"grows less" is correct and usable in written English.
It is used when the amount or quantity of something is decreasing. For example, "As the days get shorter, the amount of sunlight each day grows less."
Davis here grows less abstract, more human.
The rest of the world, seeking to emulate French achievements, grows less prejudiced by the year.
The Buddha, Mr. Dematerialize, grows less and less visible the higher he rises toward heaven.
India is facing an energy shortage even if its economy grows less than previously expected.
So Cole's search for him grows less credible and less urgent.
Deglobalisation is the alternate state where trade grows less than GDP.
Despite Selig's staunch stance, contraction for the 2002 season grows less likely with each passing day.
" 'As one lamp lights another, nor grows less, so nobleness enkindleth nobleness,' " he read aloud.
Quarterbacks By the day, the situation grows less and less sustainable.
When Europe's economies shrink, Italy's shrinks more; when they grow, it grows less.
Blackthorn usually grows less than 3.6 metres (12 feet) tall and has numerous small deciduous leaves.
