Too much sun for my young lychees?

[greenman62]

i know mine will put out a lot of new growth
and if the soil isnt moist, several hours of sun and heat will burn or even kill
some of that new growth.
i have a large plant in a 7gal container
and a smaller plant in ground.
They were both planted from seed at the same time
but the smaller one is shaded much of the day (it gets about 4 to 5 hours of sun)
ive not seen the smaller one in-ground loose any new leaves due to water/heat
it happens on a regular basis to the larger one (needs to be re-potted, or planted-out)
Ive noticed chemical fertilizers, even organic ones,  can add to that heat stress.

also, from what i gather, Lychee roots are particularly sensitive to heat
black containers in the direct sun are probably not a good idea..

The Longan i have really took off after i started adding a lot of leaves and mulch
 (green and brown)

[Jose Spain]

Thank you for the tips. The pots actually don't receive direct sun, I placed them there for the pics, but they are usually in a corner with tall grass that covers most of the plastic. I would prefer to plant them in the ground already, but I'm noticing that transition from summer to winter is trending to be increasingly abrupt here and planting them in autumn maybe is a bigger risk than waiting until spring.