Cilantro Growing Information Coriandrum sativum Direct Seed: After last frost until 8 weeks before first frost. Soil temperature for germination is 60-75° F. Sow every 2-3 weeks for continuous harvest. Spacing: Sow ½” apart in rows 8-12” apart at ½" depth. Does not need to be thinned. Can be used for leaf or coriander seed production. For seed production, thin to 2-4" apart. Growth needs: Can be heat-sensitive, so look for bolt resistant varieties for hot weather production. Does well in well-drained soil that is fertile. Harvest: When leaves are of desired size and height before flowering. Seeds typically develop 3 months after planting. Make sure seeds fully dry down on plant or harvest as fresh green coriander.