Any way to make blueberries taste sweeter? (2024)

Q:

My blueberries came out tasting pretty tart this summer. Is there a nutrient Ican add or discontinue to encourage sweeter berries? These are approximately 50-year-oldbushes of three or four different varieties. For the past 14 years,earlyeach spring I generously sprinkle Holly-tone around the roots. In August,branches are thinned and pruned to keep them low enough to reach berries. Theyare healthy and bear well.

A:That's the right regimen. The fact that your plants are still growing andbearing well after 50 years tells me you're doing something right!

Some varieties of blueberries are naturallysweeter than others, but since all of yours are tart, that likely doesn'texplain it. Especially if your berries used to be sweeter than they are now,something else is going on.

The three main factors governing sweetnessare adequate sunlight, weather (especially moisture) and soil nutrition.

Sunlight-wise, is it possible that yourbushes are getting less light now because nearby trees have grown and createdmore shade?

Weather-wise, berries are actually sweeterin drier years during ripening. The fruits will be smaller, but the sugars aremore concentrated. In wet years, you might get bigger berries, but they'reusually a little more bland.

Nutrition-wise, flavor can be affected notonly by the levels of various nutrients but also by the soil pH, which affectshow well the nutrients are being broken down and available to the plant. If youhaven't done so lately, I'd run a soil test.

Do-it-yourself, mail-in Penn StateUniversity kits are available at most garden centers or for $9 through this website: http://www.aasl.psu.edu/SSFT.HTM.

The ideal pH for blueberries is down around4.5 to 5 – very acidic. Sulfur will get you back down there if the pH has beenmigrating upward. Holly-tone is a good, acidifying fertilizer, but it's onlymildly acidifying.

The soil test also will tell you if you'relacking any key nutrients or if the mix is out of whack. The report willrecommend what product to add in what amounts, specific to blueberries.

One other thing... I've found that the mostcommon reason for tartness complaints in blueberries is that people harvestthem too soon.

Berries are sweetest when they're fully ripe– almost right before they start to rot. I've seen berries that look nicelycolored but that are still a day or two or three away from being fully ripe.

Not all berries ripen at the same timeeither. So it's possible to do a picking where some of the berries are sweetand some are tart from the same bush at the same time.