Gardening Question:
The garden section of one of my magazines referred to a planting of tweedia. It looked beautiful, but I can’t find the plant listed in any of my gardening books. Can you tell me a little about it?
Answer:
Even gardening books that talk about this plant, Tweedia caerulea, usually use its former name, Oxypetalum caeruleum. It is also called southern star and blue milkweed, since it is a member of the milkweed family. It is a native of the tropics of South America, so must be grown as an annual in the United States. Not really a vine but more of a subshrub, it has twining stems to three feet tall. Its most spectacular feature is its flower color, described as a powder blue tinged with green that makes it almost turquoise, becoming lilac as it ages.