Marigolds are grown in gardens as natural insect-repellents. We grow them at Quickcrop to repel insects from our polytunnel.
Marigolds are prolific annuals that can add color to any garden. You can choose from a wide range of colors and sizes. The colors include orange, yellow, mahogony, crimson, some bicolors and even white.
Though Marigolds are easy to grow, some factors are to be considered when growing them:
Marigolds can grow in full sun to partial-shade, but it is preferable to plant them in sunny locations as shading may have an adverse effect on flowering.
Marigolds grow best in moist, well-drained and fertile soil.
Grow your tall Marigold varieties 40cm apart and the dwarf varieties 20cm apart to give room to the growing branches. This will result in a uniform display.
Minimum temperature for growing marigolds is 10°C. Optimum temperature for the germination of seeds is 19°C.
Marigolds do not need regular watering but require so during the dry spells. Be careful not to sprinkle water on the flowers of tall varieties, otherwise they become water-logged and soft. It is better to water Marigolds during the early morning hours so that there is sufficient time for the water on the foliage to dry up.
Marigolds do not require fertilizers if the soil is rich in organic material. For poor soils, you can add a slow-acting, granular fertilizer(about 1 teaspoon per plant), but be careful not to add an excess of fertilizers which may result in an increased growth of foliage instead of flowers.
When the marigold seedlings are tall enough, spread a 2 or 3 inch layer of some organic material such as dried grass, wood chips or chopped leaves on the soil around them. This mulch reduces weeds, retains moisture in the soil, cools the soil, and fertilizes the soil as it decomposes.
Insects and Pests
Marigolds have a pungent odor, so they are not troubled by insects, but during the wet season, they can be visited by slugs. Slug pellets would solve the problem.