming cleaning products were used in the house to guarantee the health of plants and microbes. The planted beds should have been kept with no soil and just gravel, but all the sediment accumulated over the years and the fact that the plants were probably planted directly from their pot with their soil made the system fail. Here are the beds cleaned with the drainage and gravel system restored
The plants selected for the system were taken out of their pots, washed and pruned of most of their roots and kept in hydroponic conditions (gravel and liquid solution of nutrients) for about a month before they could show new, different roots that are those that help them survive in a non-soil, periodically saturated environment. The project is still under construction
STEPS TO BELVEDERE
Below left: A long flight of steps cladded in thin coral stone tiles had been recently built into the cliff. It needed rocks adjusted on either side to prevent the steps from sticking out of the existing topography. Above right: Work for adjusting rocks to create small areas to trap soil for planting has begun. Right below: the yoga deck before planting
Planting in process in the pockets of soil created along the existing steps. The plant species used were all native, in the effort to merge with the existing plant community and lower maintenance costs. They eventually will make a mass and will cover completely the rocks necessary to hold new soil long the cliff. Some miniature decorative agave and aloe species, shown here to the right, were used among other plants around the rocky cliff of the yoga meditation deck
SUNSI BEACH
This secluded beach is hard to reach by vehicles as it is framed by steep land on either side. The Spring Bay residence, another project of ours, owns land to the north side of this bay and has access, but beaches are public in the Virgin Islands and should allow public pedestrian access. This is the beach were boats with down-islanders refugee and Haitians or Dominicans without working papers arrive in the US territory to start a new life.
