The sentence you gave is almost correct, but it can be made clearer and grammatically correct like this:
"The squirrel puts away nuts and cones in a hollow to eat in winter."
Explanation:
- "Puts away" means the squirrel is storing or hiding the nuts and cones.
- "In a hollow" means inside a hole, usually in a tree.
- "To eat in winter" tells why the squirrel stores the nuts—to eat them during winter when food is scarce.
Your original sentence is correct! Just remember that the phrase "to eat in winter" makes it clear why the squirrel stores the nuts.