Yes, TOPIARIES is a Scrabble word!

Letter values in Scrabble US: T 1, O 1, P 3, I 1, A 1, R 1, I 1, E 1, S 1.

Is it a valid word?

TOPIARIES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a garden having shrubs clipped or trimmed into decorative shapes especially of animals
making decorative shapes by trimming shrubs or trees