A deep root watering and stabilization assembly and method for supporting, irrigating, and fertilizing plantings, such as trees, shrubs, or root balls is described herein. The assembly can include a harness disposed around the planting and a perforated tube adapted to receive water and nutrients from above the surface and pass the water and nutrients to the roots or root ball. The assembly can include an attachment assembly with adjustable engagement locations and a fastener affixed to the attachment assembly. The fastener can be structured to tighten or loosen a first connector as it engages one of a plurality of positions between the harness and the perforated tube.
