Any advice for improving blackberry bushes?

I don't know if they are wild or not, but last summer, we discovered we've moved into blackberry heaven. Out back of our biggest barn is a huge line of blackberry bushes all along the back wall. Last year I picked several quarts, ate some and made some into blackberry jam (came out real thick like pate, but whatever, it was good).
The only thing about them is, some of them aren't very sweet, and they don't get too much bigger than the wild blackberries, so I was wondering what I might do to improve them- fertilizer, pruning, etc...
We don't water them, because there are too damn many of them (that and my cheap-ass stepdad won't fix the pipe for the hose), but if I could clip them or throw some stuff on them once or twice, that would be okay.
Any advice for a novice would be nice.

 

My hubby does a lot of landscaping,and he said to tell you to dig them up and trash them,he said its like growing pineapples in Kansas not the right climate...He was just kidding you...LOL
Just keep em pruned back,if you could water them somehow,it might make them a little sweeter...
Let me know how it turns out...

 

Hahaha, thanks to you both!
I thought pruning might help... It's definitely a day or three's worth of work, though. Damn theys a lotta blackberries! I should take a pic and post it.
The only thing I can think of for watering is a hose. We'll see how far down I can whittle the old man.

 

We have thornless blackberries and I love them! After a while, some of the canes die ... you're supposed to pull the dead ones and remove them so they don't collect some disease that could be transmitted to the living. So I've done that the past couple of years; the dead canes pull right out from the ground easily and they're gray, whereas the live dormant ones are reddish-brown colored. I throw a load of dead leaves over them in fall, for mulch and fertilizer, and some horse manure.

 

since you aren't going to water, a heavy mulch will help retain the water received.

 

Yeah, I just read up on how to prune them and how to discern the good canes from the canes that won't fruit again, so in the next week or so, I'll be braving the cold and snow to do that... Thinning them out will make them easier to deal with, too.
Damn blizzard coming tomorrow. Can't them temp just go up, like, five degrees? Pretty please??
Blerg, winter blahs! I want to be productive!

 

I have some that have gone ballistic on the edge of my hill. They help with erosion on the slope, so I let my gray water drain there, and don't worry about pruning or watering them. About every three years though I do broadcast some triple 16 over the area. I am considering borrowing a couple of goats for a week and letting them do some pruning/control late this summer.

 

Is that organic?

 

No to the triple 16. But it's an environmentally sound practice. It's readily available, cheap, easily applied, plant response is more immeidate. I don't use it excessively. There will always be trade offs in life.

Use of the goats would definitely be considered organic.

 

Thanks, just wondrin', no worries.