When Do Marigolds Bloom in Southern California?

Typical Time Period

• With mild Southern California winters, you can easily plant both seeds and seedlings directly in your garden as early as March -- heavy rains and cold are typically over by early spring. Because the days are lengthening and warming, you could see blossoms as early as May. Even late spring and early summer plantings offer blossoms into late summer and early fall because temperatures in this region often remain warm well into September.

Sowing Seeds

• Marigolds fail to flower prolifically if you do not sow the seeds correctly in your garden. For example, most marigold varieties need plenty of space between seedlings to provide enough natural resources -- water, moisture and oxygen -- for healthy stem, foliage and flower growth. In general, space seeds approximately 1 inch from one another and remove any sickly or small plants to maintain a wider 10- to 12-inch spacing during seedling growth. Taller marigolds need 2 to 3 feet of space between plants.

  Sowing seeds in early spring allows them to take advantage of warm weather for consistent flowering until mid- to late fall. When sown 1/4 inch deep, the seeds have a chance to absorb surrounding moisture for a rapid seven-day germination period. Then only two months of growth are needed before flowers emerge.

Deadheading

• Do not be wary of cutting flowers for indoor displays or simply removing spent blossoms. Marigolds detect removed flowers and quickly generate new ones to improve their reproductive chances -- deadheading actually produces more flowers compared to gardens left untouched. However, do not over-fertilize your garden. Marigolds thrive in hot locations where soil has low-nutrient reserves. Too many nutrients actually decrease flowering because marigolds redirect their energy into vegetative spread rather than reproductive growth when fertilized.

Moisture and Sunlight

• Sunny Southern California spring and summer periods provide the six hours of daily sunlight necessary for successful marigold blossoming. Position marigolds in a south- or east-facing location in the garden -- do not allow any shading to block the sunlight, such as from nearby trees. You can even plant marigolds close to concrete walkways. Urban heat and daily sunlight encourage summer flowering with consistent watering. While marigolds need well-drained soil, the ground must be moist to support the growing flowers. If you allow the area to dry, flowering fails and leaves wilt. Use mulch around the flowers to maintain soil moisture.