March 30, 2019
Did you know you can identify the species of a hummingbird by the hum it makes when flying? Their wings vibrate on upstrokes and downstrokes, which produce a distinct hum according to the frequency of their wing movements.
Often called colibri (or kolibri) in many languages, my favorite name for them is the Portuguese name, beija-flor, which translates to flower kisser. Planting hummingbird-attractive flowers in your Marin garden is the best way to invite these flying jewels to visit.
Hummingbirds in flight have the highest metabolism of all vertebrates. A hummingbird consumes about half its weight in sugar every day. The rest of the hummingbird’s diet is made up of small insects which provide their protein and minerals. A hummingbird will consume hundreds of insects a day. If you want to see hummingbirds in your garden, make sure you don’t use pesticides and plant hummingbird-pollinated flowers so there is plenty of nectar year-round.
Hummingbird-pollinated flowers tend to have long central narrow tubes that force the bird to stick its long beak inside, which then causes its head or body to brush against the flower’s reproductive organs. Pollen from the anthers sticks to the bird and is deposited on the stigma when it licks nectar. Hummingbird-pollinated flowers usually have significantly more pollen than insect-pollinated flowers, which makes sense since they are visited less frequently.
Hummingbirds use both vision and taste when searching for nectar since they have no sense of smell. Flowers visited by hummingbirds have mild odors or no scent at all. Strongly perfumed flowers are designed to attract insect pollinators.
Hummingbirds prefer flowers that have bright colors, particularly red, yellow and orange. The hummingbirds’ sense of color is due to the dense concentration of cones in its retina. These cones contain pigments and oil droplets in shades of yellow to red, which seem to act like filters. The filters appear to heighten color sensitivity in the red to yellow range, while muting colors such as blue.
The most important characteristic of hummingbird-pollinated flowers is that they are nectar rich with the preferred nectar concentration. Hummingbirds will drink from flowers with sucrose concentrations of 7 to 60 percent, but their ideal is about 24 percent sugar. (A soft drink is about half that.) When people fill feeders, they use ¼ cup granulated sugar well mixed with 1 cup of water, which is close to the ideal 24 percent.
Long bills and grooved tongues are specialized for nectar collecting since the long beaks help hummingbirds get into the tubular flowers. However, the tongue does all the work with 18 licks per second.
There are a lot of lists on the internet of flowers that attract hummingbirds, but I will share with you the ones I have seen frequently visiting my home garden and in Harvey’s Garden, the UC Marin Master Gardener demonstration garden in Tiburon.
In the winter, manzanita, rosemary and aloe blooms provide a steady source of nectar. Ribes are another good source of nectar in the winter, as are winter- blooming grevilleas. In the shade, try hummingbird sage, which will bloom from winter through the summer.
Hummingbirds love sages, particularly the salvia bumble, which can be found at both gardens. Also popular is the salvia Clevelandii, lion’s tail, lobelias, lilies, lavender and larkspur, which are all loved by hummingbirds. Perennials such as Peruvian lilies, foxglove, red hot poker, penstemon and monkeyflower also attract hummingbirds. They love the bottlebrush at Harvey’s Garden and I see them visiting my citrus trees daily.
An important nectar source for the fall is California fuchsia, which is about the easiest plant there is to grow, and it doesn’t really need water once established. California columbines are well visited and will do well in part sun.
For information about our Marin demonstration gardens, please go to marinmg.ucanr.edu.