YA Sci-fi. A group of kids do a series of play simulations of being on a different planet. They go into a simulation like normal one day and realize they're actually on the planet. They have to survive. Rea in 1990's.

[Sophie]

I read this in the 90's. It was a sci-fi dystopian YA novel. A group of kids think they're going into these repeated sessions of hyper-realistic simulations just to play, as an activity. The simulations always place them on what they think is an imaginary planet that they're allowed to explore. But one day they "wake up" in the simulation and realize it's real. They figure out that their caretakers sent them to the planet to populate it.

If I remember correctly, the Earth was on its way out, and so adults decided the best way to continue the human race is to send groups of children to various known planets to colonize them. The simulations were actually trainings so that they would be familiar with the worlds when they got there, and each group of children was trained for a different planet. They were put into stasis while they travelled to the planet and didn't know.

I seem to remember there was something on the new planet that looked like grass, but was actually sharp enough to cut, like glass.

[Rainbowheart]

I should know this!

Your description kinda reminds me of Galax-Arena and Invitation to the Game, but not sure the details are a match.

Sharp grass that cuts feet is also present in The Green Book .

[Sophie]

Invitation to the Game seems very close! I think I read The Green Book in school around the same time, so it’s possible I am conflating them!

[bookel]

Invitation to the game by Monica Hughes was my first thought.

[Emily]

Children in a simulation that's not really a simulation also sounds like 'Ender's Game's, though it's a battle game rather populating a planet.

[Bren fall in love with the sea.]

Invitation to the Game