Cold Greenhouses, Shanghai Botanical Garden North Zone (Subalpine and Mountain Plant Pavilions)

Shanghai Botanical Garden, in Xuhui District, covers 81.86 hectares. Founded in 1974, it was known from the start for its camellias, rhododendrons and orchids. Its North Zone, beyond the Zhangjiatang channel, was the object of a large extension and redevelopment project launched in August 2020: on nearly 22 hectares, themed gardens were created, among them two greenhouses of a new kind for the city.

The designers wanted "cold" greenhouses, meaning cool ones, for plants that cope badly with Shanghai summers. Three families were chosen: gesneriads, heaths (rhododendrons) and the tea family (camellias). The garden has long collected and studied them, and few Chinese greenhouses display them; the choice was also meant to set the garden apart from the country's other exhibition greenhouses.

On 28 September 2023, when the North Zone partly opened, both buildings were still under construction, and the press announced that they would open the following year. They received their first visitors in April 2024, as the Shanghai flower show opened on 18 April: a report dated 19 April 2024 describes them as open to visitors and the North Zone as fully accessible. Online encyclopaedia entries differ slightly on the exact day (19 April or May 2024). In 2026, two members of the garden's staff published a detailed description of the project in the World Journal of Forestry.

The two pavilions stand on the north shore of the North Zone's scenic lake, in a clean contemporary style. Their half-round bodies are reflected in the water and form a complete circle, an image the press compares to an eye, butterfly wings or a snail shell.

The Subalpine Plant Pavilion covers 1,004 m², rises 19.65 m and spans up to 40.9 m; the Mountain Plant Pavilion covers 481 m², reaches 13.95 m and spans 32 m. The structure is a single-layer lattice of rectangular steel tubes and aluminium alloy under an arched roof that reduces wind load and snow load. Large glass curtain walls and skylights bring in light and ventilation; according to the press, a canopy cloth stretched above the glass tempers the sunlight.

The climate is managed by air-cooled screw units installed outdoors, which supply cooling in summer and heating in winter; the air-handling plant, housed underground, also humidifies. The Subalpine Pavilion aims at 26 to 30 °C in summer and is not heated in winter; the Mountain Pavilion at 22 to 33 °C in summer and at least 13 °C in winter. Roof fans, free-draining soils and purified water for acid-loving plants complete the equipment.

The Subalpine Plant Pavilion reconstructs plant communities between 1,000 and 3,000 m in altitude. Its main display brings together 66 taxa of Ericaceae, hybrids and species alike, among them the giant tree rhododendron Rhododendron protistum var. giganteum, rated critically endangered by the IUCN, and 118 taxa of camellias arranged by origin (Yunnan, Sichuan, eastern China, yellow camellias, seasonal bloomers), including 32 traditional cultivars of Camellia reticulata; the camellias flower from November to early May. Three landscape tanks evoke a woodland wetland, high-altitude rocks and a carnivorous-plant habitat that includes Nepenthes veitchii and Nepenthes spectabilis.

The Mountain Plant Pavilion is devoted to gesneriads, a family the garden has collected for years (over 400 taxa). It shows more than 200 according to the garden's own text, 143 in the breakdown by zone, divided between an Asian section, on limestone cliffs and rock gardens, and an American and African section. A "cave" section presents cave-dwelling species such as Primulina huangii. Begonias, ferns, mosses and orchids accompany them.

Both pavilions occupy the North Zone of the garden, along the lake and north of the Zhangjiatang channel. Gate 4, on Luocheng Road, is the closest: from Shilong Road station (Metro Line 3), cross a footbridge and follow Dongquan Road. Entry to the garden has been free since 2022, but the greenhouses are ticketed; an April 2024 report said a ticket for the large South Zone greenhouse also gave access to the cold greenhouses on the same day, which is worth checking before a visit.

Allow an hour for the two pavilions, more with the North Zone's other gardens (irises, a Mediterranean garden, ornamental grasses, a rock garden, mosses). Camellias are best seen from winter to early spring; temporary shows change the displays. The pyramid-shaped greenhouse in the South Zone, opened in 2001, rounds off the visit.