The marigold, or Tagetes, originated in South America and New Mexico. This vibrant, annual flower grows up to 4 feet tall in optimum growing environments and has showy blossoms of orange, yellow, red and cream colors. A marigold requires moist -- but not overly wet -- soil to thrive and tends to not continuously flower if in shade. Marigolds go through different stages before actually blooming. Understanding these stages and the basics of marigold growing will ensure that you have many showy blooms in your garden.
Marigold varieties are classified by their characteristics, such as large, semi-dwarf and dwarf. Four main species of marigolds are available. African marigolds grow up to 14 inches tall and have blossoms up to 3 1/2 inches in diameter. French marigolds come in large and dwarf varieties. This species ranges from 12 to 16 inches tall with blossoms up to 2 inches in diameter. Triploids are a hybrid of the African and French varieties. Triploids' blossoms are about 2 inches in diameter, and the colors vary depending on the climates in which they are grown. Single marigolds look almost like a daisy and have a long stem.
Plant marigolds in seed pots or flats where they will have good drainage. Cover seeds with 1/4 inch of vermiculite or perlite. Rather than wetting the soil directly, use a spray bottle to keep the soil moist. Keep the soil temperature around 60 to 70 degrees Fahrenheit.
Germination: Stages 1 and 2
If provided with the right climate, soil conditions and lighting, marigold seeds begin to germinate in three to five days, which is part of stage 1. Promote germination in your seeds by covering the seed pots or flats to block out light. Test the soil pH to ensure that it is 6.0 to 6.2. Stage 2 occurs when the radicle emerges from the soil after germination.
Cotyledons: Stages 3 and 4
When the cotyledon, or the first green stem, appears at stage 3, begin fertilizing the marigolds with 50 to 75 parts per million of nitrate from calcium or potassium nitrate fertilizers, according to Auburn University. At this stage, marigolds can start receiving full sunlight. Temperatures should remain between 60 and 65 degrees Fahrenheit to promote flowering and to allow the stem to continue to grow. At stage 4, the marigold's cotyledon will unfold and make way for flowering.
Flowering: Stage 5
Flowering occurs in marigolds 45 to 50 days after planting, according to West Virginia University. At this time, you can transfer a marigold to a garden or pot. Keep the soil moist and remove spent flower heads to promote continuous flowering. Temperatures should remain 60 to 72 degrees Fahrenheit during the day and 65 degrees Fahrenheit at night.