How many letters does the top answer for “hedge or fence of trees designed to lessen the force of the wind and reduce erosion” have?

The most common answer is shelterbelt (11 letters).

Crossword clue: hedge or fence of trees designed to lessen the force of the wind and reduce erosion

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

shelterbelt 11 letters wn-def

hedge or fence of trees designed to lessen the force of the wind and reduce erosion

windbreak 9 letters wn-def

hedge or fence of trees designed to lessen the force of the wind and reduce erosion