There is a latent period when they sit for a few weeks to develop internally before they ripen. If they look otherwise normal and healthy, are just green, that is probably all that is happening.

I'm afraid that's not what's happening. The berries are still very small and not growing. They don't look normal to me. My neighbor has blackberries that blossomed and formed berries at the same time as mine, but his berries have grown and developed, and mine have stayed the same. They just stopped growing.

Your post doesn't contain a lot of context to draw from in diagnosing what went wrong, but in general terms my advice would be not to transplant such an established blackberry.

Blackberries are amongst the very easiest of plants to propagate and come into production relatively quickly for fruit.

In order to make new plants simply let the tips of canes arch back down to the ground and make contact. From there the tips will root and you will have a cane that is rooted on both ends. Snip it closer to the tip that rooted after it is established and plant it where you like.

Even better you can add a little mound of dirt or weight it down to help. Or root the tip into a pot. If untended blackberries will spread quite a bit by tiprooting on their own with no help from anybody.

Carolyn,

Did your blackberry plant make normal fruit in the past?

You transplanted a 5-year old blackberry plant in spring of 2011. I assume the fruit was normal in the summer of 2011?

Has your berry plant grown any new canes this year? It must have grown new canes in 2011 to be blooming in 2012.

Does your foliage look normal?

It is uncommon, but some blackberry canes produce only tiny berries after some years of normal fruit. Still, the berries should turn black eventually, but will be of poor quality.

If you dig up floricane in spring it will not reroot this year to feed berries reason for small berries. You done very well to have small berries this year and floricane not die. Next year plant be back with larger berries 2014 production be normal.

Sounds like a bad site or different soil nutrients to me.

Sounds like your plant ran out of food. Fertilize with a good organic fertilizer and hopefully some of the berries will mature if its not too late.

I really don't know where the myth came from that you have to grow new canes to produce berries. I've had the same floricanes for 5 years and they are always loaded with berries.

Oh, and by the way, my Triple Crown Blackberry is in a container.

One more question: Should I cut the bush back this year, or next spring? It is now about 5' wide and 4' tall. I've given up on the berries for this year and hope, as you said, Preston, for better luck next year. I will also use plenty of organic fertilizer.

I didn't get a chance to follow up on this when I posted my initial question, but I want to add my deepest thanks to all of you who responded. I haven't been in the forum before.

Friend Carolyn