I am a bit north of you (southwest OR) and relatively new to growing potatoes. In 2010 I planted early on March 20 and I felt that the plants languished for a while before picking up even though it seemed like spring to me- there was no frost damage to the plants and the harvest was good. This past year I planted on April 24 (right about my average last frost date) and had quite a bit of success - very nice plants that grew quickly and produced well.

I will definitely plant my potatoes this year after mid April to mid May. The weather here in late spring and early summer can vary quite a bit (it always annoys me to see weather people talk about rainfall amounts or temperature and say how low we are on the month or how high we were for the week, seemingly not understanding what an "average" is).

I think you can do well with planting store bought potatoes, but if you can find a nursery or farm store that sells certified seed potatoes you will know you are off to the best start possible, and the price difference for your planting would not be much.

From my reading - an oversimplification of the problem with using non certified seed potatoes is that potato viruses which seem to be ubiquitous build up in the plants and tubers and in time depending on growing conditions and the number of generations the yield will be reduced significantly. To reduce disease potatoes are periodically cultured from tissue from a certain point on the plant. The resulting plants are eventually grown into plants that are grown for seed potatoes until they fall out of specifications - seed potatoes are not certified to be free of disease, but to be within certain tolerances. Seed potatoes are grown where practices and climactic conditions limit the accumulation of relevant disease in the soil - which is not necessarily where and how your store bought potatoes were grown.

Hope this helps. Best of luck!

I was told/read that there are two types of white potatoes.
That one will only grow tubers on the bottom, no matter how deep you plant it in a container.
The other type will grow tubers along the buried stem.
I searched for prove of this & have yet to find it.
I will post a link if I find it.
In the mean time here is a link on ways to plant the potatoes & it has youtube links also.

Here is a link that might be useful: potatoes in bags,drums & tires

Jolj, I seem to remember coming across that info at Irish Eyes Garden Seeds, but their site is down/under reconstruction. I did find a mention of it at Sinfonian's blog. The link follows. Cheers!

Here is a link that might be useful: Sinfonian's sq ft garden blog (old)

I won't try and offer timing advice, but a bit of a warning...
My potatoes were all originally certfied. I never managed to get out all the tiny ones, but they were so healthy I thought I'd just leave them in as basically perennials. They prceeded to romp happily through the berry patch, under the fruit trees, etc, etc.
All fine, except right now,. I have late blight. Easy enough to pull the tomatoes, a different prospect trying to find a million random potatoes. I'm basically hoping that I cut most of the haulms in time and most of the tubers are ok.
When I plant potatoes again, there'll be no free-ranging allowed and I'll be very careful to dig out every little spud.

Thanks for the info, guys! I'll go by Baker Creek after my April chiro appt. I'm sure they'll have some seed potatoes.
I'll be planting them in some sort of barrel or contained area, so hopefully no taters running rampant!
I'm looking forward to it! Nancy

I try to plant my potatoes the last week of February, or the first two weeks of March. Yes you can use any potato for a seed potato, just let it age some, and plant sections that have at least one bud.