How do I solve 18 across in Daily Telegraph Cryptic 31246?

Question

Accepted Answer

18 across reads "Growing high and mighty, called out the arts" (12 letters); the answer is HORTICULTURE. It's a homophone clue: the answer sounds like another word. Indicators like 'reportedly', 'we hear', or 'sounds like' point to a word that's pronounced similarly to the answer. The full step-by-step breakdown is on this page.

Growing high and mighty, called out the arts (12)

18A — Growing high and mighty, called out the arts (12) — HORTICULTURE