Difference between Cosmos and Marigold
In courtyard flower planting, Cosmos and Marigold are often confused as the same type of plant. This article systematically sorts out the essential differences between these two Compositae plants from three dimensions: morphological characteristics, growth habits, and horticultural applications, supplemented by high-definition comparative charts to help readers visually distinguish them.
Difference in Morphological Characteristics
Comparison of Plant Structure
Cosmos (Cosmos bipinnatus) is an upright herbaceous plant belonging to the Cosmos genus, with a plant height that can reach 1-2 meters. The stems are delicate and branched, presenting an elegant plant structure.
Marigold (Tagetes erecta), as a typical dwarf variety, has a plant height controlled within the range of 50-150 centimeters. The stems are sturdy and upright, with distinct longitudinal ridges on the surface, presenting a compact plant structure.
Leaf Morphology Comparison
Cosmos leaves are twice pinnately deeply lobed, with the lobes in a fine thread-like linear arrangement, and the leaf surface is thin and translucent.
Difference between Cosmos and Marigold
Marigold leaves have sharp锯齿 edges, with lobes in a long elliptical lanceolate shape, and the leaf texture is thicker and has a special odor.
Comparison of Flower Characteristics
Cosmos flowers can reach a diameter of 10 centimeters, with ligulate petals 2-3 centimeters in length, showing a gradient effect of pink, white, purple red, and other colors, with the central tubular flowers in golden yellow.
Marigold flowers have a typical spherical head inflorescence, with ligulate petals about 1.4 centimeters in length, and flower colors mainly in orange and golden yellow, with some varieties having dark orange patterns.
Difference in Growth Habits
Temperature Adaptability
Cosmos has strong cold resistance and can grow normally at temperatures above 5℃; Marigold requires an environment above 15℃, as low temperatures can easily cause plant frostbite.
Light Requirement
Both are full-sun plants, but Marigold has brighter colors in strong sunlight, while Cosmos can extend the blooming period by 3-5 days in diffused light conditions.
Through the above comparison, it can be seen that Cosmos and Marigold have significant differences in plant structure, leaf morphology, flower characteristics, and growth habits. When planting, Cosmos should be used to create a background for flower arrangements with its tall and elegant plant structure, while Marigold's compact characteristics can be used to arrange the foreground of flower beds, with reasonable matching to form a varied and beautiful garden landscape effect.