As early as April, gardeners begin to celebrate spring at the garden center, where early-blooming annuals beckon irresistibly. Reliable, colorful and abundant, annuals bring customers back year after year for the load of flowers they provide spring through fall.
With concern for pollinators on the rise, the demand for plants that provide nourishment for bees, hummingbirds and butterflies is growing. That includes annuals, which account for more than half of all herbaceous plants purchased at garden centers in the United States, according to a survey by the U.S. Department of Agriculture. In 2023, sales of these heavy hitters totaled $2.476 billion.
Testing popular annuals
But research showing which annuals could qualify as pollinator friendly falls woefully behind studies on perennials, according to David Smitley, professor emeritus of entomology at Michigan State University. He is the lead investigator on a study to determine if any of the top six best-selling annuals can make that claim. Those half dozen — petunia, geranium (Pelargonium), pansy, begonia, impatiens and New Guinea impatiens — total more than 45 percent of the value of all annual flowers sold each year. Three to six varieties of each genus were trialed in several locations.
Turns out begonia and impatiens are visited more often by pollinators such as honeybees, bumblebees and hoverflies than any of the other plants tested, but it’s not across the board for all cultivars. Two varieties of begonia — ‘Ambassador Rose Blush’ and ‘Cocktail Brandy’ — and two impatiens — ‘Accent Coral’,’ and ‘Super Elfin XP White’ — seemed especially attractive to visitors. In fact, Smitley said the difference among varieties can be dramatic. Some varieties are five to 10-fold more popular to pollinators, Smitley said.
An earlier study by Julie Weizenhorn, Extension educator and associate professor in horticulture at the University of Minnesota, came up with six annuals that do the best job of attracting bees — including some of the 700 native bees in Oregon — as well as other pollinators like butterflies and hummingbirds. Topping the list are zinnia, sweet alyssum, marigold, lantana, pentas, portulaca and bidens. The study didn’t compare varieties or consider sales. For Smitley’s research, he chose marigold as the control plant because Weizenhorn’s research showed them to be moderately attractive to pollinators.
The research by Smitley and Weizenhorn, which surprised both of them, proves there is benefit for pollinators from annuals. However, both remained clear that perennials and woody plants, especially natives, have a lot more value for pollinators.
“We know already that most people are not going to give up their annuals, because they just love them,” Smitley said. “They’re so beautiful, and we don’t have anything as beautiful, that blooms as long as annuals, that is also really attractive to pollinators. Although our evaluation found that annual flowers were not the best choice for the purpose of attracting and supporting pollinators, I’m more interested in focusing on small improvements gardeners could make, not convincing them to abandon annuals.”
Meeting the demand
To give consumers the choices they need to make those changes, breeders will have to put pollinator attractiveness on their list of preferred characteristics right along with color, size and vigor.
“Breeders are very good at selecting flowers for their colors and how beautiful they are, but they could develop fairly easily cultivars also that are attractive to pollinators,” Smitley said. “The positive results from the study for some cultivars mean that lessons from visitation studies could help guide breeders to select pollinator-friendly cultivars of the most popular flowers.”
Hoping to nudge people to discover the interesting world of pollinator gardening is Rosie Sullivan, co-owner of N&M Herb Nursery, a retailer and grower located in Hubbard, Oregon. Sullivan, who relies on her husband’s research and peruses catalogs for pollinator-friendly annuals, hangs information signs around the nursery to educate customers about pollinators, and steers those customers to appropriate plants.
“People absolutely know about bees and butterflies and hummingbirds,” said Sullivan, who estimates 50% of her inventory is annuals. “They may not know how important pollinators are to our food system, to feeding us, but they know they love them. Once they know about plants the pollinators like and need, it brings them back every year. They tell me it brings them joy to help preserve pollinators with the plants they grow.”
Annuals are often thought of as pollinator “deserts,” meaning plants that do pollinators no good. But the research carried out by Smitley and Weizenhorn suggests that annuals do provide a food source and can help carry over the pollinators during times when perennials aren’t blooming. The research also suggests that in urban areas, annual flowers are better than no flowers at all. Choosing the right varieties can give them a role in nourishing bees and other pollinating insects in home gardens.
“For homeowners and other customers of garden centers, it means that they can choose cultivars of some of their favorite flowers that provide some support for pollinators,” Smitley said. “The key is finding them in the garden centers.”
At Peoria Gardens in Albany, Oregon, where 85,000 flats of annuals make up 40 percent of yearly sales, short cycle grower Eric Morales said the wholesale nursery is paying attention to the trending demand for pollinator plants. The public is beginning to recognize the importance of preserving pollinators. This has motivated Peoria Gardens to grow some annuals like alyssum, zinnia, salvia, bacopa and geranium, all of which they’ve noticed attract the most pollinators. With that and some research, they decide which plants to slap on a pollinator label with a bee on it.
The nursery’s commitment goes beyond pollinator plants. Concern for the environment has motivated the company to practice integrated pest management. They are currently working with the pollinator advocacy organization Xerces Society to create a pollinator hedgerow around the entire perimeter of the nursery.
Educating gardeners
“There’s a good trend starting to build up and there’s an opportunity,” Morales said. “A lot of people want a plant that flowers a long time and don’t care if it’s a pollinator plant, but more and more do. Our job is to push it forward and teach gardeners that what looks good in your front yard can also be good for pollinators. If we’re able to provide pollinator-friendly plants and teach customers about plants in the garden that attract bees and butterflies, it’s a win-win.”
Currently though, it’s difficult for consumers to figure out which varieties to buy. Smitley cautions against using random internet searches for suggestions because so much is incorrect. The best source is the Royal Horticultural Society Plants for Pollinators website, where plants are listed by bloom season. The list is heavy on perennials and shrubs but includes annuals. Priming varieties aren’t included, however.
Another strategy, he said, is for gardeners to experiment with a variety of plants in the garden, which is a good idea anyway. Diversity provides enough food for the pollinators who survive on it and gives more insects nourishment.
“They can purchase a mixture of cultivars — five or more is best — and observe which ones are visited by bees,” Smitley said. “Then they will know for future years what they look like, how well they do in the garden and how attractive they are to bees.”
One longtime gardener who pays attention is Mike Darcy, former host of both a TV and radio show and columnist for Digger. He fills about a quarter of the 100 containers in his home garden with a variety of annuals. Like most color-lovers, Darcy loves his annuals and wouldn’t give them up. But he’s observant in the garden so he can determine the best for attracting pollinators, something he believes is important.
Darcy thinks the nursery industry may be missing the boat by not growing and labelling pollinator plants. Growing and marketing pollinator-friendly plants is a good thing for nurseries, consumers and the environment.
“There’s definitely a demand that’s increasing because people are reading about it,” he said. “I see plant labels about hummingbirds but very rarely about bees.”
In his garden he’s observed some heavy visitation on basil, which he says is the No. 1 plant for attracting bees. Others that draw bees include cosmos, calendula, salvia, pineapple sage, alyssum and zinnia.
“There’s a big swath of cosmos in the neighbor’s yard and it’s constantly covered in bees,” Darcy said of some of his observations. “A good one is pineapple sage for autumn. Bees really go for them when there’s not much out there, I always have ‘Black and Blue’ salvia. They always have bees on them.”
Some nurseries recognize the pollinator trend and are doing something about it. In addition to Peoria Gardens, Proven Winners has started releasing plants marketed as pollinator friendly. Input from the Proven Winners trial team and university Extension Service programs leads the decisions on which plants make the cut to become one of the Proven Pollinators, according to Makenzie Pellissier, intellectual property manager for Proven Winners.
Salvia is high on the list. The multiple tubular flowers on tall stalks are so well suited to hummingbirds that they dive bomb anyone standing in a salvia field. Proven Winners’ Rockin’ series with varieties in fuchsia, deep purple and blue features vigorous 2- to 3-foot-tall plants that Pellissier said are “pollinator magnets for sure.”
One of the most unsung heroes for annual pollinator plants is alyssum, she said. A low mounding, trailing plant covered in fragrant small clusters of flowers in white or purple, alyssum appeals to pollinators.
“It’s super attractive to a large variety of beneficial insects,” Pellissier said. “People think of it as old-fashioned but it should be used more. It blooms spring through the cold weather and is always covered in pollinators.”
In order to succeed in their quest to create habitat for pollinators, gardeners need information like the signs Sullivan puts up at N&M or the labels developed by Peoria Gardens and Proven Winners. Homeowners can’t help pollinators, which they undoubtedly want to do, without pollinator plants and the knowledge that points them in the right direction. So garden centers should be the center of information and breeders the provider of plants.
“The bottom line is that there’s a growing demand for annual flowers that are attractive to pollinators,” Smitley said. “If people can have both beautiful color all season and plants that are attractive to pollinators, that definitely will increase the price that could be obtained and boost sales.”
From the February 2025 issue of Digger magazine | Download PDF of article
