This is most commonly a sign that your tree is a deciduous tree! Deciduous trees lose their leaves in autumn, often turning reds, purples, oranges and yellows. Some varieties will turn a brownish colour, but all will sprout new growth in the spring. If your plant has leaves changing colour in later winter, spring or summer, this could be a sign of a nutrient deficiency, water logging or water stress. In this case talk to your local nursery or get in contact with us for advice.