What time of the year does a fruitless mulberry tree start to leaf out? I’m in West Texas*

Answer 1

The species vary in the time of year they begin to leaf-out. White mulberries generally come out in early spring, almost two months before black mulberries.
You can contact your County Extension Service and see if they can give you a specific timeline in your specific area.
https://www.gardeningknowhow.com/extension-search