Smaller cultivars, some of which have variegated foliage, are available for facing plants and ground covers. However, another selection is suggested if a formal hedge is desired—this pittosporum does not respond well to hard pruning or shearing, although frequent light pinching can help to maintain a compact habit. Allowed to grow naturally, it reaches 6 to 15 feet in height and is usually slightly wider. Fairly drought-resistant, it nevertheless appreciates adequate water and an annual light fertilization. Aphids and scale can be a problem. Medium shade to full sun is best, although it tolerates dense shade well.

Buds appear in autumn, and develop in late winter or early spring into gracefully pendulous 6-inch clusters of white or pinkish bell-shaped blossoms resembling lily-of-the-valley—hence one of its common names. IiIy-of-the-valley shrub. The flowers are long-lasting.Thin. oblong leaves. to 3 inches long and an inch wide. are pink to bronzy red as they emerge in spring.

They mature to glossy, ossy deep green, creating a tiered effect. In most climates light shade is good. but particularly in very hot climates, medium shade is best. Pieris should be sheltered from the wind and winter sun in cold areas. Soil should be rich, high in organic content, acid, and fast-draining. If pruning is ever necessary—and it never is, except to shape the plant—prune immediately after flowering. Crown rot. fungus leaf spot, a die-back fungus, lace bugs, scales. and mites can be severe problems unless controlled by appropriate sprays.

P. floribunda (Mountain Pieris, Mountain Andromeda; Zones 5 to 8  ), native to the eastern United States, is quite similar to P. japonica in appearance and requirements but more compact and smaller (2 to 6 feet high and wide), and it flowers in April. Flowers are pure white. A very old specimen in an English garden is 6 feet high and 15 feet wide. P. floribunda is less vulnerable to pests than is P. japonica.

P. ‘Forest Flame’, a 6 to 7-foot hybrid between P. japonica and P. forestii, has vivid scarlet new growth and is hardier than P. forestii.

P. forestii (Chinese Pieris) is more tender than other species. It closely resembles them but is denser and larger, and its new growth is more brilliantly colored. Hardy to Zone 8.

The fertile frond resembles a cinnamon stick. It emerges first, and after releasing its spores it turns golden brown, withers, and lies on the ground through the summer.

The sterile fronds appear in late spring, stay green all summer, and turn brown with the first fall frost. This fern requires a slightly acid (pH 5.5 to 6.5) soil that is kept evenly moist. It spreads slowly, and because of its height, it is best used as a background plant.

Small, pale purple flowers, mostly hidden among the leaves, appear in July and August, followed by pea-sized blue fruit. Mondograss spreads by means of fleshy subsurface stems. The growth rate is quite slow until the plant is well established.

A miniature version of O. japonicas, growing about half as high, is O. j. ‘Nana’. O. jaburan is similar in size and growth habit to Liriope muscari, and is often mistaken for it. The chief observable differences are that O. jaburan has green instead of brownish stems, and white, more drooping, less tightly clustered flowers. O. `Variegatus’ is a low-growing variety with white, striated leaves.

These plants are adaptable to most well-drained soils. In coastal areas they will grow in full sun; elsewhere they look and grow best in medium to light shade. All need regular summer watering. Mondograss needs more frequent watering if exposed to full sun in a mass planting. New plants can be started by dividing clumps. Set divisions of mondograss 6 inches apart, O. jaburan 12 inches apart.

Mondograss looks good as a sizable planting under the shade of a large tree. In a shaded patio setting, a few dozen plants, placed about 8 inches apart with baby’s-tears (Soleirolia soleirolii) in between, produce a lovely, cool effect. It also makes a handsome border along paths, and is useful in defining and separating lawns from flower beds. O. jaburan is most effective where its attractive flowers (good for cutting) and violet-blue fruits can be seen close up, as in entryways, near fences and buildings, and under trees.

Nierembergia is outstanding in large beds or as a 6 to 12-inch ground cover, but is even more elegant and appropriate grown in small patches in the rock garden. It behaves well as an edging to a border or walkway, and can be planted in pots, hanging baskets, and window boxes. It is also a logical substitute for trailing lobelia where the latter dies out in the heat.

For its easy care, long-season blue-violet color, and restrained size, the cup flower deserves greater popularity.

It needs fertile, sandy, moist, well-drained soil that is high in organic matter, and light shade to full sun. Shade is preferred in areas with hot summers. Keep the plants moist, but be careful not to overwater.

Often touted as powerfully fragrant. the day-blooming hybrids available today are sorely disappointing. Occasionally a fresh, sweet scent can be detected in the vicinity of a bed. especially on cool evenings; but the famous perfume. sadly, has been lost. It can be found only in the tall. old-fashioned. evening-blooming kinds.

Consider nicotiana when looking for a tall ( 12 to 36 inches), delicate statement in the mixed border. It is surprisingly effective planted in clumps in large pots. Do not grow nicotiana near where you intend to grow tomatoes; it attracts many pests and diseases that may attack tomatoes, such as tobacco mosaic virus.

While the hardy nicotiana will be little troubled, the tomatoes may not survive.

Nicotiana is gaining favor as an alternative to petunias in areas where the humidity-related disease botrytis can snip the blossoms off for several weeks in late summer.

It does best in fertile, well-drained, moist soil that is high in organic matter. Medium to light shade is preferred, but it will tolerate full sun in humid climates; flowers will fade some in full sun in dry climates. Fertilize regularly, and keep the soil moist. It will self-sow freely, but is not difficult to control.

With a few hours of sun a day, nandina frequently has brilliant crimson to purple foliage in the fall and winter. Often reaching 8 feet in height and 21/2 to 3 feet in width, nandina is effective as a hedge or screen, in a mass or grouping, or as a solitary specimen in an entryway or container. It is particularly effective when backlit. Nandina will lose its leaves at 10°F, and will die back to the ground at 0°F, although it quickly recovers the following season. In the northern limits of its range, it is best used as an herbaceous perennial.

Since crossfertilization improves fruiting, try to plant nandina in groups. It performs well in nearly any soil, in medium shade to full sun, although some protection is required in particularly hot climates. Established plants tolerate drought well. Prune out old, leggy canes annually to encourage density. Nandina competes well with tree roots, and is little troubled by pests, although it will exhibit chlorosis in alkaline soils.

Several cultivars are offered for form, dwarf size, foliage color, and improved hardiness.

Forget-me-nots reseed abundantly to perform year after year. Its tiny blue, pink, or white flowers bloom generously on delicate. multibranched stems 6 to 12 inches tall.

Forget-me-nots prefer fertile, moist, well-drained soil that is rich in organic matter, and perform well in wet soil. They prefer light shade, but will tolerate full sun. Water and feed them liberally. They do best in regions with long, cool springs. Elsewhere, spring crops will set seeds and die out. Then, after late-summer rains, a second crop will come up to give you fall color.

The outer portion of the petals is sky blue and the inner part pinkish or purplish. Each flower is about an inch long, and they are produced in clusters that hang gracefully at the ends of branching stems. They bloom in April and May. All foliage dies back and usually has disappeared by July. Virginia bluebell is restrained in growth and not invasive, but will self-sow here and there.

The plant prefers a cool, moist soil high in organic matter, and is partial to dense shade. It does best in the cool-summer climates of the northern latitudes. Space plants 8 to 12 inches apart.

Mulching will help keep soil cool and moist in the summer and also provide a continual supply of decaying organic matter. Keep the soil evenly moist but never soggy. Do not remove the foliage when it starts to degenerate, but allow it to die down naturally, as with bulbs.

This fern thrives in areas with light shade, but can tolerate alternate sunlight if the soil is kept moist. The ostrich fern is easy to grow, but because of its height, it is most effectively used as a background plant. Plants should be set 3 feet apart to allow room for spreading.