Hair salons in Germany have finally opened their doors after weeks of lockdown -- but Germans desperate to fix their overgrown locks must make appointments and even fill out questionnaires, as hairdressers deal with huge demand.

Sites have been allowed to open from Monday after six weeks of closure, as Germany starts to creep out of its economic paralysis.

But hair salons are subject to strict restrictions -- cuts are by appointment only, and social distancing requirements have forced them to operate well below capacity.

"Most of the customers have two centimeters of roots showing," celebrity hairdresser Udo Walz told CNN.

"Some of them tried to cut their hair themselves or cover up the color, but that usually went wrong.

"Walz, who has styled hair for Marlene Dietrich, Nancy Reagan and Gwyneth Paltrow, said he has been giving advice over the phone to customers.

"Everyone is wearing masks, the customers, the hairdressers," Walz added of the scene in his salon on Monday.Like other hairdressers in Germany, he is required to leave every other chair empty.

Hairdressers are required to only cut dry hair and disinfect surfaces regularly.

In Berlin, customers are being asked to fill out forms with personal information before they can secure a spot in the hairdresser's chair.

The paper asks for a customer's name, address, signature, and the time they entered and left the salon.

Anne Bruemmer, the owner of Salon Heidi, a smaller hairdressing salon in Hamburg, Germany, told CNN they are "overrun."

Bruemmer said that, although clients have to book appointments and the salon has planned the reopening meticulously, they are now booked out two weeks in advance.

The loosening of restrictions is part of the first phase of Germany's tentative reopening of society.

Violating safety measures puts hairdressers at risk of a €500 ($547) fine, Bruemmer said.

Some schoolchildren will start returning to lessons this week, but Chancellor Angela Merkel will hold talks with regional leaders on Wednesday about more businesses and services opening nationwide.

Germany has recorded more than 165,000 coronavirus cases and 6,866 deaths, but has been spared an outbreak on the scale as those seen in nearby France, Italy and Spain.