Coastal Sweetpepperbush
Clethra alnifolia
- Native to:
- Canada, United States, Virgin Islands
iNaturalist: © m_chasse (iNaturalist #30462946)
Taxonomy
- Division:
- Magnoliophyta | - Flowering plants
- Family:
- Clethraceae
- Genus:
- Clethra
- Species:
- Clethra alnifolia
- USDA Symbol:
- CLAL3
Growth Characteristics
- Life Cycle:
- Perennial
- Growth Habit:
- Shrub
- Height:
- 300 cm
- Light Requirements:
- Full Sun,Part Shade,Shade
- Drought Tolerance:
- Low
- Bloom Months:
- jul,aug,sep
- Bloom Colors:
- white
- Landscaping Shrub:
- Yes
Wildlife Benefits
- Bees:
- ★☆☆☆☆ Documented bee visitation (GBIF)
- Butterflies & Moths:
- ★★★☆☆ Documented Lepidoptera association (GBIF)
- Caterpillars:
- ★★☆☆☆ Recorded caterpillar host plant (HOSTS Database)
- Hummingbirds:
- ★☆☆☆☆ Documented hummingbird visits (GBIF)
Keystone Species Ranking
- Caterpillar Keystone:
- ★★☆☆☆ Butterfly & moth species supported by this genus (NWF)
Host Plant for Caterpillars
bold-feathered grass moth (Herpetogramma pertextalis), Cleahtrea nola moth (Nola clethrae), Gypsy moth (Lymantria dispar), Herpetogramma thestealis, Isabella tiger moth (Pyrrharctia isabella), Olethreutes inornatana, Prochoerodes transversata
Reported Fauna Sightings
Bees: American bumble bee (Bombus pensylvanicus), Common eastern (Bombus impatiens), Eastern Carpenter Bee (Xylocopa virginica), Southern plains bumble bee (Bombus fraternus) Hummingbirds: Ruby-throated Hummingbird (Archilochus colubris) Moths:Atteva aurea, Yellow-shouldered Slug Moth (Lithacodes fasciola) Butterflies:Eastern Tiger Swallowtail (Papilio glaucus), Gray Hairstreak (Strymon melinus), Red-banded Hairstreak (Calycopis cecrops), Silver-spotted Skipper (Epargyreus clarus), Spicebush Swallowtail (Papilio troilus), Summer Azure (Celastrina neglecta), White Admiral (Limenitis arthemis), White M Hairstreak (Parrhasius m-album)
Garden & Ecology Notes
- Wildlife Value:
- bees, butterflies, birds
- Fragrant:
- Yes
- Fall Color:
- yellow
Soil Requirements
- Soil Type:
- moist, rich, acidic loamy soil
- pH:
- 5.0 - 6.5 (acidic to slightly acidic)
- Drainage:
- tolerates poor drainage
- Moisture:
- consistently moist
- Notes:
- Thrives in wetland areas and along stream banks.
Propagation & Germination
- Stratification:
- Cold/moist stratification required — 30–60 days
- Germination Time:
- 30–90 days
- Notes:
- Seeds require cold stratification for 30-60 days; sow on surface and keep moist.
Pre-treatment: Seeds are cold stratified for 30 days. Cuttings are cut to 4 to 6" lengths with at least 2 nodes, having an angled cut on the bottom and a straight cut on the top and leaves are trimmed to approximately 50%. The bottom of the cuttings are dipped in Hormodin 1 (0.1% IBA) powder.
Establishment: Cuttings are collected from wild populations in Central New Jersey in June and early July from healthy plants. The cuttings are kept moist and placed inside a soft insulated bag used for field collections.
Source: npn.rngr.net
ORGHPS Germination Guide: Sow @ 4C for 3 months, then place @ 20C for 3 months. Requires light / surface sow (fine seed).
Where to Buy
Nationwide Seller
- Sheffield's Seed (seeds)
- Sheffield's Seed (seeds)