Update: April 1, 2010

I hit the green with some Immunox contact fungicide a couple days ago to hopefully save some spots lost to what appears to be brown patch, a common lawn fungus that turns grass a brown color in a ring/circle shape. Also put down some more starter fertilizer to continue to help the young seedlings to root.I graded the area above and around the green to prepare for more sod.

Update: March 23, 2010

The green is really starting to green up. Reseeded and put some starter fertilizer a week ago to help fill in bare spots.

Bunker Construction

To start, I dug a hole about 6 ft in diameter in the side of the slope. Once all the dirt was excavated, i dug a drainage trench with a T in the lowest point of the bunker to collect water and drain it.

I put a little gravel in the bottom of the trench, then put drainage tile running along the trench. The drainage trenches were then backfilled with more gravel, very similar to the drainage system on the green.

To keep the dirt from coming up, I placed a white geotextile fabric. Sod was then placed around the edges to hold all the soil in place.

Snow

The winter of 2009-2010 was a record snowfall year for the Charlottesville-Albemarle area with over 60 inches of snow. It started on Dec 5 with about 3-4 in of slushy snow which didn't last very long. On December 18 2009, 27 inches of snow fell in a time span of about 27 hours starting Friday afternoon lasting until Saturday evening. The snow lasted until January 18 when the last of the snow melted off the green. Then on January 30th we received another 10 inches followed by 3 more inches February 2nd. Before any of that could melt, 18 more inches fell February 5th and 6th. The final snowfall came on February 9th and 10th, about 3 inches. This snow was both beneficial and harmful to the green. It helped because it acted as an insulator of the green. It did however starve the green of oxygen and sunlight. There was no lack of water, that's for sure. The green really started greening up around mid-March.

First Germination!!

Finally! After12 days of nervously and anxiously waiting for signs of grass, tiny sprouts emerge from the rootzone.

Over the next couple of days more and more sprouts emerge and soon are visible from a distance.

Standing below the green, it looks like a field of tiny green shoots.

Rootzone Layer

The final layer is the rootzone layer, which is about 10-12 inches of a mixture consisting of 90% sand and 10% peat. This is the stuff the grass will actually grow in. For this I ordered 20 yards of USGA spec rootzone material from Luck Stone Specialty Products. This was delivered in a monstrous dump truck.
Now it was time to get the rakes and start spreading this stuff out. Stakes were set out around the perimeter and around the green to ensure the rootzone mix was spread out at a consistent depth. Once all evened out, the rootzone was rolled multiple times and re-graded to even everything out.

Next, starter fertilizer was mixed in the top 1-2 inches of rootzone. Finally, 1.2 lbs of Declaration bentgrass seed was spread out and rolled a final time for seed to soil contact.

Over the next couple of weeks, the green was watered on intervals of 4 times a day for 15 minutes at a time. This did of course change with rain and cooler temperatures meaning less watering.

Drainage

After grading the area, the next step was to install drainage, a key component in any putting green. To build the green to USGA specs, there must be drainage trenches with drain tile and then an additional 4 inches of pea gravel.

18 tons of #8 gravel from Luck Stone. Hauled it all by hand.

Drainage tile going in trenches with gravel back fill. The tile has small slits to collect water and carry it out the bottom of the green. Duct tape is used on all joints to prevent them pulling apart.

Drainage Layer complete with 4 inches of gravel. Note the clean-out pipe for the drainage tile at left of the picture to clear out gunk and dirt.