Autumn is a beautiful time of year when the leaves on many trees and shrubs turn vivid shades of red, orange, yellow and purple. One particularly eye-catching shrub that develops pink foliage in the fall is the seven son flower (Heptacodium miconioides). In this article, we’ll take a close look at this unique plant and why its leaves blush pink when cooler weather arrives.
Overview of Seven Son Flower
Seven son flower is a large deciduous shrub that can grow up to 15 feet tall and wide. It is native to China and was introduced to Western gardens in 1907. The common name “seven son flower” comes from a Chinese legend that the plant had seven sons who were transformed into the seven flowers the shrub produces.
Some key facts about seven son flower:
- Blooms late summer to early fall with fragrant white flowers that attract butterflies and bees
- Features elongated, oval green leaves that turn brilliant shades of pink, red and purple in autumn
- Grows in zones 5-9 in full sun to part shade
- Prefers moist, well-draining soil but is adaptable to different soil conditions
- Low maintenance shrub, only needs pruning every few years to maintain shape
The striking blossoms and fall foliage make seven son flower a great choice for borders, foundations, containers or as a specimen planting. Next, we’ll look at why the leaves turn pink in the fall.
Why Leaves Turn Pink in Autumn
In the spring and summer, seven son flower leaves are green with a fuzzy white underside. But as daylight hours shorten and temperatures cool in fall, the leaves transition to vivid pinkish-red tones. This color change is the result of chemical processes that take place inside the leaves.
During the growing season, chlorophyll gives leaves their green pigment. Chlorophyll helps plants convert sunlight into energy through photosynthesis. In autumn, lower light levels and colder weather cause the chlorophyll in leaves to break down and disappear.
This reveals other colorful pigments called anthocyanins that were present in the leaves all along, but masked by the green chlorophyll. Anthocyanins produce red, blue and purple hues in plants. The specific pinky-red pigments in seven son flower are called pelargonidins.
Why Do Anthocyanins Form?
Plants produce anthocyanins in response to stresses like bright sun exposure, injury, or nutrient deficiency. Anthocyanins act as antioxidants that protect leaf cells and tissues. They also attract pollinators to flowers.
As winter nears, anthocyanins help recycle nutrients from leaves back to the plant. The vivid fall show seven son flower puts on is the result of anthocyanins that developed during the growing season fully revealing themselves.
Where to See Seven Son Flower Fall Color
One of the best places to enjoy seven son flower’s autumn display is at botanical gardens and arboretums, where mature specimens put on a showstopping display. Here are some top spots in the U.S. to see seven son flower foliage turn pink:
|Chicago Botanic Garden
|Franklin Park Conservatory
|Missouri Botanical Garden
|St. Louis, MO
|United States National Arboretum
|Atlanta Botanical Garden
You can also find seven son flower at many retail and online nurseries if you’d like to grow it in your own landscape. Combine it with other shrubs like hydrangea and viburnum that also change color in the fall for a spectacular display.
How to Grow Seven Son Flower
Here are some tips for successfully growing seven son flower in your garden:
- Choose a spot with full sun to part shade and fertile, well-draining soil.
- Give each shrub 6-10 feet of space to grow when planting multiple specimens.
- Dig a hole twice as wide and deep as the root ball.
- Set the plant in the hole and backfill with native soil, watering thoroughly after planting.
- Mulch around the base with 2-3 inches of bark chips or shredded leaves.
- Water 1-2 times per week during the first year to establish an extensive root system.
- Fertilize in early spring with a balanced 10-10-10 fertilizer or compost.
- Prune every 2-3 years in late winter to shape and remove dead wood.
- Remove spent flower clusters after blooming to encourage more blooms.
- Watch for powdery mildew disease and treat with neem oil if needed.
With proper siting, planting and care, you’ll be rewarded with years of beauty from seven son flower. The pink-blushed fall foliage is sure to brighten up your landscape.
Companion Plants for Seven Son Flower
There are many great options for companion plants that complement seven son flower’s ornamental qualities and also enhance the fall garden:
- Hydrangea – especially oakleaf, panicle and smooth hydrangeas turn red and burgundy
- Viburnum – develops red and purple fall color
- Fothergilla – foliage turns vibrant red and orange
- Asters – purple and magenta flowers in fall
- Goldenrod – bright yellow plumes
- Sedum – red flowers and foliage
- Helenium – coppery-orange daisy flowers
- Switch grass – airy pink plumes
- Maiden grass – tan seed heads
- Purple moor grass – reddish-purple foliage
Grouping seven son flower with plants that have coordinated fall hues makes for captivating combinations. You can also underplant it with spring bulbs like daffodils that bloom before the shrub leafs out.
If you’re looking to add some eye-catching color to your fall garden, seven son flower is a superb choice. The unique shrub provides fragrant summer blooms, vivid pink autumn foliage and great structure all year round. Add it to borders and beds along with other plants that shine in autumn for unforgettable fall displays. With its graceful arching branches adorned in pink finery, seven son flower is sure to be a prized addition to any landscape.