Marigolds are a popular choice for home gardeners because they are extremely easy to grow and maintain and they also provide long lasting blooms throughout the season. Planting marigolds is simple and, best of all, the plants only require minimal care and watering. Available in both French and African varieties, these flowers are also known for their scent, which is mild to humans but irritating to many insects and pests, which makes them great companions to any vegetable garden.
Decide if you want to work with seeds or purchase starter plants. Marigold plants can typically be found in the spring at plant nurseries, garden centers and home improvement stores. However, if you are looking to grow a hard-to-find type or heirloom variety you may opt to start the plants yourself from seed. Doing so is also considerably more economical, especially if you have a large garden. If you do choose to start from seed, be sure to allow at least seven weeks before the planting season to start the seeds indoors. Marigold seeds can also be sown directly into the ground once the risk of frost has passed.
Plant marigolds or seeds after the last frost date. To determine the average frost date in your area consult with the Farmers Almanac (see Resources) or contact your local Agriculture Extension office. Choose a location in your garden that receives full sun and ensure that the spot you've chosen has good drainage to prevent water from pooling up around your marigold plants after a rainfall or watering.
Dig a small hole a few inches deep and place an individual seedling into the hole. Cover it with soil. Plant the seedlings between 10 and 20 inches away from each other. The spacing will depend on the variety. French marigolds tend to be smaller than African marigolds and therefore would require less distance between plants. After planting add mulch around the marigolds, as this will not only provide valuable nutrients to your plants, but will also help to prevent weeds.
If you opt to start from seed plant the seeds about 1/4 inch deep and 8 to 10 inches apart from one another and cover them with soil.
Water the marigolds as needed so that they are kept adequately hydrated. A hose with a sprayer attachment is ideal, as is a simple watering can. While they are considered drought resistant to some extent, marigolds still require water on a regular basis. During extremely hot weather be sure to check on the plants and provide supplemental watering if necessary.
Entice marigolds to bloom continually once the plants are mature and established by removing the flowers that have died off, a process called "deadheading." Deadheading helps to prevent the plant from going to seed, and will ensure that the plant continues to produce new blooms. At the end of the growing season if you would like to save seeds from your flowers simply allow the flowers to die on the plant. Allow the dead flower a week or two to dry out on the plant. Remove the entire flower, carefully break it open with your hands and you will find several black and wheat colored marigold seeds that can be saved for another season. Bear in mind though that unless the seed you've saved are heirloom or non-hybrid varieties, the flowers may not grow true to type.