Q.information about lychee tree
i have lychee tree for 5 years. no fruits yet. last summer all leaves turned brown and shed. got new leaves. will like to know how to take care of my lychee tree. when to fertilize and when will i see fruits. flowers come but no fruit
All leaves turning brown and shedding in the summer indicates possible severe water deficit/drought stress. You may not have watered adequately during the hot dry season, which was extreme in your location this past summer.
Physiological stress like this can affect fruit development.
Good soil fertility and water management is vital for growth, flowering and fruiting.
Fertilize spring and fall with a complete organic fertilizer like this:
https://www.domyown.com/dr-earth-organic-all-purpose-fertilizer-p-9485.html
Deep water once a week. Try to achieve a water infiltration depth of 6 - 10 inches. (drip emitters or light sprinkling of the soil surface is not enough. Mulch the soil surface with at least 2" of organic matter to help retain soil moisture.
Here's an article with some more tips.
https://www.gardeningknowhow.com/ornamental/trees/lychee-tree/growing-lychee-trees.htm