|This familiar agricultural crop is used in peanut butter, peanut oil, candy and other products. Plants look like small sweet-pea bushes and grow best where summers are long and hot. After yellow flowers fade, a shoot develops and grows down into the soil, where peanuts form. Plant in light soil or sand so shoots can penetrate. In cold areas, start seeds -- unroasted peanuts -- indoors 4 weeks before last frost or wait to plant outdoors after last frost and ground has warmed. When plants yellow at the end of the season, loosen soil and pull up to harvest. Hang in a warm, shady location for 2-3 weeks to cure, then strip off peanuts.