The most common and most likely answer to this crossword clue is the 9 letter word FLOWERPOT
I've seen this crossword clue in The Sunday Telegraph
F
L
O
W
E
R
P
O
T
More clues leading to the result FLOWERPOT
- Where one may grow finest cannabis?
- Plant container broken? Fool! Twerp!
- Plant’s home oft cultivated to accommodate cow parsley, primarily
- Twerp, fool, horrid little weed lived by here
- Container used for river grass?
- Troop flew out to find a home for Bill – or his partner
- Fellow’s let down over drug in plant container
- Filled initially working trowel around palmetto ends?
- Where I might grow river grass?
- Vessel needing time on River Po
Buddy explains!

The straight part
We know that "Vessel" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case vessel = flowerpot.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 FLOWERPOT mean?
FLOWERPOT noun- A pot filled with soil in which plants are grown.