HONG KONG (AFP) - It's notorious for its cramped living conditions, traffic-clogged streets and polluted air, but once a year Hong Kong celebrates all things green at the city's flower show.

Though most residents have no outdoor space for gardening, thousands flock to the annual 10-day event, which started on Friday and covers six football pitches in the central Victoria Park.

In contrast to the surrounding apartment and office blocks, the park has been overtaken by cascades of orchids - the show's theme flower - along with tulips and kitsch floral sculptures, from giant ants to pandas and toadstools.

Some visitors come just to photograph the lavish displays, but many are picking up plants and gardening equipment. The park is lined with stalls selling seeds, pot plants, compost and garden tools.

It's a testament to the fact that, despite Hong Kong's cheek-by-jowl and high-rise lifestyle, its residents crave greenery and are making the most of the limited space they have to grow plants.

Queenie Wong, 25, who is studying Chinese medicine at Hong Kong Baptist University, holds a tiny fern in a pot, which she has just bought from one of the stalls.

"I don't grow anything at home because I don't have the space. I'll take care of this plant in my university office, which is where I spend most of my time," she says.

Like many in Hong Kong, 11-year-old Zoe Shum makes do with a balcony at home for her horticultural ambitions.

"I grow bamboos on a balcony, but I wish I had more garden space to grow more things. At school we have lots of plants and they're really pretty," she said.

For 30-year-old Amy Tang, the show is a chance for her parents to stock up.

"I bring my parents here every year because they like to shop for plants for their balcony - and we like just looking at the flowers," she said.

Hong Kong's popular image is of a frenetic commercial hub where making a fast buck trumps all other concerns, but flower show chairman Horace Cheung says its seven million people do enjoy connecting with nature.