bee forage

Tempting blue-flowered Caryopteris makes bees soar: “We want more!”

A honey bee enjoys foraging on a Caryopteris shrub.

Caryopteris is a mint-family shrub with blue flowers and blue pollen. This late-season bloomer supplies nectar and pollen when bees need it most.

Inside: In my recent post on blue-flowered plants for pollinators, I failed to include Caryopteris, a mistake that caused a deluge of complaints. So here it is! A favorite blue-flowered plant with deep blue pollen and a passionate following of gardeners and bees.

A plant full of surprises

People often call Caryopteris “blue mist spirea,” probably because of the foliage. But unlike Spirea, a rose family plant, Caryopteris belongs to the mint family. You may also hear it called “bluebeard” or various cultivar names such as ‘Dark Knight,’ ‘Longwood Blue,’ and ‘Sunshine Blue.’

But whatever you call it, pollinators adore it, especially bees, butterflies, and hummingbirds. Because it blooms from mid-summer to fall—an especially lean time for pollinators—it becomes a hotspot for late-season nectar-seekers. In addition, it produces plenty of attractive and nutritious deep blue pollen.

We often overlook Caryopteris as a pollinator plant because it is not native. Gardeners imported it to this country from East Asia as an ornamental shrub. However, it is not considered invasive anywhere in North America.

Caryopteris x clandonensis. Public domain image
Caryopteris x clandonensis. Public domain image

In many ways, Caryopteris is a typical mint

Although it is a shrub, it has many of the features we associate with mints, including opposite leaves and square, hollow stems. However, it does not smell minty. Instead, the leaves have an enticing aroma reminiscent of cinnamon, cloves, and eucalyptus. Sometimes the leaves—dried and crushed—make a spicy potpourri.

Because the plant remains small, only 2-3 feet high, we can use it in small gardens and even containers. In recent years it has become popular as a pollinator plant where fall flowers are often in short supply.

The flowers yield delectable nectar in moderate amounts, sweet enough to attract a wide range of pollinating bees and butterflies. Like any plant, the amount of nectar varies with the local conditions and rainfall. Besides delicious nectar, copious pollen attracts bees, especially honey bees, that are stocking up for the winter.

How to grow Caryopteris

Caryopteris is easy to grow. To prevent a straggly appearance, prune it back before the next growth cycle.

  • Light: Like most mints, Caryopteris loves full sun. Although it can handle light shade, too much shade results in fewer flowers.

  • Soil: Caryopteris thrives in well-drained sandy soils with plenty of organic matter, but can tolerate poor soils after establishment. The pH should be slightly acidic to neutral.

  • Water: Caryopteris requires average moisture during the first year but becomes moderately drought tolerant after it becomes established. As such, it is frequently used in xeriscaping. Too much water can cause root rot.

  • Amendments: Apply fertilizer lightly in spring to stimulate growth and flowering, but do not use too much.

  • Pruning: Cut back stems in late winter or early spring to maintain the shape of the shrub. You can remove up to two-thirds of the growth, but be sure to leave several buds on each stem.

  • Pests: Like most mint family plants, Caryopteris is not attractive to deer or rabbits.

That’s it. Once established, your pollinator-friendly Caryopteris will delight pollinators (and people) for years to come.

Rusty
Honey Bee Suite

The popular hybrid Caryopteris x clandonensis has bright blue fall-blooming flowers.
The popular hybrid Caryopteris x clandonensis has bright blue fall-blooming flowers.

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About Me

I backed my love of bee science with a bachelor’s degree in Agronomic Crops and a master’s in Environmental Studies. I write extensively about bees, including a current column in American Bee Journal and past columns in Two Million Blossoms and Bee Craft. I’ve endured multiple courses in melittology and made extensive identifications of North American bees for iNaturalist and other organizations. My master beekeeper certificate issued from U Montana. I’m also an English nerd. More here.

15 Comments

  • How is this plant with dusty mildew? I have found peppermint and hummingbird anise mints are more resistant and have them in my mint garden, but have given up on bee balm because I regularly get mildew on it, and last year I got it on my zinnias, so I am looking for another bee-friendly plant.

    • Jennifer,

      Fairfax Gardening says, “Because of the open nature of its growth habit and its smaller leaves, it is not prone to the powdery mildew that can affect other more densely foliaged plants during hot humid periods.” However, I don’t know if powdery mildew is the same as dusty mildew.

  • I’m thinking about buying some. I don’t actually have a bucket list, but seeing bees with blue pollen should be on it.

  • Always on the lookout for new bee-friendly plants.
    Your recent article on Caryopteris caught my eye.
    Just ordered 3 plants.
    Been following you for a number of years.
    Thanks for this suggestion.

  • A few years ago I visited a nursery and honey bees were all over it so I bought two. It’s not thriving where I have it and my girls snub it! Lol. Maybe this year.

  • So off topic, i should be ashamed:

    Rusty, I just wanted to tell you THANK YOU for your website! I just got my first package of bees (I had to ship to Mississippi, supposed to be 2 day transit, it took 7 days), and your website helped me hopefully give these ladies a chance! They had already started building comb inside the package container and seemed grateful for the sugar water spray. Please keep doing what you do!

  • Thanks for all your share and all the help we all get from it.

    Do you know the hardiness zone? Will it live through some real winter?

    • Thanks, Tom.

      Caryopteris prefers USDA zones 5–9. Zone 5 has average minimum winter temperatures ranging from -20°F to -10°F (-28.9°C to -23.3°C).

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