The most common and most likely answer to this crossword clue is the 8 letter word ARBORETA
I've seen this crossword clue in Financial Times
A
R
B
O
R
E
T
A
More clues leading to the result ARBORETA
- Gardens conveyed in painting first class
- Special gardens suffered in a motoring accident
- Groups of elders, maybe?
- Wooded Gardens from retro artist sporting boater
- A right uninteresting person leading volunteers in the woods
- Lots of trees well planted in craft area
- Rare boat fashioned in various woods specially cultivated
- Not in aberration uprooting trees
- Gardens conveyed in painting — Appian's first
Buddy explains!

The straight part
We know that "Groups of elders, maybe" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case groups of elders, maybe = arboreta.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 ARBORETA mean?
ARBORETA noun- A place where many varieties of tree are grown for research, educational, and ornamental purposes.