- Light
- full sun to part sun. It flowers in either, and it takes a west-facing porch in August without complaint
- Water
- low. Water when the top two inches are dry, and let it dry out between drinks. It is one of the few things that forgives a missed day
- Toxicity
- not listed by the ASPCA or Pet Poison Helpline. Neither lists Euphorbia hypericifolia or the genus as a whole; their Euphorbia entries are other species (poinsettia, pencil cactus, crown of thorns), and absence from the list is not evidence of safety. NC State Extension lists it as poisonous to people (low severity): diterpene esters in the milky sap of every part of the plant; contact dermatitis, blistering of the lips and mouth if eaten, and temporary to permanent damage to the cornea if the sap reaches an eye. NC State says to keep it away from pets and children. Wear gloves when trimming it
| Type | Warm-season annual |
|---|---|
| Sun | Full sun, part sun |
| Water | Low |
| Size | 12 to 20 in tall, 12 to 18 in wide |
| Bloom | white · May to frost |
| Plant in | mid-April to June |
| Interest | Summer, fall |
| Upstate winter | One season |
| Hardy zones | 10 to 12 |
| Use in | Containers, beds |
| Role | Filler |
Toxicity not independently confirmed: Not listed by ASPCA or Pet Poison Helpline; NC State Extension Plant Toolbox for the human warning. If you have pets, check with the ASPCA or your vet before putting this one where they can reach it.
Diamond Frost is the plant that makes everything next to it look better. It is a cloud of tiny white flowers, like baby’s breath that never quits, and it blooms from the day it is planted until frost with no deadheading. Tuck it between geraniums, coleus and petunias to soften the edges. Nobody asks what it is, but every planter with it in looks finished.
In the Upstate
It is a tender perennial hardy only to zone 10, so it is an annual here and dies at the first frost. It goes out from mid-April. Heat does not bother it. Drought does not bother it much. Deer and rabbits leave it alone. Between May and October there is very little to worry about.
In a container
Diamond Frost is a filler, 12 to 20 inches tall and about as wide, with a loose mounding shape that fills gaps without crowding neighbors. Water when the top two inches are dry. In a pot in July that is every two or three days, not daily. Pinch the tips once or twice early on if you want it bushier, and it needs no swap midseason.
Care
There is not much. A slow-release fertilizer at planting is plenty, with a light liquid feed midsummer if the pot is crowded. Wear gloves when you pinch or trim it, because the milky sap irritates skin and can hurt an eye. The one thing that kills it is a pot that stays wet, so give it a fast-draining mix and skip the saucer.
Want this planted for the light you actually have? Start a project
Where it shows up
Sources
- NC State Extension Plant Toolbox, Euphorbia hypericifolia Diamond Frost 'Inneuphdia' (plants.ces.ncsu.edu/plants/euphorbia-hypericifolia-diamond-frost-inneuphdia/)
- ASPCA toxic and non-toxic plant list, searched for Euphorbia (aspca.org)
- Pet Poison Helpline, searched for euphorbia (petpoisonhelpline.com)
