Supposedly, seed potatoes are known to be free of diseases. Who knows if
it's true? The other issue might be that they'll be varieties you don't
often see in stores, some of which are quite interesting and tasty.

As far as when to plant, go to google and search using these words:
oregon cooperative extension

Do you know what that organization is?


Oregon State University Cooperative Extension publishes a planting calendar
for the local area, but they don't seperate the different areas of the
valley. Last frost dates in the valley vary by as much as 3-4 weeks, as do
planting times, depending on where in the valley you are. Their calendar is
also very conservative - they don't want anyone to follow their advice and
then have crops freeze/fail. I went ahead and put a bunch of onions and
potatoes in the ground, since we have had a few dry weeks, and it's not
likely to be this dry again for another 3-4 months (once it starts to rain
again, it won't stop until June). I put in about 4 feet of daikon just to
see if they will grow. I have little to loose if they don't, and since
daikon is very sensitive to warm weather, they just might do good if planted
early.