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.

Bartzella Peony

Intersectional Itoh hybrid with huge lemon-yellow double blooms and red flares at the center. Strong stems hold up to 50 flowers per plant.

Butter and Sugar Siberian Iris

Cream-white standards over butter-yellow falls. The first dependable yellow-and-white Siberian iris ever introduced.

Calendula

Bright daisy-like blooms in pumpkin orange and gold. Edible petals brighten salads and the plant keeps blooming through cool weather.

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.

Ixia

Wiry stems hold star-shaped flowers in jewel colors. Corn lily, a long-lasting cut flower that closes at night and opens with the sun.

Jasmine

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

Julia Child Rose

Butter-yellow ruffled blooms with a sweet licorice-candy fragrance. The chef's own pick for her garden and one of the best yellow floribundas ever bred.

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.

Lemon Chiffon Peony

Intersectional Itoh hybrid with pale lemon-yellow semi-double blooms. Bartzella's softer-toned sibling with the same strong stems and long bloom.

Peace Rose

Massive cream-yellow blooms with rose-pink edges. The most famous rose of the 20th century, released the day Berlin fell in 1945.

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.

Portulaca

Succulent-leaved sun lover with silky rose-like blooms that thrives where pavement, rock, or sand defeats everything else.

Pride of Barbados

Flame-orange and yellow flower clusters that hummingbirds and swallowtails cannot resist. Thrives on heat, dies back at frost, returns every spring.

Rainbow Knock Out Rose

Coral-pink single blooms with a yellow eye on the same indestructible Knock Out frame. Self-cleaning and disease-resistant like the original.

Roald Dahl Rose

Peach-apricot cups in soft warm tones with a tea rose fragrance. Tireless rebloomer with excellent disease resistance.

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.

Sunny Knock Out Rose

Bright lemon-yellow single blooms that fade to creamy white. The only Knock Out with real fragrance, and just as bulletproof as the rest.

Sunsprite Rose

Brilliant deep yellow floribunda blooms that hold their color even in hot sun. Sweet fragrance and outstanding disease resistance.

Wallflower

Velvety blooms in burnished sunset tones with a sweet violet fragrance. The forgotten cottage staple worth bringing back.

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.

Yellow Bells

Clusters of bright yellow trumpet flowers bloom for months in the heat. Southwest staple that takes drought and reflected heat without flinching.