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Crown Flower, Giant Calotrope, Giant Milkweed, Swallow-wort
Calotropis gigantea

Family: Apocynaceae (a-pos-ih-NAY-see-ee) (Info)
Genus: Calotropis (kal-LOW-troh-pis) (Info)
Species: gigantea (jy-GAN-tee-uh) (Info)

Category:

Shrubs

Height:

8-10 ft. (2.4-3 m)

Spacing:

4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)

Hardiness:

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

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Full Sun

Danger:

Parts of plant are poisonous if ingested

Bloom Color:

Purple

White/Near White

Bloom Time:

Blooms all year

Foliage:

Evergreen

Velvet/Fuzzy-Textured

Other details:

Average Water Needs; Water regularly; do not overwater

Soil pH requirements:

Unknown - Tell us

Patent Information:

Non-patented

Propagation Methods:

From herbaceous stem cuttings

Seed Collecting:

Bag seedheads to capture ripening seed

Allow pods to dry on plant; break open to collect seeds

Allow seedheads to dry on plants; remove and collect seeds

Remove fleshy coating on seeds before storing

Allow unblemished fruit to ripen; clean and dry seeds

Unblemished fruit must be significantly overripe before harvesting seed; clean and dry seeds

Ferment seeds before storing

Wear gloves to protect hands when handling seeds

Properly cleaned, seed can be successfully stored

Seed does not store well; sow as soon as possible

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed

Regional

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

Encinitas, California

San Diego, California (2 reports)

Atlantic Beach, Florida

Big Pine Key, Florida

Clearwater, Florida

Fort Lauderdale, Florida (3 reports)

Hobe Sound, Florida

Hollywood, Florida (2 reports)

Jacksonville, Florida

Key Largo, Florida

Largo, Florida

Lutz, Florida

Marathon, Florida

Miami, Florida (4 reports)

Mulberry, Florida

Navarre, Florida

Pompano Beach, Florida (2 reports)

Port Charlotte, Florida

Riverview, Florida

Saint Cloud, Florida

Saint James City, Florida

Saint Petersburg, Florida

Sarasota, Florida

Satellite Beach, Florida

Sebring, Florida

Wauchula, Florida

Wellborn, Florida

Winter Springs, Florida

Kailua, Hawaii

Kapaa, Hawaii

Kihei, Hawaii

Brandon, South Dakota

Baytown, Texas

Humble, Texas

Lake Jackson, Texas

Los Fresnos, Texas

Richmond, Texas

Rio Hondo, Texas

Spring Branch, Texas

show all

Gardeners' Notes:

8
positives
1
neutral
0
negatives
RatingContent
Positive

On Oct 17, 2013, LJGardens2 from Lake Jackson, TX wrote:

I have about six of these planted in a public memorial butterfly garden here in Lake Jackson, Tx. We will be testing them through their first winter this year. All of these were planted last spring and reached 5-6 feet tall, and really looked exquisite. We will be mulching them heavily for the winter months, and if they come through the well, may use more of them in another butterfly garden.

My early comments above are from October, 2013. I'm adding additional comments here for May, 2014. I am in zone 9a here in Texas, and five of these 6 plants died from our winter freeze this year. We aren't giving up, and have replanted them with the hope that mulching more heavily next winter might make a difference in their survival rate.

Positive

On Jun 10, 2011, margaran from (Maggie) Jacksonville, FL (Zone 9a) wrote:

This plant grows well for me in zone 8-9a. I have it in a pot through which it has rooted in the ground. It does die back every winter but returns in the spring. It's great for feeding hand raised monarchs as the leaves don't wilt as quickly as the thinner leaved asclepias.

Positive

On Jul 29, 2010, vossner from Richmond, TX (Zone 9a) wrote:

New plant for me, may not survive my zone9a winter.

JUNE 2014: still growing. While it has died to the ground every winter, it comes back from roots. It hasn't expended much but it is an easy, non-demanding plant, so for that it deserves a positive rating. Planted inground, with brutal afternoon sun and access to sprinkler system.

Positive

On May 8, 2010, PingaMucho from Miami, FL wrote:

I have about 7 of these. In both the light purple and I just found one today at Fairchild Tropical Gardens that I purchased in all White. MONARCHS LOVE THIS PLANT!!! The benefit is that the larger leaves can support more caterpillars and grows back quickly. I find myself transplanting caterpillars from my tropical milkweed to the giant milkweed. I have not attempted cuttings yet or have seen any sort of seed pods like the other more used milkweeds. It does respond well to cutting back as it produces even more shoots off the original stem.

Neutral

On Sep 17, 2009, Dinu from Mysore
India (Zone 10a) wrote:

There is a superstition here in our part of the world that this plant should not be planted inside the premise/garden willfully.

Positive

On Oct 20, 2008, Dirty_Thumbs from Clearwater, FL wrote:

This plant was purchased at a local 'Master Gardeners Show' in May of 2007. There were 3 plants in one 1 gallon pot.

I had initially planted 2 of the 3 into the ground & kept 1 in the pot. Sadly, the 2 died. I did exactly what I was told to do. The Master Gardener that sold it to me gave me a print out on planting & maintaining.

Now, the one that I left in the pot kept growing. So, late summer about 3rd week of August I planted the surviving plant in a different location & planted it in a method that I prefer. (Goes against what others would recommend)

Instead of making the hole wider then the rootball, I made it a snug fit. I prefer to put a few big rocks/stones in the bottom to allow drainage. Then I mix compost w/ Topsoil, soak it w/ water. ... read more

Positive

On Oct 24, 2006, DrNatalie from Fort Lauderdale, FL wrote:

This plant is very common in Thailand. The crown-like part is extensively used in Thai flower arrangement. It will remain "fresh" for at least 1 week or so.

Positive

On Jun 28, 2004, punaheledp from Kailua, HI (Zone 11) wrote:

I got it because monarch butterflies like to lay eggs on it, hundreds of their caterpillars ate it to it's nubs last spring, but it comes right back, quickly and stronger than ever. Mine was close to 15' and growing daily when I cut it back. Easy to propogate... stick any branch it water til it roots and stick into ground. I planted a hedge of them along the back of my property, they took immediately and are very attractive, always blooming. Leis are made from flowers here, but personally I never thought it a good lei flower. Zone 11. (UH Botony says native to tropical Asia)

Positive

On May 30, 2004, palmbob from Acton, CA (Zone 8b) wrote:

Even more giant than the giant Milkweed (Calotropis procera), this weed is also from India and is used for just about every disease that exists. It has nice, ornamental flowers, too.