The poor condition of the tree – located in a private garden – makes it a significant hazard for overhead electricity lines in the area, as well as a potential danger to those travelling on the A77 itself.
To allow for the tree’s safe removal and to minimise traffic disruption, the A77 will be closed between 8am and 4pm on May 2.
Signposted diversions will be necessary from Alloway to Turnberry, with local access maintained.
Angus Campbell, SP Energy Networks’ District General Manager for Ayrshire, said: “We’re sorry for any inconvenience or disruption this necessary road closure may cause, but we need to take action now to make this location safe – and my thanks to the concerned locals who brought this matter to our attention.
“Left to its own devices, this tree could bring down the power lines or fall on to the busy road.
"This would not only create a significant danger for local people but would also interrupt power supplies.
"We want to avoid both those scenarios, which is why we are stepping in and getting to work on doing what’s needed.
“We would urge those who are planning to travel on the A77 on Sunday to allow more time for their journeys and thank them in advance for their patience and understanding while we carry out these necessary works.”