Let me go into more detail as to how and why an older green can and will remain firmer longer....POA greens will soften much faster over time. If a bentgrass green is planted and the proper culture practices are done (Plant Air, Dry ject, aerify, liquid fertilizer, topdressing, brushing, grooming, verticuting, removal of poa, etc...) older greens will be firmer. Poa is a much more "sticky" grass that CAN retain water longer, partly because it's a bunch type grass, which makes it much more difficult for water to get through the soil, making is softer. It is okay to have a 1/2 inch layer of thatch.
I also recommend using much more of liquid fertilizer than a granular because a graular usually has much more Nitrogen in it, which will allow for the more Organic matter to form, which leads to a denser thatch layer.
Tony Nysse
Asst. Supt.
Long Cove Club
HHI, SC