14 Yellow Wildflowers in California (W/Pics!)
Did you find a YELLOW wildflower in California?
If so, I’m sure you’re wondering what type of wildflower you found! Luckily, you can use this guide to help you identify it. 🙂
Please be aware that today I’m ONLY listing and focusing on the most COMMON plants. There are so many species, varieties, and subspecies that it would be impossible to name them all. But if you want to dive deeper into all the yellow wildflowers in California, check out this field guide!
14 YELLOW wildflowers in California.
#1. Birds-foot Trefoil
- Lotus corniculatus
Also known as: Birdfoot Deervetch, Bloomfell, Cat’s Clover, Crowtoes
Growing Information:
- USDA Hardiness Zone: 3-8
- Life Cycle: Perennial
- Approximate Mature Size: 2-8 in (5-20 cm) tall
- Bloom Time: Late Spring to Early Summer
- Sun Exposure: Full Sun
The Birds-foot Trefoil has yellow, orange, and sometimes red-streaked flowers atop long stalks. As beautiful as the blooms are, this yellow wildflower is considered invasive in many areas of California. It tends to choke out native plants and overtake entire gardens and fields.
It’s especially aggressive in sandy soil, fields, parks, and roadsides. However, Birds-foot Trefoil also has its uses as long as you can control its growth. Its flowers are an important food source for many pollinators, such as bees, butterflies, and moths.
#2. St. John’s Wort
- Hypericum perforatum
Also known as: Klamath Weed, Tipton Weed, Goat Weed
Growing Information:
- USDA Hardiness Zone: 3-8
- Life Cycle: Perennial
- Approximate Mature Size: 11-35 in (28-90 cm) tall
- Bloom Time: Summer
- Sun Exposure: Full Sun to Partial Sun
St. John’s Wort has flat-top clusters of showy yellow flowers. It grows abundantly in prairies, pastures, disturbed fields, and sandy soils.
Unfortunately, this plant is an invasive species in North America. Not only does St. John’s Wort outcompete other plants, but it can also be fatal to horses, sheep, and other livestock.
Although some bees, butterflies, and beetles feed on the pollen of St. John’s Wort, you shouldn’t allow this plant to spread in landscapes. It can do more harm than good in ecosystems.
#3. Gumweed
- Grindelia squarrosa
Also known as: Rosinweed, Tarweed
Growing Information:
- USDA Hardiness Zone: 3-7
- Life Cycle: Biennial or short-lived Perennial
- Approximate Mature Size: 12-40 in (30-102 cm) tall
- Bloom Time: Spring to Fall
- Sun Exposure: Full Sun
Gumweed has aromatic, daisy-like flower clusters in shades of yellow. It grows in dry prairies, abandoned croplands, and disturbed roadsides.
It is a pollen source for native bees, but it’s mostly ignored by wildlife because of its bitter taste. Despite its showy colors, Gumweed isn’t commonly cultivated as an ornamental flower because it already grows in abundance.
#4. Yellow Marsh Marigold
- Caltha palustris
Also known as: Yellow Gowan, Cowslip, King’s Cup, Water Buttercup
Growing Information:
- USDA Hardiness Zone: 3-7
- Life Cycle: Perennial
- Approximate Mature Size: 8-24 in (20-61 cm) tall
- Bloom Time: Spring
- Sun Exposure: Full Sun to Partial Sun
Yellow Marsh Marigold is an aquatic flower that grows in marshes, ditches, wet woods, and swamps. This yellow wildflower grows best in California in cool, wet weather.
Famous for their brilliant yellow flowers that look like small goblets, Yellow Marsh Marigolds are not true marigolds; they’re actually a type of buttercup! As early bloomers, they will attract the first butterflies and hummingbirds in spring.
Yellow Marsh Marigolds are low-maintenance and disease-resistant plants. You can grow them in water gardens or along shallow bodies of water. Make sure they get plenty of sunlight to encourage more blooms.
#5. Dandelion
- Taraxacum officinale
Also known as: Common Dandelion, Lion’s Tooth, Blowball
Growing Information:
- USDA Hardiness Zone: 3-10
- Life Cycle: Perennial
- Approximate Mature Size: 6-12 in (15-30 cm) tall
- Bloom Time: Spring to Fall
- Sun Exposure: Full Sun
The bright yellow flowers that turn into balls of silver-tufted seed heads make Dandelions easy to recognize. Look for these yellow wildflowers in California in meadows, fields, river shores, lakes, and disturbed habitats. Honeybees and other beneficial insects are attracted to Dandelions.
Dandelions tend to grow like weeds on lawns and roadsides. This species is native to Europe and Asia but has spread worldwide because of how resilient it is in most soil conditions.
You can eat the leaves, roots, and flowers of the Dandelion! They taste like honey when fresh but turn bitter as the plant ages. Use them to make jam, salad, wine, or tea.
#6. Sneezeweed
- Helenium autumnale
Also known as: False Sunflower, Bitterweed
Growing Information:
- USDA Hardiness Zone: 3-8a
- Life Cycle: Perennial
- Approximate Mature Size: 24-60 in (65-152 cm) tall
- Bloom Time: Summer to Fall
- Sun Exposure: Full Sun to Partial Sun
To identify this yellow wildflower in California, look for pretty daisy-like flowers blooming in the fall. You can find Sneezeweed along streams, ponds, swamps, and wetlands. Some cultivars are popularly grown in gardens and have more showy flowers than ones in the wild.
Despite the name Sneezeweed, the pollen from this plant isn’t likely to cause allergic reactions. Its name comes from an old medicinal practice of drying and crushing its leaves to make snuff, a powder that causes sneezing. This practice was thought to remove evil spirits from the body!
Native bees, honey bees, wasps, butterflies, and beetles are attracted to the Sneezeweed. It will grow in most soil conditions and is resistant to common diseases.
#7. Black-eyed Susan
- Rudbeckia hirta
Also known as: Gloriosa Daisy
Growing Information:
- USDA Hardiness Zone: 3-9
- Life Cycle: Biennial or short-lived Perennial
- Approximate Mature Size: 24-36 in (61-91 cm) tall
- Bloom Time: Summer to Fall
- Sun Exposure: Full Sun
Look for this native yellow wildflower in California in open woods, prairies, fields, and roadsides.
Black-eyed Susans grow to graceful flowers in shades of yellow, orange, red, and brown. It owes its common name to the fact that each flower has a striking dark “eye” in the center. You can expect to see many species of bees, birds, and butterflies visiting the beautiful blooms. Goldfinches also occasionally eat the seeds.
Black-eyed Susan is a crowd favorite in gardens and parks everywhere. It will look excellent in mixed borders, wildflower gardens, and container pots. Best of all, it blooms within a year after you sow the seeds.
#8. Wild Parsnip
- Pastinaca sativa
Also known as: Common Parsnip
Growing Information:
- USDA Hardiness Zone: 4-8
- Life Cycle: Biennial or Perennial
- Approximate Mature Size: 48-59 in (122-150 cm) tall
- Bloom Time: Early Summer
- Sun Exposure: Full Sun to Partial Sun
You might be familiar with parsnip as a delicious root vegetable, but its relative that grows in the wild is dangerous to your health! Wild Parsnips smell and taste like cultivated parsnips, except their leaves and stems cause severe blisters and burns. (see below!)
To identify this yellow wildflower in California, look for its grooved stems and flat-topped flower clusters of yellow blooms.
Wild Parsnip is an invasive species in North America. It spreads rapidly, threatening to choke native plants and poisoning livestock that eats it. You can spot its vivid yellow blooms in ditches, roadsides, and abandoned fields in early spring.
#9. Wintercress
- Barbarea vulgaris
Also known as: Yellow Rocket, Herb Barbara
Growing Information:
- USDA Hardiness Zone: 5-9
- Life Cycle: Biennial or Perennial
- Approximate Mature Size: 12-24 in (30-61 cm) tall
- Bloom Time: Late Spring to Summer
- Sun Exposure: Partial Shade
Wintercress is a resilient wildflower that decorates fields with yellow blooms in spring. Its tall, upright stalks and dark green leaves will help you recognize this plant.
Native to Europe, Asia, and North Africa, this yellow wildflower is considered a weed throughout California. You’re most likely to find it in croplands, construction sites, roadsides, railroads, and waste areas.
Despite being invasive, Wintercress does support wildlife. It’s an early source of nectar and pollen for butterflies and bees in the spring. Doves and grosbeaks also like to eat the seeds.
#10. Goldenrod
- Solidago
Also known as: Flat Topped Goldenrod, Canada Goldenrod, Tall Goldenrod
Growing Information:
- USDA Hardiness Zone: 3-9
- Life Cycle: Perennial
- Approximate Mature Size: 36-60 in (91-152 cm) tall
- Bloom Time: Late Summer to Fall
- Sun Exposure: Full Sun
There are over 120 species of Goldenrod native to North America!
The blooms of Goldenrod may be tiny, but they make up for their small size with their vibrant color in the summer and fall. They grow in clusters on top of branched stems with stiff leaves.
Although Goldenrod is often blamed for hay fever, pollen grains from similar-looking plants like ragweed are likely the culprit. Enjoying the uniquely-shaped blooms is perfectly safe, but this wildflower can spread aggressively in gardens. You can contain its growth by planting it in pots and pruning it regularly.
A wide variety of specialized bees, butterflies, and beetles rely on this native yellow wildflower in California.
#11. Common Sunflower
- Helianthus annuus
Also known as: Wild Sunflower, Comb Flower, St. Bartholomew’s Star
Growing Information:
- USDA Hardiness Zone: 2-11
- Life Cycle: Annual
- Approximate Mature Size: 36-120 in (91-305 cm) tall
- Bloom Time: Summer
- Sun Exposure: Full Sun
The Common Sunflower is one of the most popular flowers all over the world, and rightfully so. The impressively large yellow petals and attractive dark centers are a classic sight in the late summer and early fall.
In the wild, look for sunflowers in prairies, grasslands, old fields, roadsides, and forest edges. But, of course, you will also find sunflowers in gardens where they’re enjoyed by people and animals alike.
Aside from their aesthetic value, Common Sunflowers also feed populations of bees, butterflies, and insect pollinators. Birds and mammals enjoy the seeds, and the best part is that you can eat them too for a tasty snack!
#12. Common Mullein
- Verbascum thapsus
Also known as: Flannel Plant, Big Taper, Velvet Dock
Growing Information:
- USDA Hardiness Zone: 3-9
- Life Cycle: Annual or Biennial
- Approximate Mature Size: 24-84 in (61-213 cm) tall
- Bloom Time: Summer
- Sun Exposure: Full Sun
Common Mullein is native to Europe, Asia, and Africa, but this yellow wildflower is now considered a naturalized species in California. It grows so well that it can take over roadsides, meadows, and pasture lands.
You can recognize this wildflower by its small yellow blooms densely grouped on a tall stem and the velvety, dense leaves at the base of the plant. As the stems shoot upwards from a base of large leaves, the overall appearance of this plant might remind you of corn.
Common Mullein is a valuable medicinal plant. In ancient times, it was used to treat pulmonary diseases, inflammations, and various ailments. Today, you can find its dried leaves, flowers, and oil extracts in health stores.
#13. Sulphur Cinquefoil
- Potentilla recta
Also known as: Round-fruited Cinquefoil, Upright Cinquefoil
Growing Information:
- USDA Hardiness Zone: 3-8
- Life Cycle: Perennial
- Approximate Mature Size: 12-20 in (30-51 cm) tall
- Bloom Time: Late Spring to Summer
- Sun Exposure: Full Sun to Partial Sun
Sulphur Cinquefoil is an invasive yellow wildflower in California.
This fast-spreading species native to Africa, Asia, and Europe can threaten native plants and ecosystems. Make sure to avoid this plant!
In the wild, Sulphur Cinquefoil grows in nearly every habitat. Look for its yellow five-petalled blooms and upright leafy stems in disturbed areas, fields, wastelands, and along lake shorelines.
Sulphur Cinquefoil has a native look-alike called Slender Cinquefoil (Potentilla gracilis). This wildflower, which can safely be planted in gardens, has short hairs on its stems and leaves, and its flowers tend to be brighter than its non-native counterpart.
#14. Spiny Sow-thistle
- Sonchus asper
Also known as: Rough Milk Thistle
Growing Information:
- USDA Hardiness Zone: 6b-9a
- Life Cycle: Annual or Biennial
- Approximate Mature Size: 11-43 in (28-110 cm) tall
- Bloom Time: Spring to Summer
- Sun Exposure: Full Sun to Partial Shade
Spiny Sow-thistle is an invasive yellow wildflower that grows throughout California. It can be found in pastures, roadsides, vacant lots, construction sites, grasslands, and waste areas. It’s native to Europe, North Africa, and Asia.
Don’t let Spiny Sow-thistle spread if you see it growing near your yard. It can overwhelm native plants and host diseases and pests that affect garden plants and crops. To identify Spiny Sow-thistle, look for spiky leaves and dandelion-like yellow flowers on tall stems.
Do you want to learn about other wildflowers in California? Check out this field guide!
Which of these yellow wildflowers have you seen before in California?
Leave a comment below!
