Tianjiyuan Research and Exhibition Greenhouse, Hunan Botanical Garden (湖南省植物园天际苑)

Hunan Botanical Garden, long known as the Hunan Forest Botanical Garden (湖南省森林植物园), lies in Yuhua District, Changsha. Its new research and exhibition greenhouse, named Tianjiyuan (天际苑), represents an investment of more than 40 million yuan.

Completed at the end of December 2024, it first opened on a trial basis; local reports date this to 26 or 27 December depending on the article. After nearly three months of trial running, the official opening took place on 22 March 2025, together with an immersive rhododendron show that ran until the end of May.

The building closed again from 2 to 9 September 2025 and reopened on 10 September with a refreshed presentation; the report announcing it does not say what was changed. The sources consulted name neither the architect nor the builder, and give no date for the start of construction.

The greenhouse covers 6,313 m² in all and is divided into four halls of different sizes: 990 m² for the tropical rainforest, 1,664 m² for famous flowers of the world, 1,504 m² for desert plants and 1,312 m² for subalpine flora.

Each hall recreates the native setting of its plants. In the rainforest, a walkway runs at canopy level and brings visitors close to aerial roots and to plants strangling their hosts. The subalpine hall, whose layout draws on Hunan's four great mountain systems, houses species from 800 to 3,000 m above sea level: the temperature is kept below 28 °C in summer, while in winter it follows the outdoor climate.

Capacity is set at 2,000 visitors a day and 300 people at any one time. The reports consulted describe neither the height nor the materials of the structure.

More than 2,500 species and cultivars are conserved across the four halls. The rainforest hall has over 600, the famous-flowers hall over 500 and the desert hall more than 520. The subalpine hall, the richest with over 750 species, is described as the only venue to bring together Hunan's wild subalpine tree species.

The plants highlighted in press coverage include tree ferns (桫椤), bottle trees, baobabs, cacti, jacaranda, carnivorous plants, tropical water lilies, begonias, the foxtail palm and the traveller's palm.

In spring 2025 the famous-flowers and subalpine halls hosted more than 1,000 rhododendrons in 37 varieties.

The greenhouse stands in the northern part of the botanical garden, beside its research buildings; a March 2025 report places it near the north gate and the Famous Flowers Plaza. Allow an hour to an hour and a half for the four halls.

Spring, the season chosen for the 2025 rhododendron show, is the liveliest time. Because daily numbers are capped, holiday weekends are best avoided. OpenStreetMap shows the rose garden (月季玫瑰园) and Cherry Blossom Lake (樱花湖) a few hundred metres away, making for an easy extension of the walk.