Cow's Horn

Euphorbia grandicornis

Family: Euphorbiaceae (yoo-for-bee-AY-see-ee) (Info)
Genus: Euphorbia (yoo-FOR-bee-uh) (Info)
Species: grandicornis (gran-dih-KOR-nis) (Info)
View this plant in a garden


Cactus and Succulents

Foliage Color:

Unknown - Tell us

Bloom Characteristics:

Unknown - Tell us

Water Requirements:

Drought-tolerant; suitable for xeriscaping

Where to Grow:

Unknown - Tell us


4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)

12-15 ft. (3.6-4.7 m)

15-20 ft. (4.7-6 m)


36-48 in. (90-120 cm)

4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)

10-12 ft. (3-3.6 m)


USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Full Sun


Handling plant may cause skin irritation or allergic reaction

Bloom Color:

Pale Yellow


Bloom Time:

Mid Spring

Late Spring/Early Summer




Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

From semi-hardwood cuttings

Allow cut surface to callous over before planting

Seed Collecting:

Unknown - Tell us


This plant has been said to grow in the following regions:


Phoenix, Arizona (3 reports)

Clayton, California

Hayward, California

Perris, California

Reseda, California

San Diego, California

San Marino, California

Spring Valley, California

Thousand Oaks, California

Bartow, Florida

Fort Walton Beach, Florida

Andrews, Texas

Weslaco, Texas

show all

Gardeners' Notes:


On Jan 23, 2015, poeciliopsis from Phoenix, AZ wrote:

Central Phoenix -- Euphorbia grandicornis seems remarkably hardy. I have one that grows in the ground in full winter shade and partial summer sun, with once-a-month summer water. It is etiolated but healthy -- about 3 feet tall and has just started a new branch near the base. This plant is not thought to be very frost hardy, and mine is covered by a 6 foot tall fabric cold frame in winter. Even so, my E. grandicornis has survived some freezes so harsh the elephant food (Portulacaria afra) right next to it was killed.


On May 17, 2014, Baja_Costero from Baja California
Mexico (Zone 11) wrote:

Well armed, durable Euphorbia. Tends to branch low down instead of growing a tall main trunk. This behavior is especially apparent in seedlings. Seasonal growth pattern, almost all in spring and summer, but very fast when given space and water. Nice yellow flowers. Plant may be self fertile.


On Mar 25, 2014, Mudbug1960 from Austin, TX (Zone 8b) wrote:

I had three potted grandis, each 3-4' tall, and each well-rooted for over a year. Austin dropped to 33 degrees on November 14th, cold weather was on the way, so the next day I got my frost-intolerant plants inside, including the grandis. I lost all of them, and the death spiral commenced almost immediately.


On Feb 18, 2011, Porphyrostachys from Portland, OR (Zone 8b) wrote:

Just recently noticed that the flowers have a sweet scent similar to that of Narcissus! A plant kept in an enclosed greenhouse had me thinking there was a misplaced flat of bulbs, but as I sniffed around, the culprit turned out to be E. grandicornis!


On Sep 22, 2005, BayAreaTropics from Hayward, CA wrote:

Shrubby and makes a great barrier plant. Moderate grower. Buy at the largest size you can-save a decade. The average Bay Area winter is no problem for a in ground plant.


On Nov 30, 2004, smiln32 from Oklahoma City, OK (Zone 7a) wrote:

Upright branching habit to 5-6'. Frost free areas only. Can be cut and kept short or be allowed to grow tall.


On May 13, 2004, cactus_dude from Weslaco, TX (Zone 10a) wrote:

These grow wild here in South Texas. They are also called Zig Zag Cactus. If you have goats or cattle, they will eat this plant on the edges , trying to avoid the spines. It seems the latex doesn't bother or irritate the animals, truely weird!


On Mar 26, 2004, palmbob from Acton, CA (Zone 8b) wrote:

Common potted and landscape plant in Southern California. Has great angularity and large spines making in a good ornamental choice. Does tend to rot easily if overwatered (found that out). Is not that delicate, though, in terms of brushing up against it and damaging it releasing sap... you have to hit it pretty hard. However, the spines can be quite hazardous, making moving or trimming this plant a chore. Plant can become enormous, often collapsing under its own weight eventually. However, if kept pruned regularly, this can be avoided. Makes tiny leaves in summer where the new growth forms, but usually devoid of leaves all winter. Flowers and fruits in late spring... flowers are actually quite striking and brilliant yellow, but usually on mature plants, and mostly those growing in ... read more


On Aug 28, 2003, Happenstance from Northern California, CA wrote:

Like all Euphorbia HANDLE WITH CARE, the latex/sap is dangerous and can cause skin rash, itching and general discomfort.