Marigolds (Tagetes sp.) are an easy-to-care-for, colorful annual, often used for borders, containers and color massing. Nearly all marigolds bloom heartily from early summer until the first hard frost, according to the Clemson Cooperative Extension, preferring full sun and healthy, well-draining soil. Other plants grow well with marigolds. There are several ways to select plants that grow well with marigolds.
Perhaps the best-known example of companion planting is the Native American method of planting corn, beans and squash together. These "three sisters" complement and protect each other, making all three plants thrive in the same location. Marigolds are widely used in companion planting and are thought to deter many pests. According to the Alabama Cooperative Extension System, marigolds help keep nematodes, whiteflies, Mexican bean beetles and tomato hornworms at bay. Marigolds make a fine companion for any plant plagued by these pests, including tomatoes, corn, potatoes, beans, and hot-house and greenhouse plants.
Another way to select plants to place beside marigolds is choosing those of a complementary color. As the DePaul University explains it, in art theory, a complementary color is one that shares no color with its complement. For example, green complements red because it's made of blue and yellow while red is not. Following this theory, yellow and orange marigolds "pop" beautifully alongside blue and purplish flowers like bachelor buttons, alliums, asters, anemones, bluebells, columbine, delphinium, hydrangea, iris, pansies, phlox, salvia, violets and veronica.
Plants with Height
Because marigolds are short plants growing 6 inches to 4 feet tall, according to the West Virginia Extension Service, they also work well in front of taller plants. Marigolds, particularly taller varieties, help hide unattractive, bare stems and add interesting layers to the garden. From this point of view, iris, morning glories, lavender, baptisia and clematis or any vine are excellent choices. Marigolds also do a nice job of covering the soil in a pot containing taller plants like dwarf trees.
Fill in Plants
Planners use marigolds to cover up the location of spring-blooming plants, especially those that die back completely after blooming, as many spring bulbs, such as hyacinths, tulips, daffodils, crocus and scilla. If planted when the spring bloomers begin dying back, marigolds help hide the dying plants and offer more green foliage to the garden. Rarely do marigolds need fill in plants themselves, since most varieties bloom until late fall.