Blackberry plants

[69bronco]

Looking to set out some blackberry plants this spring. Any firsthand recommendations good or bad on plants? Zone 5, thanks!

[GAB]

In 1977 I put in 40 plants in a 4' x 4' spacing 5 rows wide.
The following year I could not walk through them.
Didn't get enough fruit to get a good taste.
From that experience I would suggest a plant spacing of at least 10'
and a row spacing of at least 20'.
Here in VT we used to have a lot of blackberry patches, but as the cattle population decreased
(today many farms merely yard their animals) so has the blackberry fruit production.
Gerald