I think I mentioned this last year, but wanted to throw it out there again. You’ll find this noted elsewhere online, I found it last year when growing peas for the first time.
Since peas can be started so early (apparently sometimes they will even sprout and grow through snow), the soil conditions can be all over the map. So I sprout my peas indoors first. It’s really simple. Take some paper towels or cloth and get it moist, but not wet. This year I used an old diaper. Put the peas inside. They like to roll around, so it can be helpful to roll up the sides in some fashion to keep them in. Put the paper towel or cloth inside a plastic bag or really anything that can hold some moisture in. I find a gallon ziploc works great and we always have used ones around. Just leave enough of a gap in the container or bag for some air to get in and out. You are basically making a little greenhouse.
After a couple of days, start checking them. As soon as you see sprouts you can plant them outside. Be careful with them at this stage as the little sprouts can be pretty fragile. If you break them off, that seed is done.
They seem to like a diaper better than a paper towel because this time a bunch sprouted by today, probably 60-70%, and I just started them during last weekend. Some of the sprouts actually grew through the diaper cloth. They are ready to go!