Brynk wrote:

Thanks Dwight
I wasn't sure how tilling wet could "damage" soil structure
I guess it could temporarily clump the soil, but I don't think that would be
classified as "damage"

There have been seasons when continual rain and my tardy soil prep resulted
in till wet or delay planting.

Working with wet soil (soil that is close to its water saturation level),
whether using a tiller or working by hand with with regular garden tools, leads
to compaction or the loss of pore space between soil particles. This reduces the
amount of oxygen in the soil and complicates drainage as well as making the soil
environment less hospitable to microorganisms, resulting in poor plant growth.
That is why it is recommended that one not work (or even walk on or allow
livestock to graze on) wet soils.

There are scores of articles addressing this issue if one does a simple search
on google - it is a pretty widely recognized phenomenon.

pam - gardengal