Think of your yard as a room of your house. It's probably going to be the largest room you have. How much are you willing to spend to renovate a room in your house? Not everyone gets invited into your home, but everyone has the opportunity to see your front yard without invitation. First impressions are important and lasting.
According to Better Homes and Gardens, real estate studies show that property values can increase by 5-15% with improved landscaping. Therefore a budget of 5-10% of your homes value on landscaping could be recouped immediately. As trees and shrubs grow larger they increase in value over time; so will the value of your landscape.