Raspberries ...

... can you tell, just by looking at 'em, if they're summer or autumn fruiting?  And how long, on average, do raspberry canes remain productive for? And if they push up new baby plants are these true to type and will they be productive?

The reasons for the questions is I've inherited an under performing raspberry patch.

If the growth is all over the cane they are summer fruiting,if the growth is only at ground level they are probably autumn fruiting.Life span probably 10-12 years.New canes for summer fruiting varieties can be tied in to horizontal wires once existing canes have fruited and been cut down.Autumn canes should be cut to the ground in february.