Petunias are widely grown annual flowers, gracing gardens and containers with vibrant color throughout the summer. The question of whether these popular blooms are good for bees is common, but the answer is not simple. The relationship between petunias and bees is complex, depending on the specific flower variety and the species of bee visiting the garden. Understanding the flower’s biology reveals why many modern petunias are often overlooked by pollinators.
Why Petunias Are Not Bee Favorites
The physical structure of many hybrid petunias challenges common pollinators like honeybees and smaller native bees. Most modern varieties feature a deep, narrow, trumpet-shaped corolla (flower tube) that restricts access to the nectar at the base. This morphology prevents the short tongues of many bee species from reaching the sugary reward, causing them to move on. Additionally, petunias bred for aesthetic appeal often feature dense, double-layered blooms. These extra petals block the path to the flower’s reproductive parts, making nectar and pollen nearly impossible for a bee to gather.
Bee color perception also plays a significant role in flower preference. Bees possess photoreceptors that allow them to see ultraviolet (UV) light, and they are drawn to flowers in the blue, purple, and white range. Many commercially available petunias are bred in deep reds and magentas, colors bees perceive as less distinct or even black, making them less visible. Although some petunias contain UV nectar guides, the combination of inaccessible structure and less attractive color palettes makes many popular hybrids a low priority food source.
The Intended Pollinators of Petunias
The tubular design and specific colors of many petunias are adaptations for specialized visitors. Flowers with deep, narrow tubes and strong, sweet fragrances are suited for hawk moths, also known as sphinx moths. These moths possess a long proboscis, a straw-like feeding tube, allowing them to easily access nectar deep within the petunia’s corolla. Many hawk moths are nocturnal or crepuscular, active at dusk, which corresponds with the strong evening scent released by some petunia species.
Hummingbirds are another primary pollinator for tubular, often red or pink, petunia varieties. They are attracted to these hues, which are less visible to bees, and their long, slender bills are shaped to reach the nectar. Since hummingbirds feed while hovering, they do not require a broad landing platform, which suits the petunia’s upright, trumpet shape. For example, the rare wild species Petunia exserta, with its deep red color, evolved specifically for hummingbird pollination.
Making Your Garden Bee-Friendly
Gardeners can select specific petunia varieties that are more accommodating to bees for a pollinator garden. Varieties with single, open blooms, such as older heirloom types or certain Wave petunias, offer easier access to pollen and nectar than densely petaled double blooms. Choosing white, yellow, or pale purple petunias will increase the chance of attracting bees due to their visual preferences. These colors contrast well and are more likely to feature the visible UV guides that bees seek.
To ensure a diverse and reliable food source, petunias should be planted alongside known bee favorites using companion planting. Incorporating other plants provides a mix of floral shapes and high-nectar rewards that consistently draw bees.
Companion Plants
- Salvia
- Verbena
- Sweet alyssum
- Zinnias
Supporting general bee health requires avoiding chemical pesticides that can harm pollinators. Providing a shallow water source, like a bee bath with small landing stones, also gives insects a safe place to drink, creating a more complete habitat.