Ask Mr. Smarty Plants

We found two members of the genus Tradescantia native to Indiana in our Native Plant Database: Tradescantia bracteata (longbract spiderwort) and Tradescantia ohiensis (bluejacket). That doesn't necessarily mean those are the species you have in your garden, they are just good examples to look at. We really couldn't find an answer to your question. At the Lady Bird Johnson Wildflower Center, they grow profusely, but I do notice they seem usually to be in a situation where there are rocks to lean against. We have a lot of rocks on the grounds of the Center! Both of the above species are mentioned as having "stout" stems or "upright" stems. About the only suggestion we can make is paying attention to their cultural requirements. They do not require much water, and they do like shade. Their flowers open in the morning and close as the day goes on, so perhaps they are drooping over in protest against too much sunlight. Once they have ceased blooming in the summer, they can be cut back severely, and other plants, perhaps annuals, can be interspersed to keep the area attractive. Since they are perennials, they will come back and, of course, spread. In some places, they are considered invasive, so you do need to be conscious of where they are going. 

Tradescantia bracteata

Tradescantia bracteata

Tradescantia ohiensis

Tradescantia ohiensis