Unlike meat proteins, which are fully cooked anywhere between 140 and 165°F (60 to 74°C) or so, vegetables contain pectin, a kind of glue that holds their cells together and keeps them firm. Pectin doesn't break down until 183°F (84°C), which means that no matter what vegetable you cook sous vide, you have to set your water oven to at least 183°F if you would like the end results to be tender.
 

Carrots - 60 min - 85°C

The following vegetables will do equally well with the exact same recipe:

• Small onions (like cipollini or pearl onions), peeled
• Small radishes, scrubbed of dirt and stems trimmed to 1/4 inch, or large radishes, cut into 1-inch pieces
• Small turnips, peeled and stems trimmed to 1/4 inch, or large turnips, cut into 1-inch pieces
• Parsnips, peeled and cut into 1-inch pieces
• Baby artichokes, trimmed and quartered