Portulaca flowers tolerate many kinds of soil but prefer sandy, well-drained soil and love the full sunlight. These plants are excellent for high heat and drought tolerance, and will seed and spread themselves very well. Some control methods may be needed to keep portulaca plants from becoming invasive to areas where they are not wanted. From personal experience in my garden areas, I can tell you that these wonderful plants do spread easily and very well. I planted some seeds in the gravel mulch at the end of one of my rose beds and the following summer had portulaca plants coming up in several other areas where I had not planted any such seeds.