Answer: The plants of both are usually available bare root or in containers in the spring, but you could conceivably plant container grown stock in the early fall. Your county extension should be able to help you in selecting the best varieties for your area.
Blueberries require a very acid soil that is rich in humus, stays evenly moist and yet is well drained so it is never soggy. You should test your soil and consult with your county extension on interpreting the results and modifying your soil specifically to grow blueberries. The shrubs usually take a number of years to begin to bear, perhaps about five years or so.
Blackberries would not do well in a soil that acid, so they would need to be planted in a separate area. They also tend to be large plants so you will need to plant for their spacing and a means of supporting them to keep them in bounds. The plants take about two years to come into full production.
(I do not seem to have a specific listing for Jefferson County however the state number for Rutgers Cooperative Extension in New Brunswick is 908 932 9306; they should be able to direct you or the local number should be in your local phone book.)
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