Plants that bloom in May in Zone 9 with yellow flowers

Aeonium

Dramatic rosettes on woody stems. 'Zwartkop' variety has near-black leaves. Stunning in containers.

Angel's Trumpet

Huge pendant trumpets release intense evening fragrance over a long warm-season bloom.

Calibrachoa

Mini petunias that bloom nonstop in hanging baskets. Dozens of color options and no deadheading needed.

California Poppy

Golden cups that carpet hillsides across the state. Closes at night and on cloudy days.

Chamomile

Tiny daisy flowers with apple-scented foliage. Brew into tea or let it naturalize between pavers.

Crossvine

Tubular orange-red trumpets line this vigorous semi-evergreen vine in spring, attracting every hummingbird in the neighborhood.

Daffodil

Cheerful trumpets that naturalize beautifully and return stronger each year.

Desert Marigold

Cheerful desert wildflower that blooms almost year-round in warm climates. Thrives on neglect.

Dutch Iris

Slender stems bear elegant iris blooms in late spring to early summer.

Graham Thomas Rose

Rich golden-yellow cups with an intense tea rose fragrance. David Austin's most famous creation.

Happy Returns Daylily

Lemon-yellow rebloomer with light fragrance. A bit taller than Stella with softer color.

Hawaiian Hibiscus

Large tropical blooms in vivid colors appear repeatedly from spring through fall.

Honeysuckle

Tubular, nectar-rich flowers with a fragrance that defines summer evenings.

Iris

Elegant sword-leaved perennials with intricate, ruffled blooms.

Jasmine

A vigorous twining vine with intensely sweet-scented white or yellow star-shaped flowers, the scent of warm southern evenings.

Kerria

Cheerful golden-yellow pompoms on bright green stems that stay vivid green all winter. One of the easiest shade-tolerant shrubs.

Lantana

Multi-colored flower clusters that bloom relentlessly in brutal heat.

Persian Buttercup

Ruffled, rose-like blooms in vivid colors brighten cool spring beds and pots.

Petunia

Cascading color for containers and beds. Blooms nonstop until frost.

Plumeria

Intoxicatingly fragrant tropical blooms. The flower of Hawaiian leis.

Rose

The queen of the garden. Modern varieties are surprisingly low-maintenance.

Snapdragon

Vertical flower spikes with squeeze-open blooms. Kids love them.

Stella de Oro Daylily

The most planted perennial in America. Compact, reblooming, and basically indestructible.

Western Red Columbine

Scarlet and yellow spurred flowers that hummingbirds follow through the Pacific Northwest's mountain meadows.

Wild Columbine

Nodding red-and-yellow spurred flowers that hummingbirds love on a self-sowing native that naturalizes along woodland edges.