Among the joys of a California spring are swaths of annual wildflowers blooming around the state. Here in Butte County good places to view this wildflower show include Upper Bidwell Park, Table Mountain, and Feather Falls Trail.  Annual wildflowers have a life cycle that lasts just one year. Seeds germinate in the fall and winter rains (or with irrigation), roots and lower leaves grow through the winter, and plants begin to bloom in the early spring, with different species blooming into early summer. Seeds are formed and mature from late spring through summer and fall, then the mother plant dies. Seeds are spread by the mother plant, the wind, or animals, in time for the whole process to start over with the next rainy season.

Planting annual native wildflower seed can be a relatively easy and inexpensive way to add native plants to your garden. The best time to plant is from mid-October into November. Water during dry spells between rains for optimal germination. You can extend the bloom season by continuing to sow from December to March, but you will have to provide irrigation when the rainy season ends. With late sowing it is possible to have blooms well into summer. 

Natives generally prefer average well-drained soil in a sunny location, although some species will do better with afternoon shade. You don't need to add any amendments to the soil, but you need to prepare the site where you intend to sow the seeds. It's easiest to start with patches that are not too big. Clear the area of weeds without digging or tilling more than 3 to 4 inches to avoid bringing more weed seed up to the surface. You can eliminate some of the weeds by irrigating the area thoroughly and waiting for existing weed seeds to germinate. Remove those weed seedlings, and then repeat the process as much as needed.  Seeds can also be planted in raised beds, but they will require more frequent irrigation than those growing in the ground.

You can broadcast seeds by hand directly over mulch, if the mulch isn't too thick (less than 2 inches). Mulch that is thicker needs to be removed. Combine 1 part seed to 3 parts coarse sand. Scatter the seed/sand mixture evenly and cover very lightly with soil or mulch. This will help protect the seeds from birds. Tamp the area lightly. You can also broadcast bare seed over gently raked soil and cover the seeds lightly with soil. Seeds that are buried more than one-quarter inch or so may not germinate. Water after sowing with an even, soft spray.

If you have only a small number of seeds, you may want to cluster a few of them together in selected spots. Use a narrow strip of paper towel or toilet paper laid on the ground and misted with water. Spread a few seeds evenly on the paper before covering them lightly with soil and watering gently.

Weed seeds still remaining in the ground will germinate and grow along with your wildflowers and can overrun them if left unchecked. Stay vigilant with your weeding! Be sure you are able to tell the difference between weed seedlings and native wildflowers when you weed. Photos of juvenile wildflower leaves can be very helpful at this point. Some people sow a few seeds in labeled pots to use as a reference when they sprout.  Remember that seeds growing in pots will need to be watered more often than those planted in the ground.

Many people enjoy the colorful sight of a patch of mixed wildflowers. If you buy a wildflower mix, make sure it contains only seeds of wildflowers native to California, because some packages sold as “wildflower mix” will contain seeds from all over North America.  Another planting method is to sow seeds of single types of flowers in patches to form an aesthetically pleasing palette of colors. Either way, your wildflower patch will attract a variety of bird and insect pollinators. If you want the area to reseed itself the following year, don't deadhead the plants until they dry up and produce seed. You can allow the flowers to self-sow or manually collect seeds for fall planting.

Although very large patches of wildflowers are beautiful when in bloom, they're a little less appealing when the plants dry up. Large patches are also hard to keep weed-free, although it can become easier with time. Many people add some herbaceous perennials or small shrubs to the patch to provide interest when the wildflowers are spent. It's much easier to maintain smaller patches or to plant just a few seeds in small spaces in a perennial bed or in between shrubs.

Harvests & Habitats Nursery in Chico sometimes has seeds from a few native wildflowers for sale. Floral Native Nursery, also in Chico, sells a native wildflower mix, a pollinator mix, and seeds from about a dozen different kinds of native wildflowers. Online sources of native seeds include Larner Seeds, Theodore Payne Foundation, and Seedhunt.

If you're interested in seeing examples of 100 or more native wildflowers in bloom, be sure to visit the 2023 Wildflower Show, co-sponsored by the Mount Lassen Chapter of the California Native Plant Society and Friends of the Ahart Herbarium. The show will be held on Sunday, April 16 from noon to 4 p.m. at the CARD Community Center, 545 Vallombrosa, Chico.

UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at (530) 538-7201. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.