The lilac, with its dense clusters of fragrant flowers, is a beloved sign of spring in many temperate gardens. Gardeners often plant these shrubs hoping their abundant blooms will attract pollinators, including hummingbirds. Understanding the specific feeding biology of hummingbirds, however, reveals that not all beautiful flowers are equally attractive to them.
Lilacs and Hummingbirds: A Mismatch of Anatomy
Hummingbirds may occasionally investigate a lilac bush, but the shrub is not a reliable food source for them. The floral structure of the common lilac (Syringa vulgaris) is the primary factor in this weak relationship. Lilac flowers have a short, open corolla tube that does not require the specialized feeding apparatus of a hummingbird to access the nectar.
This open flower shape is optimized for generalist insects, such as bees and butterflies, which can easily land on the small petals. Lilacs also produce very little nectar compared to the high-yield flowers hummingbirds seek out. These birds have an extremely high metabolism, requiring them to feed frequently on concentrated sugar solutions.
The low quantity of nectar means the energetic cost of visiting lilac blooms often outweighs the nutritional reward. A hummingbird needs to visit thousands of flowers daily to meet its energy demands, making feeding efficiency paramount. Therefore, the lilac does not provide the consistent, high-volume fuel source required by these specialized aerial feeders.
Visual and Structural Cues That Attract Hummingbirds
Successful hummingbird flowers have evolved specific features that advertise their rich energy content while deterring other pollinators. Hummingbirds show a strong preference for flowers colored in shades of red, orange, and deep pink. This color range is highly visible to the birds and often signals a flower that lacks the ultraviolet patterns visible to bees, reducing competition for nectar.
Structurally, the ideal flower possesses a long, narrow, tubular corolla that perfectly accommodates the bird’s elongated bill. This tube shape ensures the bird’s head contacts the anthers and stigma, facilitating pollen transfer. The deep placement of the nectar acts as a selective barrier, ensuring the plant receives dedicated pollination services while making the nectar inaccessible to insects with shorter mouthparts.
The nectar itself must be composed of a high concentration of sucrose to efficiently power the bird’s rapid wingbeats. Hummingbirds prefer flowers that offer a reliable supply of this concentrated sugar solution. This combination of specific color, shape, and nutrient content is the result of co-evolution, creating specialized floral resources.
Optimizing Your Garden With Ideal Nectar Sources
To successfully attract and sustain hummingbirds, focus on planting species that possess the deep, tubular structure and high nectar yield they require. Vining plants provide vertical feeding opportunities, which hummingbirds often favor.
Recommended Plants
Excellent choices include:
- Bee Balm (Monarda) and Salvia (sage) are highly regarded for their long bloom times and robust nectar production.
- Trumpet Honeysuckle (Lonicera sempervirens) offers bright red tubular flowers that act as powerful visual beacons.
- Trumpet Vine (Campsis radicans) provides climbing opportunities with its orange tubular flowers.
- Fuchsia is an excellent choice for containers or warmer climates.
- Agastache (Hummingbird Mint) provides continuous, nectar-filled blossoms.
Beyond specific plants, creating an inviting habitat involves providing perching spots and minimizing chemical use. Leave slender branches or wires near feeding areas, as hummingbirds frequently pause to survey their territory and conserve energy. Avoiding pesticides is important, as hummingbirds supplement their diet with small insects and spiders, a necessary source of protein. Grouping similar high-nectar plants together creates a mass of color that signals a reliable food source and encourages repeat visits.