"Taller trees" is the correct way to say "更高的小树" in Engpsh.

This phrase simply describes trees that are taller than other trees. The word "taller" is an adjective that is used to describe the height of something, and it is used in this case to describe the height of trees. The word "trees" is a noun that refers to a type of plant with a woody stem, branches, and leaves.

Here are some example sentences using the phrase "taller trees":

"There are taller trees in the forest than in the park." (在森林里有比公园里更高的小树。)
"The taller trees provide more shade than the shorter ones." (更高的小树比矮的小树提供更多的阴凉。)
"The taller trees have deeper roots than the smaller ones." (更高的小树有比小的小树更深的根。)

I hope this helps! Let me know if you have any other questions.