I brought in my three dipladenias this month, and one of them has started to vine.
Should I prune or cut back the thin shoots / vines now?
There’s no trellis as these were mounding.
Thank you for contacting Toronto Master Gardeners about your dipladenia that seems happy enough to be vining.
Whether to prune the vine at all depends on whether you like the mounding/bush shape of the plant or whether you might enjoy adding a support and train the vine to climb (Dipladenia vining habit is downwards but you could see what happens). If you want to keep the shape you have, then prune the vine now rather than wait until spring when removing it would also remove flower buds. Please wear gloves when handling dipladenia as the foliage contains a milky white oil that can irritate human skin .
Here’s hoping for some glorious plants next spring that you have successfully overwintered. Thank you for contacting us .