Marigolds have many uses. Plant rows of large American or hybrid types to serve as small hedges along walks or to divide garden areas. Plant them at the back of a flower bed to serve as a backdrop to shorter flowers. Use the French and signet types for edging along walks or at the front of the garden bed. Tuck them among shrubs to brighten an area. The smaller French marigolds, especially dwarf versions, and small flowered signet marigolds are perfect for windowboxes and planters. Mixed in with other colorful annuals they are especially appropriate for sunny patio and pool areas.
Although some people object to the strong odor of their foliage, marigolds, especially the showy American and triploid types, make attractive additions to summer or fall bouquets and arrangements. Choose varieties that have odor-free leaves. Cut newly opened blooms early in the morning and put them in warm water immediately. Be sure to strip the leaves off of the stems below the water level so that they do not rot and foul the water in the vase while they are on display.
For more information see the files on Keeping Cut Flowers and Cut Flower Supplies
Air dry marigolds for indoor use by cutting blooms when they are at their peak. Remove all foliage from the stems then tie them together so they can be hung upside down in a dry, warm place such as an attic. Large double orange types are best for air drying. Although they will shrink, they hold their color for strong effect in dried arrangements. Insert a wire up each hollow stem and into the flower head before hanging them to dry so that they are easier to work with after they are dried. Smaller types dry better in silica or sand.
For more information see Drying Flowers and Flower Drying Supplies
Of all the marigolds, only the dainty flowers of the signet types have a culinary use. Their spicy, tarragon-flavored petals add zip and color to a salad. Cathy Wilkinson Barash, noted authority on edible flowers suggests making marigold butter by chopping petals finely and mixing them into softened butter. Roll the butter into a log shape, refrigerate up to 2 weeks or freeze. Slice off thin curls to garnish fish dishes. Chopped signet marigold petals can also be used to garnish deviled eggs or steamed vegetables.