Hi Joe,
Firstly welcome to the ODK Forum and I'm glad you're enjoying it.
Now,
The only reason I suggested every second year is many people find it an arduous task to do it every year, thus every second year would be the furthest I'd leave it, 3 years is just way too much. My neighbour across the road hasn't done his for 5 years and he has 125mm of built up thatch and is wondering why his lawn won't green up, basically it's strangling itself.
Yes you are correct, if you are using a grooming reel every so often this will reduce the amount scarifying that will need to be done, but remember scarifying also thins out the root system as it goes subsurface while grooming doesn't.
I'm really glad that you benefited from this thread as we don't have a lawn maintenance sub-forum at this present stage, but we're working on that. The more support we get the more likely it is to happen.
BTW I haven't added the final full coverage shots as the lawn has just gone into dormant mode and as such I'll do those at the beginning of the next season while the lawn jumps into super green mode.
Cheers,
BB.
