Is it common for blueberry bushes to go dormant. . . meaning that they have produced fruit every year for four years, but one of the bushes has little or no fruit this year, just some dried looking berries where the fruit should be. The plant still looks healthy and it hasn't been damaged. The other plants in the row seem to have a normal amount of berries. The plant has about six canes growing actively.
Any fruiting plant can "take a year off" from producing, especially after they have been stressed. If this bush is on the end, it is very likely that it is exposed to elements the others are not, such as winds, direct sun and frost. All of these at the wrong time or too much can stress the plant and affect its ability to fruit.
Pests and disease can also stress a plant and make it difficult for it to fruit. A plant will sacrifice their fruit in order to refocus its energy on fighting off these problems. Because of this, I would recommend that you treat the plant with a pesticide and a fungicide, just as a precaution. I personally like neem oil as it is both a fungicide and a pesticide and is safe for people, pets and bees.
Northern high bush used to produce. Now for last 3 years, it blossoms but never has any fruit. It's in the same location and amidst other producing bushes.
This is a pollination issue. The other bushes may be self pollinating while this one needs a little help from friendly pollinators like bees. These articles may help with attracting pollinators:
https://www.gardeningknowhow.com/garden-how-to/beneficial/insect-pollination-process.htm
https://www.gardeningknowhow.com/garden-how-to/beneficial/creating-a-pollinator-garden.htm
The other issue may be that there is fruit, but it is dropping early on. This is caused by stress to the plant. It may not be getting enough water or it may have a pest or disease. Consider treating it with both a fungicide and a pesticide as a precaution and see if you can't get it some more water.
I inherited property with 50 plants, which have never been pruned. They have sprouted to a width of six feet and some branches are 10 to 12 feet high. How do I start to prune these blueberry plants?
This article should help: https://www.gardeningknowhow.com/edible/fruits/blueberries/blueberry-plant-pruning.htm
My blueberries are grainy to the taste. They are about 40 years old. They are still good and a lot of them. What should I do to them?
Allow the berries to remain on the bush a little longer. They may not be fully ripened yet. Look for a dark navel when harvesting blueberries, not the color of the fruit. Blueberries with a reddish color around the stem end are not ripe, and will be tart, or grainy. However, those left on the bush to become fully deep blue will be ripe and sweet.
When is the best time to transplant a blueberry bush?
Spring or fall are the best times to transplant blueberry bushes.
My blueberry plants are producing lots of berries, but they are all sour---any ideas?
Allow the berries to remain on the bush a little longer. They may not be fully ripened yet. Look for a dark navel when harvesting blueberries, not the color of the fruit. Blueberries with a reddish color around the stem end are not ripe, and will be tart. However, those left onthe bush to become fully deep blue will be ripe and sweet. The following article should be of some help to you: https://www.gardeningknowhow.com/edible/fruits/blueberries/growing-blueberry.htm
What do I need to do for sweeter blueberries? Last year they were very sweet, and this year they are very tart.
A common complaint with these plants is sour tasting berries. However, most people actually harvest their blueberries too early. For sweeter berries, allow them to remain on the bush a little longer. Otherwise, they may not be fully ripened. Look for a dark navel when harvesting blueberries, not the color of the fruit. Blueberries with a reddish color around the stem end are not ripe, and will be tart whereas those left on the bush to become fully deep blue will be ripe and sweet.
Raising soil acidity can also help. Pine needle mulch will help raise the soil acidity over time, but there are some other things you can try too. This article should help with additional suggestions: https://www.gardeningknowhow.com/edible/fruits/blueberries/lower-soil-ph-blueberries.htm