Description
Gratiola officinalis, known as hedge hyssop and sometimes sold as "summer snowflake", is a low plant with narrow, toothed leaves in opposite pairs. From June to August it carries small white flowers, often tinged or veined pink.
Hedge hyssop at a glance
| Botanical name |
Gratiola officinalis |
| Common name |
Hedge hyssop, gratiole |
| Plant type |
Low, clump-forming perennial; dies back in winter |
| Height and spread |
About 25–40 cm tall, up to 50 cm wide |
| Flowers |
White, often tinged or veined pink to purple-red, June to August |
| Position |
Full sun or part shade |
| Soil |
Boggy or wet soil, or very shallow water |
| Pond depth |
0–5 cm of water over the crown |
| Hardiness |
RHS H5 – hardy in a cold winter (-15 to -10°C) |
| Native to |
Central and southern Europe (not UK native) |
Where to plant hedge hyssop
- The very shallow edge of a pond, 0–5 cm deep
- Bog gardens and wet soil
- Small ponds, where its low size suits
Is it poisonous?
Yes. All parts are poisonous. It was once used as a herbal purgative, and in excess it can cause kidney damage, bowel bleeding and miscarriage. Do not eat it or use it as a herb, keep it away from children and pets, and take particular care if you are pregnant.
How to plant and care for it
Plant in spring or summer in wet soil or very shallow water. It is generally free of pests and diseases.
Which size should I buy?
Bare-root plants (7 cm, 9 cm, 1 litre and 3 litre) arrive without a pot or compost and are the most economical way to plant a group. Potted plants (9 cm, 1 litre and 3 litre) arrive growing in our peat-free compost and give a faster display. Packs of 3 come in 7 cm, 9 cm, 1 litre and 3 litre bare-root sizes and cost less per plant. The 2x Pot & Compost option is two plants supplied with pots and compost.
