At this time of year, some foliage can start turning red or yellow depending on variety and dropping early especially if older foliage lower down the stems.

Many Thanks

The large majority of Vaccinium hybrids (Blueberries) are deciduous and naturally shed their leaves every autumn, the leaves turning various shades of vivid red/orange and yellow before falling.

The plants will also drop their foliage early if under stress (from drought, for instance) although with the long-ish period of cooler weather following a drought many trees and shrubs are already showing their autumn colours down here (though not the Blueberries!) so that's what might be going on with yours at the moment.

Many thanks for that,very helpful!