Here are my tips on how to sow and grow snow peas which are the same tips for sugar snaps and peas:
Outdoor Sowing Tips:  1) Soak the seeds overnight (6 to 12 hours) to speed up germination and/or wrap the seeds in a damp paper towel and put them in a ziplock overnight. Don’t soak the seeds too long because it breaks down the seeds. I prefer to soak the seeds for a max. of 6 hours. 2) Since I practice square foot gardening, I sow the seeds about 1 inch deep and 2 inches apart. Don’t forget that snow peas prefer soil temperature between 45° and 75°F for germination. 3) Cover the area where you planted the seeds with netting or a row cover to keep the birds from eating the seeds.
Indoor Sowing Tips: Most seed packets don’t encourage indoor sowing for snow peas, but I do it all the time – I am such a rebel!  1) Soak the seeds overnight (6 to 12 hours) to speed up germination and/or wrap the seeds in a damp paper towel and put them in a ziplock overnight. 2) Put the seeds in seed trays about 1 inch deep under grow lights until the snow pea shoot is about 2 to 3 inches high. 3) Carefully remove the seedling and transplant them 2 inches apart after you harden them off. Â
Growing Tips: 4) Hill the soil around the row of snow peas so they don’t sit in too much water especially during the spring rainy season. 5) If you are growing pole snow peas, be ready with your trellis. I am using my cattle fencing trellis this year. 6) Keep the snow pea seedlings and plants moist but not soggy by using a drip system.  7) No matter what I am planting above ground in the spring, I am ready for temperature swings with my garden fabric and hoop tunnels.
Don’t forget that snow peas are part of the Legume Family and are a Pod veggie just like English peas.
