I'm 50+ making a career change to HRM - am considering going to culinary school first then HRM school. Is there a need for the culinary school knowledge on the management side of the restaurant business?

Absolutely!
In order to make sound judgements regarding payroll, food costs, menu pricing etc, you should have at least a fundemental knowledge of back of the house operations.
You don't have to go to a pure culinary school, but a least a mangement school that will teach you culinary basics.
In addition to learning the basics culinary principals, schooling will teach you product identification, recieveing, inventory and cost controls.
A apprentice type program would benefit you as well.
Good Luck!

Absolutely not!
I firmly believe that schools (culinary or management) teach only theory, whereas experience teaches you practical applications of that theory. It's like the difference between being a physicist and being an engineer.

You said you're over 50, so working your way up through the restaurant ranks might not be terribly practical. But. . .why not find a restaurant that will let you move from position to position as you learn the relevant theory in your classroom work? For example, you could work as a steward (or shadow a professional steward) when learning about food cost controls. There's a terrible labor shortage in this business, particularly in my area, so finding a restaurant or hotel willing to work with you shouldn't be a problem. You might even be able to get internship credit!

Best of luck to you.

For the record, I am the General Manager of a fine-dining establishment. My degree is in Engineering as opposed to HR Management. I started off as a cocktail waitress and have, over the course of 10 years, successfully worked every position in the Front-of-the-House and Back-of-the-House. I would never hire a manager who had no practical experience.

There are a lot of amazingly talented people working in the business. Work with them and learn from them. . .it's the best education you'll ever get!

I believe a person occoupying a management position should know pairing combinations i.e. wine and food. They should also understand regional cooking and wines. They shouldn't have to know how it's prepared though. I am speaking strictly about FOH management. I make this statement because my GM told me I couldn't serve Chianti at a Tuscan wine dinner. I had to laugh and he is no longer with us.

I think it would be an invaluable asset. If you are going to be a FOH mgr., you should know what is happening in the HEART of the restaurant!!