Buzz & Bloom: Sunflowers & Leafcutter Bees

There are few flowers that announce themselves in the garden quite like a sunflower. Tall, bright, and easy to grow, sunflowers are a favorite for gardeners—and they’re also a valuable food source for pollinators.

For this month’s Buzz & Bloom, we’re pairing the sunflower with a fascinating but often overlooked pollinator: the leafcutter bee. These solitary bees may be small, but they play an important role in pollinating gardens and food crops.

Meet the Sunflower

Sunflowers (Helianthus spp.) are much more than one giant flower. What looks like a single bloom is actually a collection of hundreds of tiny flowers called florets.

The tiny flowers around the outside are called ray florets and give the sunflower its familiar petals. The center is made up of hundreds of disc florets, each capable of producing pollen and nectar. This unusual structure makes sunflowers a busy stop for pollinators.

Depending on the variety, sunflowers can attract bees, butterflies, beetles, and other beneficial insects. After pollination, the flowers develop seeds that can be harvested for people—or left in the garden as food for birds.

A sunflower is a garden multitasker:

• Provides nectar and pollen for pollinators
• Attracts a variety of native bees
• Produces seeds that feed birds
• Grows quickly from seed
• Gives gardeners an easy way to observe pollination
• Provides teachers with a great living science lesson

Meet the Leafcutter Bee

When most people think about bees, they picture honey bees living together in a hive. Leafcutter bees are very different.

Leafcutter bees are solitary bees, meaning they don’t live in large colonies or produce honey. Each female bee creates her own nest and gathers pollen and nectar to provision her young.

And then there’s the behavior that gives these bees their name.

Have you ever noticed small, perfectly rounded pieces missing from the edges of leaves? A leafcutter bee may be responsible!

Female leafcutter bees cut small pieces from leaves and use them to construct individual chambers inside their nests. The leaf pieces are carefully arranged to create a safe place for their developing young.

The cuts may look like something is eating your plant—but there’s usually no reason to treat the plant. Leafcutter bees generally cause little damage to healthy plants, and their work is a sign that native pollinators are using your garden.

Why Sunflowers and Leafcutter Bees Make a Great Pair

Sunflowers provide an abundant source of pollen and nectar, while leafcutter bees can contribute to pollination as they move from flower to flower.

Leafcutter bees are particularly interesting to observe because they don’t look or behave exactly like the familiar honey bee. They may carry pollen on the underside of their abdomen rather than on the hairy legs used by honey bees.

That makes a sunflower patch an excellent pollinator observation station.

Instead of simply asking students, “How many bees do you see?”, try asking:

What is the bee doing?

Is it collecting pollen? Moving between flowers? Feeding on nectar? Cutting a leaf? How does its behavior change as you observe it?

Those simple observations can turn a garden into a science laboratory.

Grow Your Own Sunflower Pollinator Station

Sunflowers are one of the easiest flowers for beginning gardeners to grow, making them particularly well suited to school gardens and home gardens.

Start with seeds.

In Florida, sunflowers can be grown nearly year-round, but the best planting time depends on where you live. In North and Central Florida, plant seeds in late winter through spring or again in late summer and fall. In South Florida, sunflowers can be planted during the cooler months, generally from fall through early spring. Check your local planting calendar for the best timing in your area.

Choose a location with plenty of sunlight and well-drained soil. Keep the soil consistently moist while seeds are germinating. Once established, sunflowers are generally fairly easy to care for.

For a classroom garden, consider planting several varieties. Different heights, colors, and bloom times can make the garden more interesting while giving students more opportunities to observe pollinators.

Don’t clean up too quickly.

Once the sunflower blooms fade, resist the temptation to immediately remove the plants.

The developing seeds can provide an important food source for birds. If you’d like to collect seeds for next year’s garden, allow some flower heads to mature and dry before harvesting.

How to Help Leafcutter Bees

If you want leafcutter bees—and other native bees—to visit your garden, think beyond flowers.

Pollinators need food, water, shelter, and places to nest.

Try:

• Planting a variety of flowers that bloom throughout the growing season
• Including native plants whenever possible
• Avoiding unnecessary pesticide use
• Leaving some stems, leaves, and natural areas undisturbed
• Providing shallow water sources
• Adding bee nesting habitat

And remember: a few holes in a leaf aren’t necessarily a problem.

If you see neat, circular pieces missing from leaves, take a closer look before reaching for a pesticide. You may have discovered one of your garden’s most helpful visitors.

Garden Challenge: Find the Pollinator!

The next time a sunflower is blooming, spend five minutes observing it.

Can you find a bee?

If you do, look closely—but give it space. What does it look like? What is it doing? Is it visiting the center of the sunflower? Is it carrying pollen?

If you see a leaf with small circular pieces missing, look around for a leafcutter bee.

For students, try keeping a pollinator observation journal. Record the date, weather, flower being visited, pollinator observed, and what the pollinator was doing.

You don’t need fancy equipment. A pencil, notebook, and curious mind are enough.

The Big Garden Lesson

Sunflowers demonstrate something important about gardening: we aren’t growing plants in isolation.

The flowers provide food for pollinators. Pollinators help plants reproduce. Seeds feed birds and other wildlife. Leaves provide habitat and food for insects. And gardeners get to watch all of these relationships unfold.

So the next time you see a sunflower swaying in the garden, take a closer look. There may be an entire world of activity happening on that one “flower.”

Grow a sunflower. Watch who visits. You might be surprised by the buzz!

Grow. Observe. Learn.

Whether you’re gardening at home, teaching a classroom, or simply curious about the natural world, planting a sunflower is an easy way to begin exploring pollination.

Your garden doesn’t have to be big to make a difference. One flower can become a classroom, a food source, and a habitat—all at the same time.