Summersweet
Clethra alnifolia
Also called Sweet pepperbush and Clethra
Garden plant · ShrubsOne of the very few shrubs that flowers in AUGUST, takes wet soil AND takes shade — and it is scented enough to find with your eyes shut. It suckers gently into a thicket, which is usually what you want from it.
Care at a glance
- Ease
- Easy
- Water
- Every 3 daysWater the ground — water at the base, in the morning, not over the leaves.
- Light
- Sun to part shade, in ground that stays damp
- Feed
- Every 45 days
- Humidity
- Average to high
- Hardiness
- Hardy — a very cold winter RHS H6, to -20°C
- Size
- 2.5 m tall · 2 m across
- Lifecycle
- Shrub
- Origin
- Eastern North America
Is it safe for pets and people?
PetsNothing recorded against it
No animal-poison authority lists this plant either way.
PeopleNot checked yet
Nobody has checked this one against a source for us yet, so treat it as unknown rather than safe.
Checked against ASPCA and RHS on 2026-09-22. Where a source says nothing, we say nothing.
A guide, not veterinary or medical advice. If a pet or a person has eaten a plant and you are worried, call your vet or doctor now — don’t wait for signs to appear. Spotted a mistake? Tell us.
First signs of trouble
- Leaf edges crisping and flower spikes going over early in a dry August. This is a wet-ground shrub — in a normal border it is the first thing to complain in a drought.Drying out · disorder
- New shoots coming up a foot or more outside the clump each year. It is usually welcome; if it is not, a spade round the edge in spring is an annual job rather than a fix.Spreading thicket · disorder