Break up the soil to a depth of 10 inches and blend it in with compost at least two weeks before planting day. In addition, add 1 lb. of a 10-10-10 fertilizer per 100 square feet of flowerbed. If you have clay soil, mix in 2 inches of pea gravel to improve drainage. Smooth out the surface with a rake and water the soil.
Plant either the seeds or seedlings in full sun when the ground warms up in the spring. Water the soil. Continue to give your portulaca plants 5 gallons (1 inch) of water every week until frost kills them in the fall. Seeds germinate in about 14 days.
Add a 3-inch layer of mulch to the flowerbed after planting. This will help conserve moisture and reduce weeds. When any weeds sprout, pull them right away.
Apply 1/4 lb. of a 10-10-10 fertilizer per 100 square feet of flowerbed two months after planting. Water the soil as well as the plants to remove any fertilizer residue from the foliage.
Cut the spent flowers that have gone to seed if your plants stop blooming. This will encourage flower production again.