Trees provide enclosure to a garden space, framing views and casting shade in summer to create a cool respite for plant and property owner alike. Red flowers on trees accentuate the red garden theme, particularly to present flower color at times of year when annual or perennial flowers aren't blooming. Red maple (Acer rubrum), red buckeye (Aesculus pavia), Persian ironwood (Parrotia persica), bottlebrush (Callistemon citrinus) and various red-blooming selections of crape myrtle (Lagerstroemia spp.), such as Tonto, Dynamite and Watermelon Red. Various cultivars of crabapples (Malus spp.) display ornate red blossoms, such as Adams, Prairiefire and Liset.
Planting various shrubs provides the intermediate structure and height between tall trees and the lower growing annuals and perennials in the garden. Red-blooming shrubs include common camellia (Camellia japonica), Cherokee bean (Erythrina herbacea), anise tree (Illicium floridanum), spicebush (Calycanthus floridus) and various selections of roses (Rosa spp.). Cultivars of ref flowering dwarf crape myrtles (Lagerstroemia spp.) with vivid red flowers include Victor and Ruby Dazzle.
Perennials provide reliable herbaceous foliage and seasonal red flower color in the garden. Perennials cost less than annuals since you don't need to replace them each year. Among the finest red-blooming perennial flowers are peonies (Paeonia spp.), montbretia (Crososmia spp.), columbine (Aquilegia canadensis), beebalm (Monarda didyma), bleeding hearts (Dicentra amabilis), hardy hibiscus (Hibiscus mocheutos), red sage (Salvia spp.) and yarrow (Achillea spp.). Many red cultivars of tulips (Tulipa spp.) exist, and will persist as perennials in regions with cool, moist soils in summer.
To fill in the gaps between trees, shrubs and perennials, gardeners use annual flowers, which profusely flower from spring until the killing fall frost. The choice of red-flowering annuals is immense, as many cultivars exist to provide a wide array of red blossoms among different species. Salvia, petunia, wax begonia, flowering tobacco (Nicotiana spp.), geranium (Pelargonium spp.) and cockscomb (Celosia spp.) are easy-to-grow plants that display a wide array of red blossoms. Summertime bulbs such as gladiola and dahlia can also provide red flowers in the garden.