Does anyone know which should be done first? I would think you’d want to dethatch your yard first, and then aerate. But, I haven’t been able to find anything that indicates one should be done before the other.
Perhaps it doesn’t matter. But if it does, I’d appreciate any info on it. My yard needs both, and I’d like to do it correctly.
Be careful dethatching in the spring, since that’s when your new grass is coming up, or its too wet. I don’t think it’s the end of the world, but on average in the fall during a dry period is better. De thatching can be done well or poorly, and done poorly it can rip up tender roots. And of course you want a little thatch–1/2 inch or so.
My guys dethatch first and then core aerate when I order both at the same time. I personally doubt there is much danger of sequencing one over the other, but dethatching last would mean adding a pretty big volume of cores to the thatch when they rake it all up.
Core aeration leaves the cores scattered on the grass and are an aesthetic problem. With regular watering they will break up after 2 or 3 weeks. Dethatching will break them up immediately.
In this part of the world we do our dethatching (aka power raking) in Spring. If you wait until the lawn gets really green more damage than good will be be done. You’ll tear up the new growth as well as tearing out the old dead grass.