Purslane is often considered a weed, but is completely edible and can be treated as any other herb. It is extremely hardy and spreads prolifically, so it should be kept to an herb area and removed from the regular garden. It can be grown in areas with poor soil as a cover crop and tilled in to provide nutrition. The taproot also provides aeration to soil. Purslane seeds need a cold period, so they should be sown outside about 4-6 weeks before the last average frost date, or started indoors. Inside, they will be stratified. Use a gallon plastic freezer bag with moist (not damp) soil and add the seeds to the soil. Seal in some air and shake to mix, then put the whole bag in the refrigerator for 2-3 weeks. Remove the bag and dump the contents into a seed tray (the bag should fill a 10x10 tray) and place on a heat mat. Keep the soil moist. Grow lights that can be raised and lowered are best when starting indoors - place the light source very close to the tray’s surface and as sprouts occur, lift the light. If the light is too high, the plants will become leggy and are more likely to die. If you don’t want to dump the soil, you can leave it in the bag, but you will need to add in air and mold is more likely to grow in an enclosed, moist environment.
Purslane will grow up, and then will start spreading out. Once you see 4-6 true leaves, gently separate the seedlings into individual pots (forks are helpful at lifting roots without severing them).
If planting outdoors, choose a sunny location. Purslane thrives on sunlight. Once purslane is established, it does not need to remain wet, and maintains succulent properties. If harvesting for food, consider watering the area a day or so beforehand, so that the plant has more moisture in its leaves. If left on its own, purslane produces small yellow flowers and reseeds readily. Because it is an annual, you can harvest seeds for the following year, but it will likely come back year after year on its own.