A fresh-cut Christmas tree can typically last for several weeks if properly cared for. The key to prolonging its life is to make sure it has enough water. The tree will naturally lose moisture through its needles, so it's important to keep the water reservoir filled and make sure the tree doesn't dry out. Additionally, keeping the tree away from heat sources like fireplaces and radiators will help prevent it from drying out too quickly. With proper care, a fresh-cut Christmas tree can last anywhere from 4-6 weeks.