Hyrangea on the side of the house

Just planted our first bush on the West side of the house.

Put it in a hole twice the diameter of the pot; soil appears to be ok but full of ash (?).

Here's the write-up on the plant:

Limelight- hardy Hydrangea - Hydrangea paniculata
Exposure: Full sun to partial shade
Season: mid-summer to fall
Hardy to: -40 deg C
Heat zone: 8
Size: H 6 - 8', W 6'

Extraordinary color with exquisite bright lime-green flowers. The flower fades to white adn in fall, matures with hues of pink.

Add nitrogen to the soil to intensify the bright lime-green blooms.

East to maintain and care for. Great cut flowers. Bloom size increases with age.

USPP#12874, CPBR #2319

Brand: PW - Proven Winners