I only grow blueberries in containers, but here's what my Sunset book on "How To Grow Fruits, nuts & Berries" has to say about Brambleberries (blackberries & raspberries):
Blackberries are better adapted to broader range of weather than raspberries, especially to hotter climates.
They fare best in deep, rich well-drained sandy loam soil, pH 5.5 to 6.8 and full sun. Depth & drainage more important than soil texture at surface.
Susceptible to verticillium wilt. So, don't
plant them where
potatoes, tomatoes, eggplants,&
peppers have grown within the previous 2 years or within 500 feet of older brambles.
Bears fruits in second year. Life span 5 to 30 years.
Watering: Better to underwater than to overwater because they are susceptible to root rot. In dry area, water weekly or less often allowing top 2 inches of soil has dried out (between watering).
Fertilizing: Manure or commercial type fertilizer specifically for berries. For younger
plant use 5-10-5 (N-P-K), for older
plants, 10-10-10 or 5-10-10. Follow label instructions for correct application.
Pollination: Self pollinating. So, probably you should not worry about cross pollination. But, you know what, I don't think the bees really care if you
plant them closer or far apart, they'll find ways to visit both. Planting them away from each other will give each room to grow.
Pests & Diseases: Watch out for Aphids, borers, leaf and cane spot, mites, strawberry root weevil, root rots.