Fall is the best time to plant. If the plants are potted, you can plant them anytime. To be successful, you have to be sure to acidify your soil to a PH of about 5. I use aluminum sulphate for that and mulch with pine bark mulch. I have a layer of about three inches throughout the bed. In the long run this will maintain your PH level. Remember that blueberry bushes need a moist soil at all times, since the root system is somewhat shallow. You may get a few berries next year, which will improve as the years go by. It will take about three years to give you a decent harvest. Peak production is about 5 to 8 years. If you fail to acidify your soil, do not expect the plants to survive. They produce better with two different varieties. However, there are many kinds. Do your research before you settle on what to plant. Good luck with the plan.