Do Longan Trees Need Cross-Pollination From Another Longan Tree?

Pollination

• The longan trees are self-incompatible where the flowers do not pollinate themselves. However, two trees are not required for pollination as pollination is done by insects, primarily bees. Bees comprise 98 to 99 percent of the insects that carry out pollination in longan trees, according to Jules Janick and Robert E. Paull in "The Encyclopedia of Fruit & Nuts." The insects visit the flowers in the early morning hours when most of the nectar secretion occurs in flowers.

Flowers

• The small flowers grow in the form of 4 to 18 inches long, wide clusters referred to as panicles. Each yellow to greenish yellow flower has 5 to 6 sepals and petals and 8 stamens. Flowers on each panicle may be functionally male or staminate, functionally female or pistillate, or bisexual or hermaphroditic. As the bees move from flower to the flower, pollination occurs. Flower panicles produce fruit clusters consisting of up to 350 or more fruit.

Fruit

• The longan fruit is referred to as drupes and is spherical to ovoid in shape with a diameter of about 3/4 inch and weight of less than 1/4 ounce. The thin, leathery outer skin is light brown to tan in color and contains a white, translucent pulp. Each fruit contains a large to small sized, shiny, dark to light brown seed. The sweet, juicy, flavorful pulp does not stick to the seed. Fruit takes 140 to 190 days from pollination time until maturation.

Flowering Period

• Longan trees produce flowers anytime between February to the start of May. The fruit is ready for harvesting in late August and September. Certain varieties of the longan also produce off-season blooms in late spring. The fruit from the off-season blooming is ready for harvesting during fall.