Where are you located? Tiger grass is a semi-tropical warm season perennial grass - grows vigorously during the hot summer months but is semi- to fully dormant in fall and cooler weather. I would not expect it to produce any significant growth at this time of year.

In many cases it is not advised to plant warm season OG's late in the season or into fall as the roots will not extend or develop over winter and you risk the plant rotting in the cool, wet soils.

Sorry i forgot to mention that i live in Sydney, Australia. It has been very warm and dry (no rain in about 6-8 weeks) of late and i have been watering the tiger grass about 5 evenings a week. Is that too much?

Since you are in late spring /early summer it should establish easily. It is far better to water deeply less often, that way the roots will reach down into the soil. Give it another deep soaking only as needed. Use a stick or your finger to feel the soil moisture approximately 3 inches down. If it is dry water again.