A group of 12 of us golfers used to hit MB for golf in April every year. Smaller crowds. Many of the courses were being over seeded at that time. I asked one of the pros and he blamed it on the sandy, salty soil in the area. They used to over seed in the fall with a tougher, drought tolerant Bermuda grass for the winter months, and re-seed in the spring with a finer blade grass for the prime golf season. Maybe you caught them in the crossover period. Every time I've been at Willow Tree, its been beautiful. You can always ask them. We played a course down there one year where they completely lost all their bent grass greens. We had to putt on sand.
Like Kermit the Frog says, "It isn't easy being green."