The most common and most likely answer to this crossword clue is the 7 letter word PETUNIA
I've seen this crossword clue in The Times
P
E
T
U
N
I
A
More clues leading to the result PETUNIA
- Tie up an awkward flower
- Flowering plant, one carried by teacher’s favourite girl
- Flower college planted in a mixture of peat
- Plant is favourite — any number I planted in middle of quad
- Potential energy I observed in fish and plant
- Peanut I fancy as a flowering plant
- Plant, peanut I gathered
- Plant I confused with peanut
- I head back to tuck into vegetable bloomer
- Something from the florist, the ultimate in tulip arrangement for auntie
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 = petunia.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 PETUNIA mean?
PETUNIA noun- Any of the flowering plants of genus Petunia, of which most garden varieties are hybrids.
- A dark purple colour, like that of some petunia flowers.
- Of a dark purple colour, like that of some petunia flowers.