The worm farms are good for making compost and soil conditioners,however the worms themselves are not suitable for garden soil as they are unlikely to survive for long.You can also grow worms for fishing.
I have a worm farm as well as a compost bin.The worms do well in both,but the compost bin is far less fuss.They also work well in accelerating the composting process.
Surprised the manure hasn't attracted garden worms.Perhaps it would help if you dug it into the soil.Adding compost too, would have to help,along with worms from anywhere else in the garden.If no improvement I'd say that the manure is to blame and came from animals that had been drenched prior to their manure being collected for sale ie anthelmintic drugs are to kill intestinal worms,but also deadly to earthworms.
