jolly:

Put them in a bowl and add sugar. I haven't heard of anything else other than delaying harvest as long as possible. BTW I like them with a little sugar.

Um, it's called sugar! :-)

Sorry, just being a wiseguy. Please ignore me!

A lot of it has to do with variety and growing conditions. More sun makes them sweeter, as does warmer weather. You may need to try different kinds and see which taste better to you.

Sugar is actually a very good answer. The sweetest fresh blackberries I ever had were little wild fruits growing in deep shade right in Portland (they were not dewberries).

Unfortunately, Triple Crown berry plants are too tender for many regions. If your sole intent is to eat fresh blackberries, you do have a problem. In baked goods involving pounds of berries, use of stevia powder allows the amount of sugar in the recipe to be far less.

For fresh berries, say a 1/2 cup serving, the amount of stevia needed would be tiny. Best to make a mixture of sugar and stevia and reserve it for sprinkling on fresh berries.

We grow 5 varieties Arkansas varieties of thornless blackberries and the Navaho are the sweetest. If they will grow in your area (e.g., same climate as Arkansas and Tennessee), I highly recommend trying to grow a few of these plants. They are quite tasty even when they are still shiney.

Ken Barber
Millbrook AL

What OregonWoodSmoke wrote... They don't sweeten up they loose their shine and become dull.
-Glenn

ok, got it, sugar and sun I can get.

now the mistery is I have about 10ft row of them and half of the row (towards south) is short bushes and have berries, the other half (toward north) is simply 5 ft tall shoots of green thorny thick sticks and practically no berries. Same bed, same conditions, same treatment. Nothing affects them diffrently except the north-to-south direction of the bed. Is that the reason?

...but there is a fine line between dead ripe and over-ripe blackberries (sometimes 12 hours or so), and over-ripe/dead ripe blackberries are hard to rinse without much of the fruit going down the drain, and some people like to rinse their fresh berries before eating. Good blackberries should be more like "melts in your mouth, not in your hand".

jollyrd: It sounds like you are describing two different varieties of berry, or the difference between 1st and 2nd year canes. The compass direction of such a small row should not cause your berry variations. Are all the canes thorny?

I think you should listen to the pro on this one. Barberberryfarm is trying to steer you to a much better solution than adding sugar. The series of berries he speaks of were bred to sweeten while still firm to make shipping them while sweet possible. You can have a firm and sweet berry in the Richmond area, I'm sure. I can grow Navajo here in a Z6 and they only burn when it gets well below zero F. So much better than older varieties IMO.

Mine are Chester thornless, which are very tasty when dead ripe but sour before and bland after. They did overwinter great during this year's very cold winter (when I had lots of winter kill in my red and black raspberries). How will Navajo and Triple Crown do in zones 5 (Delaware County, New York) and 6 (Woodstock, Ulster County, New York)?

I grow Navaho, Apache and Arapahoe varieties and have tried many things over the years to get a sweeter berry. I will start by saying that genetics is the primary influence of "sweetness", meaning that simply some varieties are sweeter than others. But, what I have found is a combination of factors will influence the sweetness of any variety. First is soil, the more organic-rich the soil the better. Clay soil will make a berry hard and tart; conversely a well-drained loomy, highly organic soil will be best. I have discovered that a low pH is essential. I lower the pH by gradually adding sulfur and mixing my native soil with 40% ground pine bark mulch. This adds acidity to the soil as it decomposes. Elevating the plants (a raised bed) will help the soil to drain. During growing season, this type of soil will retain enough moisture to encourage healthy plant growth without being too wet. If blackberry plants are continually wet during ripening season the sweetness will be less than optimal. Finally sunlight is a tremendous influence. Sunlight will amplify the manufacturing of sugar in the berry. I live in south Louisiana which has excellent soil and plenty of sunlight and have found that elevating the beds, allows me to take maximum advantage of the excellent growing conditions, while still giving the canes all the water that they need, but not so much as to cause root rot.

Try Epsom Salt. Makes tomatoes sweters might do the same for berries.

"Try Epsom Salt. Makes tomatoes sweters might do the same for berries."

LOL!! If you believe that, I've got some beautiful swamp land to sell you. 😁