hello It literally means "el cesped es mas verde al otro lado de la cerca " I understand with that sentence that you will never be satisfied with what you already have, and you will always desire what your neighbor have. So if I am correct with my assumption I will give you some phrases that convey the same meaning in spanish. I am colombian so maybe other spanish speakers use other phrases: " Sé feliz con lo que tienes " "nadie está contento con su suerte " "Las manzanas siempre parecen mejores en el huerto del vecino " "uno siempre quiere lo que no tiene " " gusta lo ajeno, más por ajeno que por bueno " There are many more in fact people don't usually use proverbs like this or maybe they don't say it directly very often, sometimes they just compare what they have versus the other have. I hope it helps.

Thanks Diego.  That's very helpful :)

Esa misa pero en castellano.