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.
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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.
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.
Honey Bee Suite