If you are not sure about the condition of your soil, or if you just moved into a new place with no trees at all, maybe you should think about testing the soil before you shell out a lot of money which could result in total loss.
There are plenty of labs willing to do a soil test for you. Some are simple, while others are very complicated. Here is a list of labs that will do the job:
I guarantee my trees to grow if you water them regularly, and at least 95% of them should grow. If the mortality is over 5%, then you have soil problems and, I will not be held responsible for any losses.