It is hard to be more specific than to say you should water as often as is required :-) A number of variables will factor into the frequency - how moisture retentive the soil is, temperatures, frequency of rainfall, whether the plant is mulched or not.

Blueberries prefer evenly moist soil - not too wet but not allowed to dry out. That may require watering as often as once a week (or more often) or as infrequently as monthly if we have a late, rainy summer. It is always a good idea to check the soil frequently and water deeply as needed. A good thick organic mulch will help to conserve soil moisture.

Blueberries are one plant you dont want to dry out.This time of year it should need little to no watering,but in the summer you should water every week.Forget the mulch thats a warm weater thing,in the northwest it just gives bugs a place to live and really isnt needed.

Sorry, but I am going to disagree on the mulch. Mulching your garden is one of the best things you can do for it for any number of reasons. Organic mulches contribute to soil texture and fertility as they decompose, they help to retard weed development, they retain soil moisture by reducing evaporation and they provide insulating properties by helping to protect against wide temperature swings (stays warmer in winter and cooler in summer). Mulch can retard the spread of diseases by reducing the splashing of fungal spores onto foliage, they prevent crusting of the soil during dry periods, allowing for better water penetration and guard against compaction. Plus there are aesthetic considerations as well - a well-mulched garden looks tidy and well-tended and lowers routine maintenance.

It doesn't matter where you live, the benefits of mulching your garden far outweigh any drawbacks or not mulching at all.

And you can never water effectively based on a predetermined timetable. Water as needed.

Yep. Who rakes up the mulch in nature? Only plants adapted to barren lands, tulips and bearded irises for instance grow well in exposed soil, may be bothered by plant litter on or around them.