Sea grapes grow in tropical and subtropical coastal waters, especially in shallow, warm sea areas with sandy or muddy bottoms. The three most important cultivation areas are Okinawa Prefecture in Japan, the Visayas region in the Philippines and coastal regions in Vietnam. There they thrive in lagoons or calm coastal areas with little current, often in aquaculture systems.

The plants are light to medium green and are characterised by grape-shaped bubbles (thallus ends) that resemble small green pearls. The shoots are usually 10–20 cm long. The algae grow creeping across the sea floor, with sideways-pointing ‘tendrils’ that are branched like grapes.

Umibudo is mainly cultivated, not harvested in the wild. Harvesting is done manually by separating the mature shoots from the main strands. Family businesses and cooperatives organise the harvest and further processing. After harvesting, the algae are thoroughly rinsed with sea water and placed in salt to extend their shelf life. They are then packaged in airtight containers for transport and storage at room temperature or in a cool place.