|I have two large Lychee trees that are around 5-8 years old. Only had a little fruit on one tree several years ago. What can I do to make them fruit? They are planted in my backyard in the sun, and look healthy.|
|I don't know whether the problem is with lack of pollination or with the climate. You didn't mention whether or not your trees are flowering. I presume they are. Lychee flowers are pollinated by bees and various fly species. Isolated or single lychee trees will usually set acceptable amounts of fruit. However, recent research has demonstrated that under some conditions, cross-pollination among different cultivars may increase fruit set. Therefore, in some cases there may be an advantage to planting more than one variety.
Lychee does not fruit satisfactorily at sea level in tropical climates. It is better adapted to warm to cool subtropical areas. The best climates for lychee production have a dry, cold (but nonfreezing) winter period lasting 3 to 5 months; a warm spring during the flowering period; a hot and humid summer during fruit growth, development, and maturation; and moderately warm temperatures during the fall. Periodic rainfall during spring and summer is ideal.
Since your trees set fruit in the past, I'll wager that the winter and spring weather was just right that year and that you'll need to be patient and hope the winter and spring weather will cooperate for fruit production next year.