The most common and most likely answer to this crossword clue is the 4 letter word FERN
F
E
R
N
More clues leading to the result FERN
- Plant in bogland across river
- Plant originally raised in marshy land
- Bog giving a home to river plant
- Marshy area includes river plant
- River in Slough bearing bracken?
- Some prefer northern plant
- Plant by river in marshland
- Marshy land providing habitat for rare plant
- Non-flowering plant westwards somewhat unrefined
- Plant that’s right in marshy ground
Buddy explains!

The straight part
We know that "shoot" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shoot = fern.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 FERN mean?
FERN noun- Any of a group of some twenty thousand species of vascular plants classified in the division Pteridophyta that lack seeds and reproduce by shedding spores to initiate an alternation of generations.