Which is the adjective phrase in the sentence?

with xeriscape, you will save water and still grow a beautiful yard and a garden of colorful flowers in the summer.

a.
in the summer

b.
with xeriscape

c.
of colorful flowers

The adjective phrase in the sentence With xeriscape, you will save water and still grow a beautiful yard and a garden of colorful flowers in the summer, the adjective phrase is C) of colorful flowers.
A) and B) are adverb phrases.