The most common and most likely answer to this crossword clue is the 8 letter word SAPLINGS
I've seen this crossword clue in The Daily Telegraph
S
A
P
L
I
N
G
S
More clues leading to the result SAPLINGS
Buddy explains!

The straight part
We know that "little trees" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case little trees = saplings.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SAPLINGS mean?
SAPLINGS noun- A young tree, but bigger than a seedling.
- A youngster, especially a male nearing maturity.