Posted: 20/01/2014 at 23:16
Hi djjjuk, blueberries must have acid soil, so if you aren't sure what you have, get a soil testing kit (which aren't expensive.) They a need a pH value between 4 and 5.5.
If your soil pH is higher than 5.5, they won't grow well and will probably die if it is alkali (ie the pH higher than 7.)
Raspberries do like a slightly acid soil but won't grow well at the low pH levels blueberries need so you can't really grow them together.
The alternative is to grow your blueberries in large containers using special ericaceous (acid) compost and they do well when grown like that. You could probably grow at least 6 large pots of blueberries in that space and plant raspberries in the ground behind the pots so you would get the best of both worlds.