The most common and most likely answer to this crossword clue is the 8 letter word GARDENIA
I've seen this crossword clue in Financial Times
G
A
R
D
E
N
I
A
More clues leading to the result GARDENIA
- Drainage sorted for shrub
- Dig near a wild flower
- Shrub in grand forest on borders of India
- Plant needs a place to grow it, I answer
- Plant in Grade A condition
- Flowery plot – one with a shrub
- Drainage construction plant
- Flower in appropriate place, excellent for mounting
- Shrub requiring exceptional drainage
- Drainage sorted out for plant
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 = gardenia.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 GARDENIA mean?
GARDENIA noun- Any of various tropical evergreen small trees or shrubs, of the genus Gardenia, having glossy leaves and white flowers.
- The flower of these plants.