What is in season now in Hong Kong?

 

As per the HK Government's Agriculture, Fisheries and Conservation Department website:

All year round crops include lettuce, flowering Chinese cabbage, Chinese white cabbage and Chinese kale.
Winter spring crops include watercress, spinach, matrimony vine and chayote

Summer crops include water spinach, Chinese spinach, yard long beans, hairy gourd and bitter cucumber. See picture opposite.

Mango Menus' Guide to Seasonal Produce

Bitter cucumber in season in summer