WHEN TO PLANT MARIGOLDS

• Young French and signet marigolds can be planted from spring through midsummer, but the tall African marigolds are best planted right away in the spring (after danger of frost has passed) because they are slower to mature and produce flowers. Find local frost dates here.
• Sow seeds directly into the garden once the soil is warm in the spring. You can start seeds indoors, but they germinate so easily outside that there’s really no advantage. The exception is African marigolds, which are best bought as young plants or started indoors about 4 to 6 weeks before your last frost date.
• Marigolds sprout within a week in warm weather and plants typically produce blooms in about 8 weeks.

CHOOSING AND PREPARING A PLANTING SITE

• Marigolds thrive in full sunshine and can often withstand very hot summers. African and signet marigolds are drought tolerant, while French marigolds are more tolerant of wet conditions.
• If planted in shade and cool, moist areas, marigolds are prone to powdery mildew and won’t bloom well. 
• Though they grow in almost any soil, marigolds do best in moderately fertile, well-drained soil. 
• Prepare the soil by digging down about 6 inches to loosen it. Remove stones. 

HOW TO PLANT MARIGOLDS

• French marigolds can easily be started from seed, while African marigolds are best purchased as young plants (when started from seed, they can take a long time to flower).
• Optional: If soil is nutrient-starved, add some slow-release (granular) fertilizer in the planting hole. A 5-10-5 works fine.
• Moisten the soil, then sow seeds 1 inch apart and no more than 1 inch deep.
• While still small, thin the seedlings. Space French and signet types 8 to 10 inches apart. The larger African marigolds should be at least 10 to 12 inches apart.
• If planting transplants, thoroughly water each plant after planting in the garden.
• If planting in containers, use a soil-based potting mix. Either mix in slow-acting granular fertilizer at planting time or plan to water with diluted liquid fertilizer periodically. Take care to space properly; marigolds grown in containers can become crowded.