In Malaysia and Thailand, the rambutan generally fruits twice a year. The first, main crop is in June and a lesser one in December. In the Philippines, flowering occurs from late March to early May and the fruits mature from July to October or occasionally to November. Rambutan requires approximately 107 to 111 days from fruit set to harvest, with the greatest increase in fruit weight during the later stage of growth. As full ripeness approaches, the entire branch can sag under the weight and be pulled down a few feet. The green fruits (a) start to turn yellow (b) and then red (d), sometimes quite rapidly. In some years, the process from green to red can take place in 5 to 10 days.

(a)	(b)	(c)	(d)

Keep in mind that the ripe rambutan is typically red but there are some varieties that finish with a bright yellow color and some that end up with an orange blush. The flavor is pretty much the same as the red ones. The best fruit have little or no black forming on the tips of the soft spines. In 'Seechompoo', coloring occurs on rind and spinterns about 12 weeks after fruit set, total soluble solids increase from 16% at 10 days after color break to 21% at 31 days, while titratable acids fell from 0.26% to 0.16%. The harvesting time of rambutan is based on pericarp color and by counting the number of days from fruit set or from color break. Rambutan fruit has the best rind and spintern appearance and color if harvested 16 to 28 days after color break. For "Rongrien" and "Seechompoo" rambutan, the appropriate age for harvesting is 16-17 weeks after blooming or about 20 days after the change of fruit color. This is the time when the fruits attain maximum sweetness. However, fruits are frequently harvested as early as 10 days after color break to capture the higher market price. The early fruits lack the sweetness and quality of the mature fruit. The general harvesting schedule for rambutan in Thailand is between 90 to 120 days after full bloom; in Malaysia 100 to 130 days, and in Indonesia 90 to 100 days. In some varieties, it may take over 30 days between the first and the last fruit to mature, so harvesting involves several pickings. Fruits harvested 28 days after color break are considered over-mature, they usually have a darker color, lower sugar and acid content, flat flavor and are puffier to the touch. The flesh of over-ripe fruits is drier and firmer than the normal fruits, and has a more cloudy appearance. Harvesting involves cutting off the entire cluster if the majority of the fruit are ripe; if not (c), then several visits to the tree are required to complete the task. If single fruits are picked, they should be snapped off with a piece of the stem attached, so as not to rupture the rind. The fruits must be handled carefully to avoid bruising and crushing, and kept dry, cool, and well-ventilated to delay spoilage. The fruits are marketed as loose fruits or in fruit bouquets. Rambutans are highly decorative and are frequently used in floral arrangements. Rambutan bouquets are made by arranging and tying clusters of fruits together along a stalk, usually in units of a kilogram or by counts of 20, 50 and 100 fruits.

Yield: Rambutan trees bear twice annually, once in late fall and early winter with a shorter season in late spring and early summer.  The fragile nutritious fruit must ripen on the tree; they are harvested over a 4-7 week period.  The fresh fruit are easily bruised and have a limited shelf life.  An average tree may produce 5,000 to 6,000 or more fruit (60-70 kg per tree.  Yields begin at 1.2 tonnes per ha in young orchards and may reach 20 tonnes per ha) on mature trees (Tindall, 1994). It has been suggested that yields could be increased via improved orchard management, including pollination, and by planting high yielding compact cultivars. Grafted trees begin to produce at 3-4 years of age, and a mature tree can produce over 91 kg of fruit per year. In the Northern Hemisphere, flowering occurs principally between February and April, with a second flowering sometimes occurring in August and September. Fruit matures from July to October, and from November through January for the second harvest. Rambutan seedlings bear in 5-6 years, but the ratio of female to male trees is 4 or 5 to 7. One Philippine seedling orchard was found to have 67% male trees. Then, too, hardly 5% of female trees give a profitable yield.

Generally, shoots that bear fruit one year will put out new growth and will bloom and fruit the next year, so that biennial bearing is rare in the rambutan. However, yield may vary from year to year. Individual trees 8 years old or older have borne as much as 200 kg one season and only 60 kg the next. In the Philippines, the average production per tree of 21 selections was 120 kg over a 4-year period, while the general average is only 48 kg. Budded trees may fruit after 2-3 years with optimum production occurring after 8-10 years.  Trees grown from seed bear after 5-6 years.