Poppies are versatile, show-stopping plants that include several varieties, from the big, bold Oriental poppy, which can grow as tall as 4 feet, to the demure Alpine poppy, topping out at about 10 inches (25 cm). Poppies are tough, easy-to-grow plants that can tolerate drought and will thrive in any well-drained soil.
Prepare the soil for planting poppies. Select a spot where the poppies will be exposed to bright sunlight for most of the day. If you live in a hot climate, select a spot where the poppies will be protected during the intense heat of the afternoon. A well-drained spot is crucial, as poppies will rot in waterlogged soil, especially during the winter months.
Cultivate the soil, using a shovel, garden fork or rototiller. Work in 2 to 4 inches (6 to 10 cm) of manure or compost if the soil is poor or doesn't drain well.
Place the poppy seeds in a small container such as a pill bottle. Add about a teaspoon of sand or sugar for every seed packet for scattering the seeds evenly. Poppy seeds are tiny, and the sand or sugar will make it easier to plant the seeds evenly.
Make a shallow trench in the soil with a stick or a hoe. Sprinkle the poppy seeds evenly in the trench, then cover the seeds with a light dusting of fine soil. Don't bury the seeds, as too much soil will block available sunlight and prevent the tiny poppy seeds from germinating.
Water the newly-planted poppy seeds after planting. Use a hose and spray nozzle or a watering can to prevent washing away the poppy seeds. Keep the soil lightly moist until the seeds germinate, which should take approximately 10 to 15 days. After the seeds germinate, water the poppies only during hot weather.
Thin the poppies when the plants are 1 to 2 inches tall (3 to 6 cm) by cutting out the weaker seedlings at the base using garden sheers, leaving 6 to 10 inches (15 to 25 cm) between each plant. DO NOT Pull them out as this may disturb the root systems of the neighboring Poppies you're trying to keep.
Fertilize the poppy plants once every month during the growing season. Use an all-purpose granular or liquid fertilizer, and apply the fertilizer according to the recommendations on the package.
Control weeds by spreading 2 to 3 inches (6 to 8 cm) of organic mulch around the plants. A mulch such as bark chips will look attractive, and will keep the soil moist
Deadhead the poppy flowers as the blooms fade and wilt. Removing the spent blooms will encourage the plant to keep blooming throughout the summer.