Where in the US do blueberries grow without amending the soil?
The short answer
Blueberries want pH 4.5 to 5.5, more acidic than almost any other common garden plant. The typical topsoil is in or within 0.2 of that range in 1,320 of 3,131 counties (42%). In 527 counties the soil is calcareous and lowering it far enough is not practical; everywhere else it takes sulfur, applied over a season or more.
States where it is easiest
Share of counties where typical topsoil already suits blueberries:
- Georgia: 159 of 159 counties
- Maine: 16 of 16 counties
- Massachusetts: 14 of 14 counties
- New Hampshire: 10 of 10 counties
- Connecticut: 8 of 8 counties
- Rhode Island: 5 of 5 counties
- District of Columbia: 1 of 1 counties
- Alabama: 66 of 67 counties
- South Carolina: 45 of 46 counties
- West Virginia: 53 of 55 counties
Some of the most naturally acidic counties
- McDowell, WV: typical pH 4.42
- Charles, MD: typical pH 4.47
- Franklin, FL: typical pH 4.5
- Ketchikan Gateway Borough, AK: typical pH 4.52
- Swain, NC: typical pH 4.56
- Forest, PA: typical pH 4.57
If your county is not on the easy list
If your county page says "add sulfur", the amount depends on texture (see the rates guide), and it is worth starting the autumn before you plant, because sulfur needs warm, moist soil and several months to act. If it says "use beds or pots", believe it: the calcareous soil guide explains why sulfur cannot win there. Either way, test the actual planting spot first, as the county vs yard guide explains.