A guide to goldenrods: How to brighten your space with this easy, late-summer plant

August is waning and late summer bloomers like goldenrods are putting on a brilliant yellow show. Plants that bloom in summer and fall are valuable in a couple of ways. Their foliage usually looks great all summer and needs no maintenance beyond removing a stray stem here and there. One-time maintenance occurs in the fall or winter after bloom is finished.

Goldenrods flowers are aglow when many other plants are winding down after the long growing season. There are many species of native goldenrods - each growing in different areas of the nation. They have deep green, lance-shaped fairly coarse leaves, and usually large sprays (terminal pyramidal panicles)of tiny clustered flowers that create a showy scene. Goldenrod has had an unearned reputation for causing allergies from wind-blown pollen. In reality, it’s pollen is sticky, and must adhere to a bee to be transported. It does not blow in the wind.

Goldenrods are important plants for bees - both honeybees and native bees. In general, our gardens decline in the fall and there is less in bloom at a crucial time of year when honeybees need to store nectar to support the colony through the winter. Goldenrods small flowers are clustered together in sprays along stems, and each stem holds several hundred of them. These many small flowers serve as prolific resources of late season nectar.

The plants are strong producers of nectar with sugar concentrations as much as 33 percent. Native bees gather the pollen to provision nests for their young.

Species that are active late in the season depend on plants like goldenrod for this. Goldenrod is also very attractive to many beneficial insects and butterflies.

Goldenrods are very easy to grow. They are perennials that spread by creeping roots (rhizomes) over time- some aggressively - so take care where they are planted. The lower varieties can form a groundcover over time. Moist and fertile soil will speed up their spread. Goldenrods can be kept in check each year by digging out any unwanted growth with a shovel. They can be included in a mixed flower border, but need to be monitored to keep them in check.

Goldenrods are best grown in full sun or some partial shade. In winter they should be cut down to about 1-2 inches. They form a dense, low groundcover in winter, and sprout stems in spring. Most are drought and deer resistant in our area.

Goldenrods are excellent meadow plants and are often found growing naturally in them. They can also be included in native hedgerow plantings to grow as a lower story between shrubs. If you have a large garden, plant some in a neglected corner with minimal irrigation and let them go.

Our native goldenrod is called California goldenrod (Solidago velutina californica). It is about 2-3 feet tall and has showy deep yellow flowers at the end of tall stems. The leaves are narrow and pointed. The plant does have a wild look and is probably best for naturalistic situations. It is drought tolerant, but blooms longer with some water. A more garden-worthy selection is called Solidago californica ‘Cascade Creek’. It has much larger and more showy blooms, flowers for a longer period and has a dense growth habit. It is not supposed to spread as aggressively. The UC Davis Arboretum grows this variety and lists it on their All-Star Plant List. A similar goldenrod to ‘Cascade Creek’ is a hybrid called ‘Tara’. It grows from 2-3 feet tall and has huge showy bright yellow blooms.

Solidago rugosa ‘Fireworks’ or rough goldenrod is commonly available in nurseries. It is between 2 and 3 feet tall and has handsome very deep green, rough or rugose foliage. The stems are stiff and the whole plant is compact and upright. It is not one of those perennials that flop over. The flower sprays are large, showy and resemble a spray of fireworks. They arch horizontally and have a definite structure to them. This variety makes good cut flowers.

A smaller, more easily managed goldenrod with a beautiful more pale yellow bloom, is called Solidago ‘Little Lemon’. It is a hybrid.

Solidago ‘Little Lemon’ grows to 1-foot tall and blooms midsummer to fall. Its color combines well with other colors like those of the hummingbird mints or agastaches. The blooms are held on horizontal stems like the Solidago ‘Fireworks’ It is not as strong a plant as other goldenrods and spreads very slowly, and requires more regular water.

Another smaller goldenrod - from 1-2 feet tall - is a hybrid called Solidago ‘Golden Baby’. It has lance-shaped leaves and huge, bright yellow sprays of flowers.

Birds like to eat the flower seeds as they mature.

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