The most common and most likely answer to this crossword clue is the 8 letter word HIBISCUS
I've seen this crossword clue in The Times
H
I
B
I
S
C
U
S
More clues leading to the result HIBISCUS
- It's excluded from part of elevenses in his plant
- Plant the fellow’s, having potted brown — it's missed!
- Bird nesting in the said overturned bush
- Greetings! It has left the digestives, say
- More than half of biscuit dunked in that man’s – sort of – tea
- Malaysian national symbol is in his club, left out and devastated
- Is copper lurking in Scottish club a plant?
- In setting up such a hotel chain set down plants
- Is copper being entertained by Scottish football club making a bloomer?
- Plant vaccine is about to be taken by us
Buddy explains!

The straight part
We know that "plant" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case plant = hibiscus.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 HIBISCUS mean?
HIBISCUS noun- A flower of the genus Hibiscus, especially Hibiscus syriacus, found in tropical to temperate regions, of some species used for making infusions/tea.
- A cocktail made with champagne and cranberry juice.