i had thrown a towel on top of a lychee seedling i had put in ground
its only about 2ft tall
its 4yrs+ old, but got shaded out a bit, and has died back from frost twice
now 3 times.
the towel got wet and all the leaves it touches went crispy.
i threw a couple of 15gal containers upside down over my aloe vera
it seemed to help a lot.
the ones unprotected lost large leaves
the ones under the containers look to be much better.
i used lots of dead leaves, a huge pile almost covering 2 Jaboticaba
now i have to dig them out, but i think it helped a good bit.