Panicle hydrangeas are far less fussy about where they will grow than some other types. Think of them like any other shrub in your landscape–undemanding and easy to grow.
In USDA Zones 3-7, Fire Light hydrangea will be the most vigorous and produce the most flowers if it is grown in full sun. In warmer zones, some afternoon shade is preferable. No matter where you live, your hydrangea will benefit from a 2-3 inch layer of mulch to keep the roots cool and moist.
Panicle hydrangeas will tolerate most soil types as long as they are well-drained. This plant doesn’t grow well in soggy soil so if that sounds like yours, you may need to improve the drainage before planting. While many types of hydrangeas prefer acidic soil (pH less than 7.0), panicle hydrangeas can live in acidic and neutral (pH 7.0) soils.
When planting, dig the hole about twice as wide but just as deep as the container it is growing in. If the roots are densely circled around when you take the plant out of the pot, loosen them up a bit to break the “root memory”. This will encourage them to grow outward instead of continuing to grow in a circular pattern.
Set the plant in the hole, making sure that the top of the rootball is level with the top of the surrounding soil. Then backfill the hole with the soil you dug out. Press it down with your hand firmly to eliminate any big air pockets around the roots.
Lastly, water the plant again to help the soil settle. Spread some mulch around the base of the plant, taking care to keep it from touching the plant’s stems. The mulch will help to retain soil moisture and protect the roots during winter.