Generally both are done in the fall... dethatching a lawn should only be
done every 5 years or so. If it has *never* been done to the lawn (or it's
been a great number of years), you can expect to pull up an enormous amount
of thatch... if you do it in the spring, you really should overseed
immediately as the newly opened space will quickly trigger all sorts of weed
seed germination (weed seeds that have been lying dormant, sometimes for
years).

Core aeration is also typically a fall task. I like to core aerate every
year, followed immediately by fall feeding and any soil amendments I might
be putting down.

Dave

"lbbs" wrote in message
...
Does it matter on the order you do it. Also, what time of the year to
do
it?