25 Seeds Purple India Marigold Seeds for Garden Planting Grow Your Own Marigolds from Seed! Instructions: 1. Prepare Soil: Use well-draining soil enriched with compost or organic matter. Loosen the soil to a depth of about 6 inches. 2. Start Indoors (Optional): Marigold seeds can be started indoors 4-6 weeks before the last frost date in your area. Use seed trays or pots filled with seed-starting mix. 3. Plant Seeds: Plant marigold seeds about inch deep in the soil or seed trays. Water gently after planting. 4. Provide Warmth: Marigold seeds germinate best in warm temperatures. Keep seed trays in a warm location or use a heat mat to encourage germination. 5. Maintain Moisture: Keep the soil evenly moist but not waterlogged. Water from the bottom of seed trays to avoid disturbing seeds. 6. Transplant: Once marigold seedlings have developed true leaves and are a few inches tall, transplant them into larger pots or directly into the garden after the last frost date.