Different types of big flowers can make a stunning display in your garden with the addition of as few as one or two plants because of the heightened visual impact of larger blooms. Whether in the form of shrubs or on tall erect stems, big colorful blossoms come in a variety of species, colors and sizes. Choose plants according to care requirements that match up with your local climate.
Sunflowers (Helianthus annuus) are annual plants that bear big flowers. Displaying yellow, maroon or orange petals, the center of the flower head consists of florets that develop into seeds with inedible husks and edible kernels within, considered the "fruit" of the sunflower plant. The large flower head of the sunflower can grow up to 12 inches in diameter atop erect stems that reach up to 10 feet in height. Sunflowers thrive in direct sunlight and moist, well-drained soil. Sunflowers reach maturity four months after initial planting and seeds may be harvested.
Southern magnolias (M. grandiflora), also referred to as bull bay, are one of the three major categories of magnolia plants. Prized for their showiness and sweet fragrance, the magnolia flowers of the southern magnolia grow to a diameter of 8 to 12 inches and display a creamy-white hue with wide petals; foliage is dark green with contrasting color on the underside of leaves, such as copper or light green. This evergreen tree has a bloom time of May through June and thrives in full sun with moist soil, or partial shade if soil is not kept consistently moist.
Dahlias (Dahlia pinnata) are succulent plants that yield large flowers depending on the variety. Displaying flowers in all colors of the spectrum but blue, varieties of "dinner plate" dahlias grow up to a diameter measuring 12 or more inches. Thriving in full sunlight, dahlias prefer well-drained soil and abundant moisture. With a bloom time during the month of July, dahlias grow to a height of over 15 inches and may need support, such as loose binding to a stake, to keep them from falling and bending.
Annabelle hydrangeas (Hydrangea arborescens) are deciduous shrubs that produce big flowers. Displaying white flowers and dark green foliage, hydrangea blossoms grow as a spherical collection of smaller flowers on a corymb (small circular expansion of stems that act as a support) that measures 8 to 12 inches in diameter when flat, according to the NC State University Cooperative Extension. Thriving in full sun to partial shade, Annabelle hydrangeas prefer moist, well-drained soil and perform poorly in drought-like conditions. With a bloom time of late June through September, this shrub grows to a height of 3 to 4 feet and a width of 3 to 5 feet.