Gomphocarpus Species, Arizona Milkweed, Swan Plant Milkweed, Tennis Ball Bush

Gomphocarpus fruticosus

Family: Apocynaceae (a-pos-ih-NAY-see-ee) (Info)
Genus: Gomphocarpus (gom-fo-KAR-pus) (Info)
Species: fruticosus (froo-tih-KOH-sus) (Info)
Synonym:Asclepias fruticosa



Tropicals and Tender Perennials

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Full Sun

Sun to Partial Shade




Foliage Color:

Medium Green


4-6 ft. (1.2-1.8 m)


36-48 in. (90-120 cm)


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)

Where to Grow:

Unknown - Tell us


All parts of plant are poisonous if ingested

Bloom Color:

White/Near White


Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Spring/Early Summer

Mid Summer

Other details:

Unknown - Tell us

Soil pH requirements:

Unknown - Tell us

Patent Information:


Propagation Methods:

From softwood cuttings

From seed; direct sow after last frost

Seed Collecting:

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

Remove fleshy coating on seeds before storing

Properly cleaned, seed can be successfully stored


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

Tempe, Arizona

North Little Rock, Arkansas

Arroyo Grande, California

Carlsbad, California

Long Beach, California

San Diego, California

Solana Beach, California

Port Saint Lucie, Florida

Barbourville, Kentucky

New Milford, New Jersey

Elizabeth City, North Carolina

Austin, Texas(2 reports)

Alexandria, Virginia

show all

Gardeners' Notes:


On Sep 10, 2015, Domehomedee from Arroyo Grande, CA (Zone 9a) wrote:

I like this plant as it creates food for the Monarch butterfly larvae. It grows large, mine is a good five foot tall, but not so big as it's cousin "Hairy Balls" milkweed which I don't like as it is so big it is a major project to cut it back in winter. Gomphocarpus makes a lot more leaves so I don't run out of food like I have in the past with just he Asclepias curassavica in the "Butterfly Garden". I have Monarchs in all stages on it, from eggs to cocoon.


On Jul 20, 2014, Alittlepatchofheaven from Port Saint Lucie, FL wrote:

This is an amazing plant and I can not figure out why it is not available in nurseries! It has deep roots and petite white/purple flowers! It grows quite tall (mine are as tall as 5 feet), likes full sun, tolerates FL heat, and is relatively drought tolerant. I have a garden just for monarchs and this is my favorite milkweed! Monarchs and Queens love to lay eggs on the leaves and munch on it! So much that I have not had any of the seed pods develop yet. I just ordered more seeds online because I want more of this milkweed!!!!

I started my plants from seed from one of my generous neighbors and it was very easy. I have had them for about 18 months.


On Oct 23, 2012, fulxmom from Long Beach, CA wrote:

So glad to find this picture. I have this plant and it had been mislabeld as Swamp Milkweed. The ball shaped seed pods create lots of interest as people walk past my front yard. I did let it get a little too tall but need to wait til this growing season is over to begin a cut-back. Grows quickly


On Jun 25, 2009, kittysue from Fairborn, OH wrote:

If cultivated (watered regularly, no competition), this species blooms it's first year and will produce seed pods. The pods begin to get a slight brownish color but remain mostly green when it opens. The seed disperses within the first hour of opening, and quicker if a wind is blowing. In a very light wind, the seed shouldn't travel very far ~ 10 feet.


On Sep 18, 2006, CaptMicha from Brookeville, MD (Zone 7a) wrote:

So far, so VERY good.

It seemed that every single seed that touched the soil germinated. I don't think I lost any seedlings to drying out, dampening off, repotting, etc.

I hope these hardy little plants will survive the winter in a sunny window so I'll have more to comment on next year.

*Note* Pinch the tops otherwise they'll grow very tall without many branches.


On Jun 12, 2002, Ulrich from Manhattan Beach, CA (Zone 11) wrote:

Easily raised form seed. Matures within two years. Fruits are about 2.5 inches diameter and light as air.