Petrorhagia Species, Coat Flower, Tunic Flower

Petrorhagia saxifraga

Family: Caryophyllaceae (kar-ree-oh-fil-AY-see-ee) (Info)
Genus: Petrorhagia (pet-roh-RAG-ee-uh) (Info)
Species: saxifraga (saks-if-FRAG-uh) (Info)
Synonym:Tunica saxifraga
Synonym:Dianthus saxifragus


Alpines and Rock Gardens


Water Requirements:

Drought-tolerant; suitable for xeriscaping

Sun Exposure:

Full Sun


Grown for foliage


Foliage Color:

Unknown - Tell us


6-12 in. (15-30 cm)


9-12 in. (22-30 cm)


USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

Where to Grow:

Unknown - Tell us



Bloom Color:

Pale Pink

White/Near White

Bloom Characteristics:

Unknown - Tell us

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Late Summer/Early Fall

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 herbaceous stem cuttings

Seed Collecting:

Unknown - Tell us


This plant is said to grow outdoors in the following regions:

Palmer, Alaska

Seward, Alaska

Parker, Colorado

Lexington, Massachusetts

Gardeners' Notes:


On Jun 30, 2011, jrtinker from Palmer, AK (Zone 3b) wrote:

This plant is happier growing in the D4 gravel of my driveway than in my rock garden or perennial beds.


On Mar 29, 2008, altagardener from Calgary, AB (Zone 3b) wrote:

As Petrorhagia saxifraga is totally hardy in zone 3 (in this area which is subject to chinooks and no reliable snow cover), and, indeed, is one of the earliest plants to show new growth in late winter, those who have been treating it as an annual may wish to try it as a perennial.


On Feb 23, 2007, Weezingreens from Seward, AK (Zone 3b) wrote:

I've grown this plant as an annual, using it in baskets and borders. Seeds are easily harvested by cutting the spent stems, putting them head first in a paper bag, then wait for them to dry out and fall into the bag.


On Nov 28, 2002, Togetherwegrow from Milton,
Canada wrote:

I haven't grown it before but a friend grows it & just loves it! As for propagation, it self-seeds prolifically. It is very easy and reliable to grow. Looks similar to Baby's Breath but is much easier to grow.

I plan on getting it for 2003.


On Oct 28, 2002, joyceh from Stewart, MN (Zone 4a) wrote:

I've been growing one plant for the past 4 years. It is covered with pink blossoms from mid June to Mid August. I have not yet figured out a way to propagate it. Also, I live in zone 4. An update to this: I have had the first plant since summer of 98. It's now 2005. A couple of years ago I found another source and bought 6 more plants.. I found info that says propagation is by stem tip cuttings taken shortly after growth starts in spring. I have not tried this yet but plan to this spring. I have never seen any seedlings from this plant. My soil ph is 6.5 to 7.0. One catalog listed it as borderline hardy for zone 4, but it has survived some nasty winters with little to no snow cover and no mulch. This past winter has been the worst I've seen in 20+ years of gardening. If it makes it this y... read more