Outdoor Light Garden

This unique, versatile outdoor light garden was built in August, 2003, and lives in our courtyard in Greenwich Village, New York City.

Constructed from cedar and pressure-treated lumber, the platform measures 6½' × 10' × 8' (200 cm × 300 cm × 250 cm) overall and contains three 400-watt high-intensity outdoor grow lights. A 4' × 8' × 5' free-standing plant stand converts for the winter to a heated cold frame, with clear 10mm polycarbonate twinwall glazing sloping from 3' high in the rear to 2' in front. The cold frame roof vents automatically and is removable.

Suitable for a courtyard, well-supported rooftop, or backyard, the platform and plant stand can be used together or separately in either sun or shade:

to grow and display plants year-round
for seed starting, hardening off, and propagation
as an arbor, outdoor dining area, or market stand

The site on which they rest should be able to support 1000 to 4000 pounds (including structures, plants, and people), depending on how they are arranged.

Japanese-inspired design

The beams of the Japanese-style platform support outdoor floodlights that serve as grow lights. A free-standing three-tiered plant stand rests inside, allowing easy access for watering. The area under the base provides ample storage.

Mortised construction

Roof and base beams are held tightly in place by carved mortises. Side beams for additional structural strength are fastened with stainless steel bolts, while the floor planks and plant stand base are held in place with stainless steel deck screws. During winter, the upper tiers of the plant stand can be removed and the base fitted with polycarbonate glazing to form a heated cold frame.

Outdoor grow lights

High-intensity grow lights are 400 watts each – two high-pressure sodium and one metal halide – manufactured by RAB. Up to six times as efficient as household incandescent bulbs, these lights provide a bright, balanced spectrum that encourages both growth and flowering. Waterproof and sturdy, designed for permanent outdoor use, they can be left up year-round.

Solid foundation

The substructure consists of a lattice of 2×4’s and 2×6’s, braced against the contours of the ground underneath and reinforced to support people, plants, and frame.

Open beamed roof

Beams supporting the grow lights are open to the sky and nestled under a nearby tree.

Insulated, heated base

The base of the stand, sheathed by cedar planks, contains a heating cable sandwiched between 3-inch layers of roundstone gravel, supported by stainless steel mesh for fast drainage. To distribute heat evenly, the 160-foot-long cable makes 21 runs back and forth along the length of the frame, guided by ½" wood dowels at each end, and is controlled by an adjustable thermostat. This, together with the thermal ballast and insulation provided by the gravel and glazing, reduces the energy required to maintain healthy temperatures during cold weather.

Removable winter glazing

Glazing (not shown) is rugged 10mm (3/8") clear Macrolux twinwall, capped to exclude moisture and insects and held in place with stainless steel hardware and water-resistant washers. The cedar frame bolts together and disassembles quickly for easy storage. The roof hinges open for access to the plants, with an automatic solar-powered vent to prevent overheating during the fall and spring, and can be removed when the weather has warmed but the danger of frost has not quite passed.