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Someone asked me at the Northern Green Expo if the temperature-based growth potential (GP) and temperature-based growing degree days (GDD) are comparable. They sort of are, with a couple of exceptions.

I received this inquiry by email: When looking at water quantity for a new golf course, you have to determine how much water is needed obviously so what I want to know is

I taught five seminars at the Northern Green Expo in 2016. The (New) Fundamentals of Turfgrass Nutrition Nutrient Use by the Grass and Nutrient Supply by the Soil Calculating the Fertilizer Requirement for any Turfgrass, Anywhere

This chart ( download at full size ) shows the average photosynthetic photon flux density (PPFD) for each hour of 2015 at Tokyo. The daily light integral (DLI) is the number written in black at the top right corner of each facet in this chart.

I made a map of all the flights I took in 2015.1 After seeing the map, I scrolled through my photos from these places. It was an extraordinary year for studying grass around the world.

After I wrote about no problem DLI levels, Brandon Horvath asked if I could get DLI for some cities in Tennessee. For a description of how I made the calculations, see Estimating daily light integral (DLI) in 4 Tennessee cities.

For warm-season grasses on putting greens, I propose a no-problem DLI of 40 for bermudagrass, 30 for seashore paspalum, and 20 for zoysia. Above that, and there is enough photosynthetically active radiation (PAR) to easily manage the species. Below that, and it won’t be no problem anymore.

One of the best places to study tropical grasses in Southeast Asia is at the Suanluang Rama IX Public Park in Bangkok’s Prawet District. The two primary species on lawns at Suanluang Rama IX are tropical carpetgrass (Axonopus compressus) in shaded areas and manilagrass (Zoysia matrella) in open areas.

In January 2016 at the Northern Green Expo in Minnesota, I got to talk about light, water, temperature, and nitrogen. Those are the factors that influence growth, and getting the growth rate right is what greenkeeping is all about.

When I saw this photo captioned “a little potassium replenishment being applied,” I asked “replenishment from what loss?” As I found out, the potassium (K) was being applied after a heavy rain event.