Marigolds are pretty flowers that come in several solid or double colors, such as orange, yellow, mahogany and an orange-yellow blend. They also come with a not-so-sweet smell that prevents them from being bothered by many of the pests that other flowers have to deal with. If you want to help out your entire growing area, plant marigolds in between other sweet-smelling plants throughout your garden to help keep away bugs.
Locate marigolds in a place that is mostly sunny. You want them to have full sunlight all day if possible.
Check to see that they are planted in well-draining soil. They don't do well in soil that is kept soggy or keeps standing water. Mix in sand to aid with drainage if needed.
Keep the soil damp. Since marigolds love the sun, their soil will tend to dry up quickly because of their location. Check often to ensure they have enough water.
Apply fertilizers to extend the life of the flowers and increase flower production. Use a slow-releasing granular fertilizer, such as a 20-10-20 blend. Typically a small amount is all that is needed for the season, about 1 tsp. for each marigold. Add the nutrients in the spring by sprinkling it over the soil. For fuller plants with lots of blooms, pinch off the heads of the first blooms with your fingers before they open.
Add mulch around the base, but not up against the flowers. This will help trap moisture in the ground for the marigolds.