I don't think age has much to do with sweetness or flavor. There are some varietal differences. Also sweetness improves as the berry hangs longer. This spring the sweetness of Star and Santa Fe improved 6-8 weeks after the first berries turned blue. On my Southmoon the berries have been hanging even longer and the flavor and sweetness are still improving.

I also think that too much water and nitrogen leading up to harvest can lower flavor and sweetness. This is true with most fruits.

The Fruitnut

Fruitnut,
Are you able to identify a variety by appearence? If I were to send you a picture of my blueberry bushes would you be able to tell me what variety it is? I was given these bushes by an elderly lady who has since passsed away and have no idea what variety they are.

One thing you can do with blueberries that aren't quite ripe is use them to make cobbler. Add sugar as necessary. I have developed a taste for blueberries with a bit of red showing on the base, since I am competing with our local birds to see who is first. We have 6 different varieties of blueberry here, and sweetness is never a problem. I think there is something missing in your soil, but I'm not sure what. Are the mature leaves deep green? They will be light green when they emerge, and in about 2 months, they should turn deep green. I started growing blueberries in our yard, back in 1995. Every year, in the early spring, each shrub gets a tablespoon of Miracle-Grow for "acid loving plants" dissolved in water, per the instructions. This year I switched to Schultze's Plant Food, for "acid loving plants," because that is what I could find locally. In addition to nitrogen, phosphorous, and potassium, the big three, both of these formulations contain small amounts of trace nutrients, like boron, copper, iron, manganese, molybdenum, and zinc. There is no reason to use too much of these multi-element fertilizers. Since our shrubs are heavy with fruit this year, I did a second application in the late spring. That's all they'll get this year. Sugar is produced in the leaves, and if a needed nutrient is missing, the plant metabolism will be reduced. Laboratories exist that can analyze your leaves for all the essential elements, but it would likely be less expensive to pick up some Miracle-Grow, and apply per the instructions.

No, I won't be able to identify your variety. The fruit usually looks pretty much the same.

Another factor that can reduce sweetness is too much fruit relative to the leaf area. If a variety doesn't get enough chilling it can set a lot of fruit but it may not leaf out well. Also some varieties can just be prone to setting too much fruit. The cure may be as simple as pruning heavily. This will reduce the amount of fruit and increase vegetative growth, ie leaves.

If your plants are old and lack vigor, prune out the largest half of the shoots.

The Fruitnut