These old-fashioned favorites are prized for their tubular, often flaring or ruffled blossoms borne in unbranched or branching, usually one-sided spikes in an extremely wide color range. All have sword-shaped leaves. Bloom from spring to fall, depending on kind and time of planting. Superb cut flowers. Good in borders or beds behind mounding plants that cover lower parts of stems, or in large con- tainers with low annuals at base.
Baby gladiolus. Flaring, 212- to 314-in. flowers in short, loose spikes on 112-ft. stems. Flowers are white, pink, red, or lilac; they may be solid or blotched with contrasting color. When left in the ground, will form large clumps in border or among shrubs. Plant in fall or early spring for late spring bloom.
G. communis byzantinus (G. byzantinus). Zones US, MS, LS, CS; USDA 6-9. HARDY GLADIOLUS, BYZANTINE GLADIOLUS. Mainly maroon, sometimes reddish or coppery, 1- to 3-in. flowers in groups of 6 to 12 on 2- to 3-ft. stems. Narrower leaves than garden gladiolus. Plant in early spring for summer bloom. An old Southern favorite. They can be left in the ground.
G. murielae (Acidanthera bicolor). ABYSSINIAN SWORD LILY. Native to Africa. Stems grow 23 ft. tall, bearing 2 to 10 fragrant, creamy white flowers marked chocolate-brown on lower segments. Each blossom is 23 in. wide and 45 in. long. Excellent cut flowers. Plant in spring for bloom in late summer and fall.
Primulinus and butterfly hybrids. These summer bloomers derive in part from an African species with hooded (rather than funnel-shaped), primrose-yellow flowers. Named selections grow 34 ft. tall, each spike carrying up to 18 widely spaced, somewhat hooded blossoms in a wide range of colors. Plants multiply quickly. 'Atom' (sometimes sold as 'Atomic') has brilliant red flowers with a white picotee edge. Blooms of 'Mirella' are reddish orange. Cold-hardy 'Carolina Primrose' blooms are soft yellow with a red-striped throat. 'Boone' is also extra hardy; it has apricot flowers with a yellow throat marked with red.
Group known as butterfly gladiolus has 2- to 3-ft. stems bearing more closely spaced flowers; distinct throat markings or blotches of contrasting color give butterfly appearance. Plant in early spring.
Summer-flowering grandiflora hybrids. GARDEN GLADIOLUS. These complex hybrids are the best-known gladiolus, with the widest color rangewhite, cream, buff, yellow, orange, apricot, salmon, red shades, rose, lavender, purple, smoky shades, even green shades. Individual blooms may be as large as 8 in. across. Stems are 45 ft. tall.
The newer types of garden gladiolus grow to about 5 ft. tall, have sturdier spikes bearing from 12 to 14 open flowers at one time. They are better garden plants than older types and stand upright without staking. Another group, called miniature gladiolus, grows 3 ft. tall, with spikes of 15 to 20 flowers, each 2123 in. wide; useful in garden beds and for cutting.
High-crowned corms, 1122 in. wide, are more productive than older, larger corms (2 in. wide or more). After soil has warmed in spring, plant at 1- to 2-week intervals for 4 to 6 weeks for progression of bloom. Corms bloom 65 to 100 days after planting. Mix plenty of organic compost into the soil before planting. When plants have five leaves, apply complete bulb fertilizer 6 in. from plants and water it in thoroughly. For cut flowers, cut spikes when lowest buds begin to open, leaving a minimum of four leaves on plants to build up corms. If thrips cause whitish streaking on leaves, spray foliage with insecticidal soap or horti- cultural oil.
Plant in rich, well-drained soil. Set corms about four times deeper than their height (plant somewhat shallower in heavy soils). Space big corms 6 in. apart, smaller ones 4 in. apart. Corms can generally be left in the ground from year to year in Middle, Lower, and Coastal South. In the Upper South, dig soon after first frost in autumn. Dry corms on a flat surface in a dark, dry area for 2 to 3 weeks; then store over winter in a single layer in flats or ventilated trays in a cool place (4050F). In the Tropical South, refrigerate corms for a month before planting, then treat as annuals and discard after plant has finished blooming.