DIY Backyard Putting Green: Base, Turf and Real Costs

Everyone focuses on the turf. The base is what decides whether a putt rolls true, and it is where every disappointing home green goes wrong.

The build

1. Set out and excavate

• Mark the shape with a hose or spray line. Curves putt more interestingly than rectangles
• Excavate four to six inches, more on clay
• Keep a slight fall of about one percent across the whole green for drainage
• Barrow the spoil out now. Excavated soil bulks up by about a quarter and it is the hidden cost of the job

2. Membrane and base stone

• Weed membrane on the subgrade, under the stone — not between stone and turf
• Crushed stone, angular with fines, in two lifts of two to three inches
• Compact each lift with a plate compactor. One thick lift does not compact through, and that is what produces hollows in year two
• Check level as you go, not at the end

3. The screed layer

This is the layer that makes it putt.

• Half an inch of stone dust or decomposed granite
• Screed it with a board run over rails, as you would a sand bed for paving
• Compact lightly, then re-check with a long level in several directions
• Any contour you want in the green goes in here, gently — a putting green with a hump is a feature, with a dip is a fault

4. Turf, cups and infill

1. Roll the turf out and let it relax in the sun for a few hours before cutting
2. Lay all pieces with the pile running the same way, or the ball speeds up and slows across seams
3. Seam tape and adhesive on joints, pulled tight
4. Cut the cup holes with the cups in place as a template
5. Fix the perimeter with edging or turf nails every few inches
6. Brush in silica sand infill to the manufacturer’s weight, in several passes, brushing between each

Costs, honestly

• Putting turf — usually the largest line, commonly several dollars a square foot
• Base stone and stone dust — bulk delivery, cheap per tonne, expensive to barrow
• Infill sand, cups, flags, edging, seam tape
• Plate compactor hire for a day or two
• Spoil removal, which catches people out

A small three-hole green of a few hundred square feet typically lands in the low thousands done yourself, against several times that installed. Access dominates the number — if a machine cannot reach the garden, the excavation becomes the biggest cost on the list.

Design, briefly

• Three to five holes is plenty for a domestic green
• Curves and lobes give varied putt lengths from one position
• A gentle contour or two makes it worth practising on; a flat rectangle gets boring fast
• A fringe of a different turf around the edge looks right and catches overrun
• Site it where it drains and where you will use it — the far corner of the garden is where these end up unused

Maintenance

• Brush against the pile every few weeks to keep it standing
• Top up infill once or twice a year
• Blow or rake leaves off before they break down into the pile — rotting debris is what grows moss in artificial turf
• Re-level a hollow by lifting that section and re-screeding, which is straightforward if the edges were fixed properly

What goes wrong

• Sand used as the base. It shifts, and the surface dips within a season
• One thick lift of stone, not compacted through
• No screed layer, so the turf follows every lump in the stone
• Landscape turf instead of putting turf
• Seams with the pile running different ways
• Too little infill, so the pile lies flat and the ball wanders