Fruitless mulberry is just a big weed. It grows fast, dies young and has all kinds of problems in between. Its ravenous root system robs water and nutrients from other plants and is destructive to sidewalks and other construction. They are subject to insects and diseases and usually look bad in the summer when leaves turn yellow and drop due to an inability to draw up enough water to compensate for moisture loss due to transpiration. There is more information in Howard Garrett's Texas Trees. While there look at the fruiting mulberries. Although messy, they are much better trees.