VTN, a Vietnamese architectural firm, is out to turn downtown Ho Chi Minh City green.

The designers are doing it by hanging window boxes on office buildings, where tenants or landlords can grow flowers, herbs, and vegetables.

The boxes, though heavy, can be moved by crane from window to window, taken down, or new ones added.

The plants have two practical functions, beyond creating a vertical urban farm growing fresh food for city dwellers, which also can provide a secondary income stream for the buildings’ owners or tenants.

First, in Vietnam’s hot climate, the plants can shade windows, helping to cool buildings naturally with less dependence on air conditioning machinery and electricity to run it.

Second, the country is urbanizing. That brings with it smog from cars, trucks, motorbikes, buses, and all the other motorized vehicles that city life depends on. Plants inhale carbon dioxide and exhale oxygen, so the window plants have a hand in reducing pollution and freshening air downtown.

TRENDPOST: This is an elegantly simple way to address several urban needs at one time. It will be replicated widely across cities not only in tropical climates but in urban centers north and south.