This study was executed to (1) Evaluate the ability of sunflower (Helianthus annuus), sorghum (Sorghum bicolor) and elephant grass (Pennisetum purprueum)
to accumulate Co in their tissues. (2) Define to what extent these plants can clean-up a Co-contaminated sandy soil. Two experiments were conducted, the first was nutriculture (hydroponic) experiment and a pot sandy soil one. Sunflower absorbed appreciable quantities of cobalt in both experiments. Elephant grass was superior in accumulation of cobalt to the other plants particularly in the soil experiment. Sunflower and elephant grass could be considered hyperaccumulator plants for cobalt and could be used to remedy Co-contaminated soils. Using phytoremediation may be of less cost as compared with other remediation techniques. Using chemical extraction in sequences may remove high amounts of cobalt and be most effective as compared with phytoremediation. Extraction of heavy metals with EDTA was more effective than using AB-DTPA.