I luv to buy seeds. Burpee catologe is my favorite.
Those seeds from last year are still good but buying new ones are always fun

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I plant my snap peas along a fence. Just a 2X4 inch galvanized fencing that is 4 foot high. Its how I plant my cukes also. You have to help run them up the fence by intwine them.
Plant them early since they dont like heat. Also double up the seeds you are planting since I have never found a pea varity with a good germination rate.
Havent planted them for a couple of years. When I did you could not relay on a good crop, I guess thats the same with all vegies.
I also believe you can do a fall crop but have never tried.