Blackberry won't grow in miracle gro pot?

[geronimo]

I have a blackberry vine planted in a 5 gal pot, the two large branches are (although much is dead wood now) about 18 in tall. The soil is miracle gro. I measured the ph of this stuff, and it is a bit acidic. The pot is well drained, and I put lots of rocks at the bottom to keep the soil from going out the large holes. It is in full sun, and the days lately have been in 70s and 80s. There are only green leaves left at the bottom of the plant now, it is dying from the top down. I did not damage the root ball when planted, it had a big healthy root ball. Why isn't it growing? I am in the northern edge of zone 10. Black berry vines grow wild here. But this one was purchased at supermarket. I keep it just slightly moist. Any ideas?

[Hal]

All blackberry aren't the same. You may have purchased a vine that grows well in another climate.

You should be able to find a wild one and get a piece of root. They usually taste much better than the one's for sale anyway. If you want the best tasting, get a wild dewberry. Like a blackberry, only grows along the top of the grass and low weeds near the swamps. You will recognize them by the vine sliding across your boots or the thorns cutting into your leg. I'm assuming they grow where you are they grow in South Georgia.

Regards,

Hal