Trees need a lot of essential nutrients to survive the cold weather, including nitrogen, potassium, magnesium, and water. In order to make sure that your tree receives all of these important nutrients during wintertime, it is recommended that you fertilize it at least twice per year with a high-quality fertilizer. Additionally, water the tree regularly and keep its soil moistened so that it can access moisture in freezing conditions.
Make sure to monitor your tree's health throughout winter by checking for signs of malnutrition or disease. If there are any problems detected early on, then appropriate actions can be taken to help restore balance and ensure survival through this harsh season.