Traditionally, a courtyard garden is partly or completely paved. One fairly inexpensive way to create that look is to sink stepping stones into existing grass; garden centers and stone yards sometimes offer bargain prices on broken or chipped pavers and flagstones. Gradually replace grass between the stones with rooted cuttings of a low-profile, aromatic herb such as creeping thyme (Thymus serpyllum spp.), which is hardy in U.S. Department of Agriculture (USDA) plant hardiness zones 4 through 9, or a low-growing ground-cover such as bugleweed (Ajuga reptens and cvs.), which is hardy in USDA zones 3 through 9. Other inexpensive, hard-surface coverings include gravel, cement pavers and stamped or embossed concrete.
Only very few plants are needed to transform a courtyard into a garden. A single raised or stone-edged bed of perennials, a small tree in a container or a group of planters holding annuals conserve space and care-time as well as money. Bargain-hunt for a single, large planter in which you can center a small evergreen such as a "Green Mountain" boxwood (Buxus "Green Mountain"), which is hardy in USDA zones 4 through 9. Edge the planter with trailing vinca (Vinca minor spp.), which is also hardy in USDA zones 4 through 9. Plant johnny-jump-up (Viola tricolor) close to the rim for a ring of yellow, purple and white, small, pansylike flowers that bloom spring, summer and fall. Johnny-jump-up can grow in USDA zones 3 through 9; it is a self-seeding annual in cool zones, a biennial in some locations and can be a short-lived perennial in warm zones.
A planter centered on "Golden Sword" yucca (Yucca filamentosa "Golden Sword"), which is hardy in USDA zones 4 through 11, establishes a xeric or tropical look. Add a sun-loving million-bells calibrachoa such as "Callie Rose Star" (Calibrachoa "Callie Rose Star"), which is hardy in USDA zones 8 through 11, for vivid, red-and-white coloring from early summer through fall.
Although not necessarily hidden behind high castle walls, a courtyard garden is landscaped to maximize privacy as well as relaxation. Hanging prefabricated trellis panels or split-bamboo roll fencing with wire between posts creates effective screening at a low cost. Join lengths of polyvinyl chloride (PVC) pipe with premade elbows to make frames for outdoor-grade canvas panels; add wheels to make your screens moveable. Vinyl-coated mesh garden fencing makes a quick and inexpensive backing for training privacy-screening vines. Traditionally, a courtyard garden room remains open to the sky
As an outdoor room, ideally a courtyard garden offers seating and perhaps a small table. Mismatched garage-sale metal chairs can be refurbished with rust-resistant paint and seasonal-sale cushions. Old kitchen chairs from an attic need only shabby-chic painting to serve for one or two seasons. A cluster of odd chairs, benches and tables can be unified by painting everything a single color; although black is traditional, a soft green or restful blue is equally effective. Make a bench by laying a board over stacked concrete blocks to extend seating or enhance a narrow space. Courtyards were furnished with whatever came to hand long before matching patio sets existed; let eccentric finds serve as both furniture and outdoor art in your courtyard garden.
One function of a courtyard in a Mediterranean home was to provide respite from heat and dust, a goal that was often accomplished with a fountain or small pool. Since Roman times, architects have recognized the cooling effect of the sound of flowing water on heat-worn listeners. Today, ancient engineering has been replaced by electricity, producing plug-in or battery-operated, self-circulating fountains small enough to sit on a living-room table. Yard sales, garden centers, big-box stores and even dollar stores are possible sources for a cool-sounding fountain. Alternatively, provide both water and natural activity by setting up a birdbath. Birds will visit for a welcome drink or a fluttery bath, especially if you hang a bird feeder in another part of your garden. Use a resin copy of a stone birdbath, or mount a large, clay saucer on an overturned flowerpot. Change the water daily, and expect visitors.