Veteran pea growers can't resist nibbling peas right off the vine. That's because peas, like sweet corn, are at their sugary peak the moment you pick them. From that time on, the sugar starts converting to starch, and sweetness declines.
Tall vining types, which bear over a long season if you keep picking them, need support: a trellis, wire or nylon mesh, or poles. Bush types, which top out at 30 inches and usually don't need support, mature earlier and tend to produce most of their crop at once.
Keep in mind that to reach maturity, peas need three months of growing time before the average date of the first frost in your area. They also need cool soil and air temperatures. In mild-winter areas of California, you can plant peas anytime from August to February. In the desert, wait until October. In the coastal Northwest, sow peas in August for a fall crop. In colder areas, wait until next spring, then plant as soon as the ground can be worked (usually March or April).