Certified GKH Gardening Expert
This article will help you:https://www.gardeningknowhow.com/edible/herbs/ginger/growing-ginger.htm
Spacing should be at least 8 inches apart for newly planted rhizomes, but realize that they will spread, so you can give them more room to spread by planting them further apart.
I recommend neem oil. This will help control both pests and fungus on the plants.
Ginger will benefit from something a bit higher in phosphorous, as this will help with rhizome development.