Trellis for blackberries

[mater]

My blackberries that I planted last year only produced about a cup of berries. This year they are loaded.  Most are still green and they are beginning to turn red.

I thought I would share what I did for a trellis.  I would have included pics but my daughter has my camera (as usual).  Anyway, I'll try to describe it.  Last year I sat three 8 ft 4x4's in the ground spaced about ten feet apart with about 6 ft out of the ground.  I didn't use cement to set them.  I used three strands of heavy plastic coated clothes line wire and had the strands running about 18" from the ground, 3 ft. and the highest at 5 ft.  I bought some large eye bolts and drilled the two end 4x4's to accept the eye bolts and the middle post I just put large eye screws at the same heights on both sides.  My reasoning was that as the wires became slack I could just tighten the eye bolts on the end posts and keep the wires taut.  This worked great until I began noticing the end posts beginning to lean in a little from the tension.  Setting them in cement would have prevented this.  So, this year I attached 10 ft long 2x4's across the tops of the 4x4's to prevent this.  Now I can tighten the wires as tight as I want and it's working great.

[Pjames]

Mater I use a similar trelis on my blackberry trellis. Mine is much smaller, only 10 ft long. I used landscape timber for my uprights. My crossbeam across the top is a cheap 1X3 with a 1X2 under it on edge. Cross section would look like a T. It is in its 4th season with no sign of bowing.

I used the T configuration because you can use some cheap material and get great strength. When I had my pet store one of the manufacturers would sell wood aquarium stands for large tanks, well over 55 gallons. They used relatively lightweight wood but it held the massive weight of those tanks easily. The trick was the T for downward force and wood around the frame to prevent any twist that would let the stand move off center.