BALLOON PLANT MILKWEED Asclepias gomphocarpus physocarpa
Gomphocarpus physocarpus, previously known as Asclepias physocarpus (it's name was changed in 2001), is an undershrub Milkweed perennial that can grow to over six feet! The plant blooms in warm months. It grows on roadside banks, at elevations of 2800 to 5000 feet above sea level. The plant prefers moderate moisture, as well as sandy and well-drained soil and full sun.
The flowers are small, with white hoods and about 1 cm across. The follicle is a pale green, and in shape an inflated spheroid. It is covered with rough hairs. It reaches three inches in diameter. The leaves are light green, linear to lanceolate and 3 to 4 inches long, 1.2 cm broad. The brown seeds have silky tufts.
Seeds are rare and difficult to find.
Type: Hardy perennial
Height: Up to 6 feet!
Location: Sun or part sun
Hardiness zones: 8-10
Note: This plant species is known to have toxicity. Ingestion of these seeds or this plant can cause illness such as vomiting or diarrhea. This plant family is known to cause dermatitis in some individuals. The juice or sap of these seeds or this plant may cause a skin rash or irritation. The use of gloves when handling may be beneficial.
Seeds per pack: 10
Germination: As with many perennial seeds, these seeds can benefit from a period of moist cold to help them grow. This is done by giving them a cold 'winter' period (artificial or natural), and then a warming to simulate 'spring', and time to grow! Here's how this can be done:
Obtain a planting container that has holes in the bottom for excess water to drain. Place the seeds just under the surface of your growing medium, and water. Place your container in a cold area (but not freezing, perhaps a refrigerator) for 4-6 weeks. Once the cold period is completed, place the container at room temperature for them to germinate. Be sure to keep the soil moist during this entire germination period. Seedlings will sprout a few weeks, or occasionally several months, after the warming period.
If you are planting your seeds in late winter or spring, these seeds can be planted outdoors while it is still cool out (once the ground is workable and unfrozen), to receive the cold period naturally in the garden.