The High Hedges (Scotland) Act came into force in April, offering a legal route to resolving conflicts caused when shrubbery grows too large and blocks out light.
The bill was unanimously passed by MSPs but it allowed local authorities to set their own fees for processing applications, which can eventually lead to councils chopping down trees or hedges more than six and a half feet in height, without the permission of the owners, who are then billed for the work.
Research carried out by The Herald has revealed a wide disparity among fees set by local authorities to make applications, ranging from less than £200 in Stirling to £500 in Glasgow.
Figures obtained from Scotland's 32 councils have also suggested a direct link between the amount charged and the number of applications. Almost half of the 28 applications made so far have come in the four areas that charge less than £300, while just three have been made across the seven authorities that charge £400 or more.
SNP MSP Mark McDonald, who brought the bill to Holyrood, called on local authorities to ensure the legislation was accessible.
Dr Colin Watson, who led the calls for the legislation as campaign leader of the group Scothedge, accused some councils of overcharging and said allowing them to set their own rates had proved "a disaster".
Dr Watson, who has since retired from the group, said: The Government left the door open to improve the bill on review and we must hope that they quickly understand the disaster of uncapped local council fees.
"Those who have suffered from this problem and faced a bullying hedge owner - 15% had to call in the police - should not be paying for this at all."
According to Dr Watson, six authorities in England, which has similar legislation, make no charge. In Scotland, Stirling and Inverclyde Councils charge the lowest rate of £192. The two authorities, with a joint population of about 170,000, have had six applications between them compared to the three in the seven councils charging £400 or more, which have a collective population of more than 1.6 million.
Before the law was introduced, campaigners claimed high hedges were causing "misery" in some cases, with as many as 5000 disputes in Scotland. Overgrown shrubbery had been used as a "weapon" in planning disputes between neighbours, it was claimed, and ensuing confrontations were dubbed "hedge rage".
Mr McDonald said authorities should consider introducing discounts for pensioners or low-income families making applications under the law.
A Scottish Government spokeswoman said: "The High Hedges (Scotland) Act 2013 gives local authorities the discretion to charge a fee for administering a high hedge application to cover their own costs and the flexibility to set different fees to take account of different circumstances, as well as the ability to refund fees.
"Making an application is intended to be a last resort measure and certain pre-application requirements must be satisfied to prove that all reasonable steps have been taken by neighbours to resolve the issue before an application will be considered."