Next you need to compact the sub base material. If you do not compact the sub base material properly it will eventually settle in a way that will cause irregularities in the surface of your putting green. These irregularities adversely affect the roll of your ball when putting. The plate compactor can be rented from any local rental facility. With your garden hose and spray nozzle wet the sub base, but does not saturate it.

Now compact the sub base. You will want to compact the sub base several times the length and width of the area to insure good solid compaction.

If there are any small bumps, ridges, or irregular dips remaining, smooth them out with your rack or shovel. Use a 2 x 4 to screed or level the base material. You may notice low spots or dips on your base. Chances are that you have a low spot on the sub base that needs to be filled. Your main goal is to keep the surface consistently flat, smooth and solid.

Adding an undulation or contour is very easy. Simple add additional base material to that area and shape it with your rake until you have the desired contour and undulation. Then compact that area with your plate compactor.

Understand a 1 inch rise over 1 to 2 feet will add a lot of contour once the putting green is added.

Understand that the putting green turf is going to fit like a glove to the surface you will put it on. If you add too much slope to your sub base material the ball will roll very fast and may roll off your green.

A good basic guideline is for every 10 to 12 feet in the length of your sub base you will drop the slope 1 inch.

The best way to determine whether you have enough or too much slope or contour is after you have completely compacted the sub base material is take a golf ball and putter and putt on the sub base.

The ball will break the same on the sub base as it will when you install the putting green. Your sub base should be a minimum depth of 4 inches when compaction is complete.

Make sure the sub base is the way you want it. If you want to add or take away extra slopes or contours now is the time to do it. If you make any changes to the sub base then you must re-compact the sub base after the changes are made. Once the putting green and the infill is added it will be difficult to adjust the contours of the sub base.