2.Quezon City Circle
Mindoro is one of the top producers of calamansi for the Philippines.
This place is near LRT Gil Puyat / Buendia station.
Near the pet stalls, you'll find the area for plants and garden needs. Pots of different sides, cactuses, flowering plants like mums, marigold and orchids, culinary herbs like basil, mint, parsley, are available here depending on the season. You can find calamansi seedling for sale in here also.
This is a good site for buying bulk orders of calamansi plants.
I heard that the soils coming from Talisay are good for the plants because it is enriched when there was Taal volcano eruption many years ago.
7.Manila Seedling Bank http://msbfi.com/