How to distinguish mature grass?

[Siane]

I am planning to grow oat grass in my home for Russian but I heard that mature grass is not god due to high protein.

I would like to know how to distinguish mature grass.

Lenght? Or growing period?

 

[Littleredfootbigredheart]

Hello and welcome to the forum!

Russians aren’t a grass eating species, so unless it’s to plant as a flooring in their outdoor space, I wouldn’t worry about it

Don’t suppose you’d mind sharing a photo of your full set up and tortoise? It’s lovely to see with new members!

 

[The_Four_Toed_Edward]

As @Littleredfootbigredheart mentioned, Russians aren't grass eaters but there is plenty of other edibles you could plant instead.