Snazzy sunflowers for Sonoma County landscapes

Who doesn’t love a sunflower? Endlessly cheerful, radiating optimism, each flower is an encounter with happiness.

Sunflowers are one of the best annual flowers for our summer-dry climate, and now is the time to get started by shopping for seed. Native to North America, they are adapted to nutrient-poor soil, drought and heat. According to the University of Missouri Extension, they’re thought to have been domesticated about 1000 B.C. A valuable food source, sunflower seeds initially had 20 to 30% protein. Modern oil seed varieties now have more than 50% protein.

Sunflowers are in the Compositae, or daisy, family and each central disc surrounded by the ray of petals is composed of 1,000 to 2,000 clustered individual flowers that open from the periphery and move toward the center as the flower matures. With their multitude of flowers tightly configured, sunflowers make a great place to watch the many bee species that visit them. The high-protein seeds are a favorite of birds, particularly finches and titmice. Once the flowers have faded, watching the birds’ antics as they harvest the seeds and listening to their enchanting songs is one of life’s pleasures.

Most of the domesticated sunflowers we grow are selections from Helianthus annuus, a plant native to the western U.S., Canada and northern Mexico. Ranging from behemoths like Titan or Mongolian Giant, with blooms from 1 to 2 feet across, to popular selections with 6- to 7-inch flowers in artistic shades and patterns of yellow, red and burgundy, the varieties can create a compelling picture.

Wild species

Besides helianthus annuas, there are a couple of small flowered annual wild species, not as widely known, which make excellent garden subjects.

Most of them have the benefit of blooming for most of the summer rather than for about six weeks, as the Helianthus annuas selections do. Their smaller leaves and flowers make them easier to site in a garden. They are highly attractive to bees and birds. Some seed catalogs claim they will reseed in gardens, but where I’ve grown them, goldfinches have foraged so much that hardly a seed was spared.

Helianthus bolanderi Serpentine sunflower, or Bolander’s sunflower, is native to California and southern Oregon (it does not need serpentine soil). It’s only about 3 to 4 feet tall and 2 feet wide and is shrubby and densely branched from the base. Its profuse, small and bright yellow blooms have slightly reflexing petals and a distinctive central disc. The leaves are small and narrow. This sunflower does best with drip irrigation. Very easy to place and grow, including from seed, it should be more widely used. Some compost makes for more robust plants. It does well in coastal areas as well as in hot inland sites. The seeds are hard to find, but they are available from Klamath Siskiyou Native Seeds (klamathsiskiyouseeds.com) in southern Oregon, and plants are available from Annie’s Annuals and Perennials (anniesannuals.com).

The seed catalog Select Seeds has an annual sunflower they call Helianthus debilis, the cucumber leaf or beach sunflower from the Southeast and the mid-Atlantic coast. The Helianthus debilis selection offered by Select Seeds, Helianthus ‘Soluna Lemon,’ a Fleuroselect winner, is an excellent upright densely branching plant with very attractive pale-yellow 3-inch-wide flowers with chocolate-colored central discs. It grows to 4 to 5 feet tall. Despite its name, it grows well in non-sandy soil and in hot, dry climates. It blooms all summer. Please note though seed companies list it as an annual, one reviewer suspected it may be a perennial in USDA Plant Hardiness Zone 8 or above.

A favorite to try

One of my favorite small-flower sunflowers is the silver-leaf sunflower ‘Gold and Silver’ Helianthus argophyllus from the Gulf Coast and Texas.

It’s widely branched from the base with stout branches. This is a very different plant than the usual single-stalk sunflowers. The distinctive silvery-white leaves are small with a soft velvety texture that highlights the bright yellow flowers. It is about 5 to 6 feet tall and almost as wide. Give it room.

The plants are more open in form and larger than Helianthus bolanderi. Other tall annuals like orange cosmos would look great planted in between or in front of this sunflower, to disguise its sometimes-awkward growth.

It needs full sun and dryish conditions. With too much water and compost, the branches can get heavy and break. It’s also slower to flower than many other sunflowers but has a very long bloom season that the goldfinches really enjoy. The seed catalogs Southern Exposure Seed Exchange and Select Seeds have the seeds.

Kate Frey’s column appears every other week in Sonoma Home. Contact Kate at: katebfrey@gmail.com, freygardens.com, Twitter @katebfrey.