Tagetes patula

The Wild French Marigold, in Latin Tagetes patula, is an annual plant both decorative and useful to gardeners. It is one of the easiest flowers to succeed with and its warm flowering extends throughout the summer, and even until the frosts. It is an annual plant that offers single flowers in shades of golden yellow to orange, sometimes adorned with small mahogany spots at the base. It has nematocidal properties and is a natural method to combat nematodes. It can also be used as green manure to improve soil composition. Foolproof, it will show itself worthy, from the vegetable garden to the most elaborate garden. Sow and cultivate in well-drained soil, in full sun or partial shade.

Tagetes patula is an herbaceous annual plant from the Asteraceae family native to tropical regions of the Americas, from Mexico to Bolivia. It forms a small bushy clump with a spreading habit, about 30-35cm (12-14in) in all directions, covered with dark green, highly dissected foliage that is strongly aromatic and may be disagreeable in odour. The flowering period extends from June to October, when faded flowers are regularly removed. Its 'flowers' are actually simple inflorescences in solitary heads, about 4-5cm (2in) in diameter, composed of decorative ligulate rays located at the periphery of the head, and surrounding a compound centre of tiny fertile flowers in a bright yellow-orange colour. This plant easily self-seeds in the garden.

In the vegetable garden:

The scent of French Marigold foliage and the substances secreted by their roots repel certain pests, especially nematodes, from crops. That is why these plants are often installed among the vegetables in the vegetable garden. Plant 2 Tagetes for every 6 Tomato plants, they will protect them from these pests.

French Marigolds can also be used as green manure. For this, they need to be sown broadcast on the plot of land where the soil is to be improved. Well-developed plants, but not yet bearing seeds, will be mowed and buried. This addition will enrich and fertilize the soil, thus promoting subsequent crops.

In ornamental gardening: 

French Marigolds are star plants in summer flowerbeds. They are sometimes criticized for their garish colours and their refined habit, but they are so cheerful, easy to succeed with, and floriferous that it would be a shame not to enjoy them in borders and containers. They can be installed sparingly amidst the grey foliage of wormwood and lamb's ears (Stachys), or flooded with greenery, by combining them with tansies, Kochia childsii, or small grasses that will temper their flamboyant colours. French Marigold is also an edible flower that can be enjoyed in salads, soups, or desserts. Some say its flavour resembles that of passion fruit.