Racing at Great Yarmouth has been delayed until 30 August following the work to the course's surface.
The developers for the course, which has been closed since September 2014, released a statement in June that they were hopeful of reopening on 23 July.
But in conjunction with parties including the British Horseracing Authority, they have decided to leave the renovated track for another month.
That means there will be six 2015 fixtures at Great Yarmouth.
Jon Pullin, racing operations director of developers Arena Racing Company, said: "We have always said we are committed to ensuring each of our racecourses provides the best possible conditions for horses to race on, be that a synthetic racing surface or turf.
"While we are keen to recommence racing at Great Yarmouth we can only do so when we are confident that the racing surface is absolutely safe for horses and jockeys and will withstand the remainder of the 2015 programme.
"We can now be confident that an extra month of growth will ensure the track will be ready for 30 August."