With one architectural feature, such as a wooden bridge or small Japanese-style shed, you can add elements of water and rocks to create the backbone of a Japanese garden. Plants, particularly evergreen or seasonally flowering types, complete the landscape. Choose species or cultivars that grow well in your climate whether it provides a brutally cold winter or is milder and subtropical. Make substitutions of hardy plants that look similar.
Trees provide shade and vertical beauty to the garden. Evergreen types, especially pines (Pinus spp.), anchor the Japanese garden in all seasons and create visually contrasting backdrops for other plants that flower or change their leaf colors. Deciduous trees also hold snow or ice on their branches to create interesting silhouettes in winter. Flowering trees to include are ornamental cherries (Prunus spp.) and a kousa (Cornus kousa) or flowering dogwood (Cornus florida). Maple trees also need a prominent setting, especially the smaller-sized Japanese or full-moon maples (Acer palmatum and Acer japonicum, respectively). Maples attain handsome branching structures as well as provide vivid fall foliage displays. Other suitable trees include ginkgo, deciduous magnolias and witchhazels (Hamamelis spp.).
Evergreen shrubs add visual weight to the Japanese garden, particularly in winter. Rhododendrons and azaleas, clipped into geometric shapes or left to grow into rustic natural forms, need to grown in this garden. Camellias, both sasanqua and common types, remain evergreen and provide flower displays in fall, winter, and spring. Hydrangea makes a sound choice as does the kerria, a deciduous shrub with yellow springtime flowers. Keep in mind some dwarfed weeping varieties of maple or redbud (Cercis spp.) may make attractive accents as can dwarf conifers, which make easy bonsai subjects. The Japanese revere flowers, so you truly have personal liberty to populate your garden with any blossoming shrub species you choose.
Herbaceous plants that flower or have ornate foliage are good choices for Japanese gardens. Irises, chrysanthemums, deciduous and evergreen ferns, astilbe, aster and peony are prized additions to the garden according to both Bowdoin College and "Small Spaces & City Places" on-line resources. If you have a water feature, including a water lily and certainly Japanese irises growing at the shoreline.
Sweeping carpets of pebbles and stone often appear in Japanese gardens, but low-growing plants can also be used to mimic the ocean's surface or a vast forest when viewed from above. Prostrate junipers and dwarf mondo grasses (Ophiopogon spp.) make low maintenance selections. Spreading ground cover bamboos (Sasa spp. and Pleioblastus spp.) are an option.
Both smaller, clumping ornamental grasses and larger, tree-like bamboos lend an air of the Orient to Japanese garden designs. Avoid spreading bamboo species (such as Phyllostachys and Semiarundinaria) to prevent invading roots and canes from choking out other parts of the garden. Small-size bamboos that are well behaved and remain as a neat clump of canes or mildly spreading include those of the genus Fargesia, Sasaella and Sasa, according to "Bamboo for Gardens" by Ted Meredith. If bamboos intimidate you, stick with upright ornamental grasses more easily purchased at garden centers.