Tony,
Don’t have the complete list, but if you reach out Adam Russell I am positive that he can tell you every location of iron cutter in the world. It’s only been around since the last round of NTEP trials so it still fairly new. It was an experimental variety from OK St. and didn’t even a name until 2018 I believe.
Thank-you kindly John. You are correct on the name & timing. IronCutter is the newest commercial bermuda release, and it shows extreme cold-tolerance while also performing very well in droughty, arid places like Phoenix and humid, tropical locales like South FL.. Being so new, we are just getting up enough acreage at US sod farms nation-wide to be able to support full conversions for entire courses. That will happen next year. Tahoma is nearly 3 years older for reference, but certainly an elite grass like IronCutter.
IronCutter has survived -13 degrees and 350+ hours sub-freezing with 0% winterkill in February 2021 in Oklahoma. We've just wrapped IronCutter's first season as the northernmost bermuda athletic field in the country at Northwestern University in Evanston, IL (Ryan Field), and after 2 winters of testing it was chosen as the first planned bermuda planting in Central Park NYC's 160+ year history (besting T31 in tests). Both places are ecstatic with performance.
To steer this back to architecture, we've been fortunate enough to be planted at a number of cool, historic courses in the DMV area up to Philadelphia that are investigating whether to convert from older bentgrass. Most start with a range tee, then convert short game areas, then on-course tees and surrounds until a decision is made on full conversion. I predict 20+ courses in that corridor will convert fairways in the next few years to T31 or IronCutter, mainly because memberships are getting older and it's much easier to get bermuda to bounce for the duration of a playing season rather than bentgrass. That keeps the classic contours playing as they should, and grass heights can be adjusted much quicker to respond to stresses of each season. As a researcher and lover of both grasses as playing surfaces, bermuda wins over bent right now because it can adapt better to cold than bent to heat with less inputs. Many places in the US Mid-Atlantic (and even up into the Northeast) have been hotter for long stretches of summer that last 3-5 years than the Southeast US.
Our goal as researchers and breeders of grasses is to make them play exactly as each sport intends with zero inputs. We're not even close to achieving that, but many species are making great strides. We've got bluegrass that can survive well into the Southeast, Bermuda & Zoysia pushing into CT & the PNW, and heat-tolerant bentgrass is pushing back into the lower transition zone against ultra-dwarf bermuda. Very soon, an improved Poa annua seed will release. Great choices for golf architects keen to make courses play a certain way.
If anyone has further questions or wants references, message me. I'll recede into the background now.