Photo from the web Follow this exact month by month spring guide to sow seeds at the right time. Start indoors in March, move young plants outside in April, and plant your heat loving crops in May. You will get healthy vegetables and flowers without losing plants to cold spring frost. What to Plant in Spring Month by Month Starting your garden requires knowing your local warm and cold weeks. Spring planting relies on matching crop cold tolerance to outdoor night temperatures. Hardier vegetables survive light frosts, while delicate summer plants need completely warm soil. Set up a simple indoor starting station with bright light standard trays. Use this clean schedule for successful spring growth: March indoors: Sow tomatoes, peppers, and eggplant seeds indoors under lights for eight weeks of growth before final spring planting. March outdoors: Direct sow peas, spinach, kale, and radish seeds directly into outdoor soil as soon as it thaws. April outdoors: Sow carrot, beet, ...