The time of year when blueberries are ready to pick varies with the variety and the region. By planting different varieties, the harvest season can be dramatically extended in many locations. Check with your local extension office for varieties recommended in your region.
In Michigan, where production of the highbush blueberry is number one in the nation, more than 20 varieties are grown. This wide range of cultivars allows harvesting to go on from late June through the month of October.
Highbush varieties vary from location to location. For example, blueberries can be harvested beginning in mid-July throughout August in New Hampshire. In Alabama, rabbiteye blueberries are more common. They are harvested from early June through August.
The best determination for when to harvest blueberries is color. Fully ripe berries are blue at the calyx end and at the stem end. If a berry is blue on top at the stem, but red or green on the bottom, it is not ripe. Blueberries do not ripen further once picked.