There are a few things you need to take into consideration when planting fruit trees. The first is your location and the weather or climate at your particular location. Each country, state, parish, province has their own unique weather conditions. Most fruit trees do not do well in cold periods such as when the soil is below 50 degrees Fahrenheit and in fact, prefer tropical temperatures. Hence if you live in an area that is always cold such as in the Northern parts of Canada, it may serve you well not to plant fruit trees. The late spring, fall and early summer are great times to plant fruit trees because it ensures the trees at least 8 hours of sunlight daily.
There are also fruit trees that are appropriate for a particular fruit tree. Cherries and berries may be appropriate for one season while mangoes and bananas may not be appropriate for that same season. Hence, the point here is to firstly decide on which fruit trees you will be planting and research on the right seasons for them to be planted. General research shows that bare-root fruit trees should be planted in early spring and fruit trees with a burlap-covered root ball in early fall.
The next thing you want to take into consideration is the soil. You need to plant fruit trees when the soil is ready. The soil is ready when it is moist, fertilized, has a good alkaline or acidic base, is not water logged and as such is well drained. If your soil lacks any one of these conditions, it is not ready and needs to be fixed before you can even attempt to plant fruit trees.
Relating to the soil is water; if you live in areas prone to drought and water shortages, you have to take these two things into serious consideration before you can embark on planting fruit trees. Think of ways you can solve this problem. If you have water shortages or lock offs; do you have a water tank that will be able to keep your planted fruit trees watered? If not, how often is your rainfall or lack thereof (drought)? Does your schedule allow you to water these fruit trees on a daily basis? They need to be watered at least twice daily when they have just be planted.
If you are able to deal with all of these issues, provided that the general weather conditions you live in are favorable and you know which fruit trees to plant, then go ahead and plant them. Happy planting!