Modifying the soil profile at a depth beyond what traditional core aeration can achieve typically requires working with a contract aeration company because of the need for specialized equipment. However, if only a few isolated areas require attention, deep rootzone modification can be performed in-house with a few simple tools.
All one needs is a sheet of plywood, a drill, an auger-style bit, dry sand and a funnel. The first step is converting the plywood into a template by drilling holes at the desired spacing and width, making sure to use a bit that is slightly larger than what will be used to drill into the putting green profile. Once the template is completed, it should be placed over the problematic area that requires soil modification and holes should be drilled into the putting green itself. During drilling, the material that is removed should end up on the plywood. After all the holes have been drilled, discard the unwanted material into a utility vehicle and check the holes to make sure they are clean. Then, fill each hole with dry sand using the funnel. It is important to use dry sand because it will flow into the holes much easier than damp sand. Some light brushing may be necessary if excess sand remains on the putting surface.
While this DIY project is labor intensive, it is very effective at modifying the soil profile. This is also a great way to evaluate the impact of deep rootzone modification to determine if it is worth hiring a contract aeration company to complete all the putting greens.