Brianna: It would have been better to buy a tree last summer rather than this summer  The one we bought this summer is struggling to survive this summer' s drought  If we had bought one last summer, it would have been able to survive this summer' s drought, because last summer' s normal rainfall would have enabled it to develop established roots
Trees with established roots can better withstand droughts
If a tree had been purchased last summer, it would be better able to survive this summer's drought.