DUBLIN, May 30 (Xinhua) -- Bloom Festival, Ireland's largest garden festival, was officially opened to the public by Irish President Michael D. Higgins in Dublin's Phoenix Park on Thursday morning, attracting tens of thousands of visitors both from home and abroad.

Organized by Bord Bia (Irish Food Board), a state agency for promoting sales of Irish food and horticulture, the festival not only entertained visitors with beautifully designed gardens, but also offered them free lectures on how to cultivate and manage a garden.

A total of 36 gardens, all designed by locals, were displayed at the festival. They included 22 show gardens and 14 postcard gardens which refer to those smaller in size and less professional in design than show gardens.

An Argentinian-themed show garden designed by a Dublin-based garden designer named Alan Rudden won the top prize of the festival based on the recommendations of seven independent expert judges.

The team of the judges also selected a garden which involved the work of a Chinese student from Trinity College Dublin as one of the five Silver Gilt Medal winners.

Named E3 Garden, the creation featured a technology as how to transform wastewater into clean water for reuse in gardens. The three Es stand for Environment, Engineering and Emerging technologies, said Li Dunzhu, who is currently studying his doctorate in environmental engineering at Trinity College Dublin.

The E3 Garden, which was jointly created by Li, his tutor and an Irish designer, won the prize for a solution it provides to water shortages due to climate change, said the judges.

Sustainability, biodiversity and environment are the themes of the festival for this year with gardeners focusing on less manicured gardens.

Apart from the gardens, the festival also displayed hundreds of varieties of plants and flowers in greenhouses temporarily set up at the festival venue.

A food village aimed to promote the quality Irish food products and drinks was also set up inside the festival venue.

Over 100 local food and drink exhibitors participated in the festival, said organizers, adding that live music and fashion shows are also provided at the event.

The five-day festival, which is in its 13th year, is expected to draw an estimated 120,000 visitors, said organizers.