Loosen the soil to a depth of approximately 15 inches using a garden fork or tiller.
Add between 2 and 4 inches of compost.
Mix the compost into the soil using your tiller or garden fork.
Make a hole in the ground that's roughly twice the diameter of the container that the poppy seedling comes in. The hole should be deep enough so that the plant can sit with the root ball being roughly level with the surface of the soil.
Place the plant in the hole, then carefully fill in the hole.
Add the rest of your plants using the same procedure, making sure that there's at least 2 feet of separation between each one.
Water all the poppies to help them get started.
Cover the soil with a thin layer of compost every spring, then add a 2-inch layer of mulch on top of the compost.
Add a layer of mulch 4 to 6 inches deep during winter when the ground starts to freeze.
Remove the mulch as the weather warms.
During growing season, from late spring to early summer, water the plants only sparingly. Too much water can kill them. In the hottest months of summer, the poppies will move into their dormant phase. During this time, water the plants only during periods of drought.