Clethra alnifolia (2021)

Source: Wildflower.org

Close up of flower
Clethra alnifolia picture a

Source: Wildflower.org

Clethra alnifolia picture b

Source: Missouri Botanical Garden 

Latin name: Clethra alnifolia
Common name: Summersweet Clethra 
Flowers: Showy, fragrant white/pink flowers that occur in 2-6” racemes 8
Fruit or cones: Showy, brown, persists through winter 10,8
Height & Width: 3-8’ ft. high, variable spread 8
Type: Deciduous 12
Habit: Densely rounded shrub and often suckering, resulting in large colonies 8
Wetland indicator category**: FAC, FACW 17
Texture: Coarse 16
Growth rate: Moderate 16
Light: Full sun to part shade, tolerates heavy shade 12
Moisture: High, yet drought tolerant 12
Soil*: Provide acid (pH<6.8), moist, well- drained soils 10,12
Zones: 4 to 9 8
Origin: United States east coast, Maine to Florida to coastal Texas 8,16
Ecosystem benefits: Ornamental, fragrant, outstanding fall color; bees, butterflies, and hummingbirds use flowers; provides food for wildlife 10

Features: This shrub is an amazingly adaptable plant 8. It is very ornamental and fragrant, with outstanding fall color. It attracts bees, butterflies, and hummingbirds and provide food for some mammals 10. Offers multiple seasons of interest with its spring foliage, summer blooms, yellow fall color, and exfoliating bark in winter 7.

Siting: Great choice in a shrub border, along streams and ponds, or in large masses by the edge of woodlands 8.

Care: Plant so root flare is visible at soil surface 14. At planting, water the root ball daily with two gallons of water per inch of trunk diameter for two weeks, every other day for two months and then weekly until established. Modify water recommendations to reflect site drainage and rainfall. Apply 3” of mulch over the planted area. Do not allow mulch to touch the trunk 14.

Pests: Damage caused by spider mites can be severe on plants in hot, dry locations 16. Plants are relatively pest resistant if cultural preferences are met 10,12.

Author: Owen Lancaster

Sources:

  1. Armitage, A. (2001). Armitage’s manual of annuals, biennials, and half-hardy perennials. Portland, OR: Timber Press.
  2. Armitage, A. (2006). Armitage’s native plants for North American gardens. Portland, Oregon: Timber Press.
  3. Armitage, A. (2008). Herbaceous perennial plants: A treatise on their identification, culture, and garden attributes. Athens, GA: University of Georgia.
  4. Clemson Cooperative Extension Home and Garden Information Center.(2011). Flowers fact sheets. Retrieved from https://hgic.clemson.edu/category/flowers/
  5. Clemson Cooperative Extension Home and Garden Information Center.(2011). Groundcovers & vines fact sheets. Retrieved from https://hgic.clemson.edu/category/groundcovers/
  6. Clemson Cooperative Extension Home and Garden Information Center.(2011). Trees. Retrieved from https://hgic.clemson.edu/category/trees/
  7. Clemson Cooperative Extension Home and Garden Information Center.(2011). Shrubs. Retrieved from https://hgic.clemson.edu/category/shrubs/
  8. Dirr, M. A. (2009). Manual of woody landscape plants. Champaign, IL: Stipes Publishing.
  9. Gilman, E. F. (1997). Trees for urban and suburban landscapes. Albany, NY: Delmar Publishers.
  10. Lady Bird Johnson Wildflower Center University of Texas at Austin. (2012). Native plant information network. Retrieved from http://www.wildflower.org/explore/
  11. McMillan, P., Plant taxonomist Clemson University, personal communication.
  12. Missouri Botanical Garden Kemper Center for Home Gardening. Plant finder. Retrieved from http://www.mobot.org/gardeninghelp/plantfinder/Alpha.asp
  13. North Carolina State University (2005). Plant fact sheets. Retrieved from http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/index.html
  14. Strother, E. V., Ham, D. L., Gilland, L. (2003) Urban tree species guide: Choosing the right tree for the right place.  Columbia, SC: South Carolina Forestry Commission.
  15. University of Florida, IFAS Extension. (2011). Southern trees fact sheet. Retrieved from http://edis.ifas.ufl.edu/department_envhort-trees
  16. USDA . Plant profile. (n/d).Retrieved from http://plants.usda.gov/java/
  17. USDA. Plant wetland indicator status. (n/d). Retrieved from http://plants.usda.gov/wetland.html
  18. Vincent, E., Environmental horticulturist Clemson University, personal communication.
  19. Clemson Extension. Carolina Yards Plant Database. Retrieved from https://www.clemson.edu/extension/carolinayards/plant-database/index.html

*Soil pH is determined using a professional soil test. Contact your Clemson University County Extension service for assistance www.clemson.edu/extension/. Click on “local offices”.

**2012 Plant Wetland Indicator categories (quantitative derived) http://plants.usda.gov/wetinfo.html

Indicator CodeIndicator StatusComment
OBLObligate WetlandAlmost always is a hydrophyte, rarely in uplands
FACWFacultative WetlandUsually is a hydrophyte but occasionally found in uplands
FACFacultativeCommonly occurs as either a hydrophyte or non-hydrophyte
FACUFacultative UplandOccasionally is a hydrophyte but usually occurs in uplands
UPLObligate UplandRarely is a hydrophyte, almost always in uplands