215 gardener saves
Clethra: the varieties gardeners actually grow
We track 6 varieties; these are the ones gardeners actually save and plant, ranked by real saves rather than catalog marketing. Each links to full care, bloom, and live price data.
The 6 most-saved Clethra varieties
Of 6 in the catalog — ordered by how many gardeners actually grow them.
#1 most savedSummersweet
Clethra alnifolia 'Caleb'
#2 most savedSummersweet
Clethra alnifolia 'Crystalina'
#3 most savedRuby Spice Summersweet
Clethra alnifolia 'Ruby Spice'
Summersweet
Clethra alnifolia
Hummingbird Summersweet
Clethra alnifolia 'Hummingbird'
Einstein Summersweet
Clethra alnifolia 'Einstein'
How to grow Clethra
What the Clethra varieties in our catalog actually agree on — drawn from the care records of the 6 most-grown of them, not from a generic template.
The Clethra year
- MulchMarch, April and October100% of varieties
Maintain a layer of organic mulch to conserve moisture.
- PruneFebruary and March100% of varieties
Prune in late winter or early spring to shape and remove deadwood.
- FertilizeMarch and April67% of varieties
Apply an acid-forming fertilizer in spring if soil is alkaline.
- PlantMarch, April, September and October50% of varieties
Plant in moist, acidic soil in spring or fall.
Do
- Provide consistently moist soil.
- Mulch well to keep roots cool and moist.
- Prune in early spring before new growth begins to shape the plant.
- Plant in groups for a stunning floral and fragrant display.
- Provide consistent moisture, especially in the first year and during dry spells.
Avoid
- Avoid letting the soil dry out completely.
- Don't let the soil dry out, especially in summer.
- Avoid planting in alkaline soils, which causes yellowing leaves.
- Don't prune after new growth starts, as this will remove flower buds.
What goes wrong with Clethra
| Problem | What you'll see | What to do |
|---|---|---|
| Spider Mites | Fine webbing on leaves, stippling, and yellowing foliage, especially in hot, dry conditions. | Increase humidity by spraying with water. Apply insecticidal soap or horticultural oil. Encourage predatory mites. |
| Root Rot | Wilting, yellowing leaves, and mushy, brown roots, caused by overly saturated soil. | Ensure proper drainage at planting. Avoid overwatering. There is no chemical cure; improve soil conditions or relocate the plant. |
| Leaf Spot | Brown or black spots on leaves, usually cosmetic. | Improve air circulation. Rake up and destroy fallen leaves in autumn. Generally does not require chemical treatment. |
| None | Clethra is known for being exceptionally free of disease problems. | No action is typically required. Good cultural practices (proper siting and watering) prevent most issues. |
Making more Clethra
Division
- In early spring, dig up the entire clump.
- Use a sharp spade to divide the root ball into sections.
- Ensure each division has ample roots and several stems.
- Replant the divisions immediately and water well.
Softwood Cuttings
- Take 4-6 inch cuttings from new growth in early summer.
- Remove lower leaves and dip the cut end in rooting hormone.
- Stick cuttings in a moist mix of perlite and peat.
- Cover with a plastic dome to maintain high humidity.
- Roots should form in 4-6 weeks.
Clethra questions
How many types of Clethra are there?
The Sow catalog tracks 6 distinct Clethra varieties. The most popular — ranked by 215 real gardener saves — are shown first above.
What zones does Clethra grow in?
Across its varieties, Clethra covers USDA Zones 4–9. Individual varieties differ — each plant page lists its exact range, and Sow filters the catalog to your zone automatically.
When does Clethra bloom?
Most Clethra varieties bloom in mid-summer. Staggering early, mid, and late varieties extends the genus's season in one bed.
Which Clethra should I choose?
Start from the most-saved varieties above — popularity across thousands of gardens is a strong signal of reliability — then filter by your zone and sun. In the Sow app you can preview any of them in a photo of your actual yard before you buy.
Keep exploring
Design with Clethra in your own yard
Snap a photo of your space and see these varieties planted in it — sized correctly, matched to your zone, with care reminders included.
