What famous New Zealand event involves a large flower festival?

The Christchurch International Flower Festival is a renowned event in New Zealand that showcases stunning floral displays and celebrates horticulture. This festival attracts thousands of visitors, highlighting the key role flowers play in New Zealand's culture and environment. It features a variety of exhibits, floral art, and competitions, all designed to promote and appreciate the beauty of flowers along with the skills of local and international florists.

Although the other options may include smaller local events that celebrate flowers, none match the scale and notoriety of the Christchurch International Flower Festival. This festival has gained recognition as a premier floral event in New Zealand, making it justifiably the answer to the question regarding a famous flower festival in the country.