Secret Garden of 1 Utama compared with best roof gardens in the world

1 Utama has been rated the largest shopping mall in Malaysia and fourth largest in the world. How does the Secret Garden on its roof rate against roof gardens worldwide? In an attempt to find out, I searched the Internet and was initially overwhelmed by the number of roof gardens in the world. However, after imposing just four criteria, the number of gardens that qualify as ‘best roof garden’ was narrowed down to just three.

The four criteria were:

(1) The garden has to be on the roof of a building, at least one floor above ground level.

(2) The garden has to be recognizable as a landscaped ornamental garden.

(3) The planted area must be above a minimum size of 5000 sq ft.

(4) The garden has to be fully open to the public on a regular basis.

Most roof gardens do not qualify because they are private or semi-private, with restricted access.

Here is how the three roof gardens compare with each other. If I have missed any gardens that qualify, please let me know.

Kaiser Center Roof Garden, Oakland, California, USA
Designer: Theodore Osmundson
Year of Opening: 1960
Size and features: 150,000 sq ft park with fountains and ornamental ponds; lunchtime concerts on Fridays in summer.
Open on weekdays 8 am to 5 pm. Closed on weekends. Free entrance.

New Lanark Roof Garden, Lanark, Scotland
Designer: Douglas Coltart
Year of opening: 2011?
Size and features: 9,000 sq ft temperate garden with fountains, sculptures; over 70 species of ornamental plants.
Open daily, 11 am to 5 pm. Entrance by ticket.

Secret Garden of 1 Utama, Malaysia
Designers: Francis Ng & Alfred Cheong
Year of opening: 2009
Size and features: 30,000 sq ft tropical evergreen ever-flowering garden with over 500 species of trees, shrubs, herbs, climbers, epiphytes; water features, shade houses, pergolas.
Open on weekends and public holidays, 10 am to 10 pm. Closed on working weekdays. Free entrance.