The 10,000 cultivars are classified into 3 major groups: they are Nanus, Primulinus and Grandiflorus.

• Hybrids and cultivars in the group of Nanus bloom in early summer with two/three 22 to 35 cm spikes per corm, the spike each bearing 3 to 5 open flowers at a time.

• Those in the group of Primulinus bloom in midsummer with a single very slender 30 to 60 cm stem per corm, the stem bears 20 buds with up to 7 open at a time.

• Cultivars and hybrids from the Grandiflorus group bloom from late spring through autumn with as many as 28 buds on (usually) a single spike of usually 35 to 90 cm tall, dozen of flowers may be open at a time. Gladioli of the Grandiflorus group are classified further by flower size and color in an elaborate trinomial system, with first digit indicating size, the second indicating color and the third intensity of color. The largest Grandiflorus cultivars can get up to 1.7 metre tall, while some miniatures do not reach 90 cm in height.

From the British Gladiolus Society:-

"ALL ABOUT CLASSIFICATION OF GLADIOLUS.

For anyone interested in the Gladiolus, and particularly for those of you interested in attending and competing in Gladiolus classes in shows, you should try and acquaint yourself with the world-wide classification codes. All codes consist of 3 digits, the first of which specifies the diameter of the fully developed bottom floret of the spike, thus:-

The second digit denotes colour (i.e. green, yellow, orange etc, 0-9) and the third digit denotes the "strength" or hue of that colour. Second digits may be (0) = Pale, (2) = Light, (4) = Medium, (6) = Deep and (8) = Very Deep. Notice that the third digits are all even numbers: even numbers indicate that the colour is without any conspicuous markings present, whereas by increasing the number by 1 to make it an odd number signifies that conspicuous markings are present. For example, Doris Darling 442 is a large flowered pale Pink bloom without distinctive markings whereas Pink Elegance 443 is a large flowered pale pink with a distinctive mark, in this case a white throat. The table below indicates how the second and third digits in the classification are used.

So to summarize, all you need to do to become reasonably proficient at recognising Gladiolus codes is to learn the floret width codes (1-5, narrowest to widest) denoted by the first digit (see table above), and below, the second digit COLOUR codes (0-9) and the third digit COLOUR STRENGTH code (0-8). Don't forget that if the third code digit is an odd number it means that the floret has distinctive markings.

This can be followed by:-

• E for Early-Flowering,
• M for Mid-Flowering and/or
• L for Late-Flowering Season.

For Gladiolus in The British Gladiolus Classification System, the following applies:-
"As far as the early, mid and late season bit goes it refers to an average flowering time and is very dependent on the weather and location rather than the flowering months and for the ones we are talking about ie Exhibition types we would not really be wanting blooms before the end of July so the timings below are based on planting made from April through to early June:-

Usually the number of days above from a May planting in the ground the flower will actually open all of its florets but those at the base need to be removed as they die otherwise they may start to set seed pods which will take energy from the florets higher up. Usually its about 14 days from the first floret opening to when the last is out on that flower spike" from Nigel Coe.

For Gladiolus in The North American Gladiolus Council Classification System and in Russia, the following applies:-

from Irina of The First Acquaintance in Russia.

The corms can be started earlier in peat pots in frost-free conditions in a greenhouse before planting outside after the last Spring frost, if you want flowering earlier in the year.

After this the Breeders Name and Year of Introduction, and three numbers (e.g. 8;23;30):-

• which refer to the number of florets which will stay open together (8),
• the number of buds (23) and
• the length of the flower spike in inches (30). This information is only given for exhibition varieties.

Instead of the Fieldheight, which is the normal height used in comparison pages for all other plants, all the Gladioli are compared throughout all the comparison galleries using their Flowerhead size.

Cultivation details are provided in the The British Gladiolus growing page."

and the North Dakota State University with the U.S. Department of Agriculture article.

How to grow Gladioli from article in The Telegraph 15 February 2008 by Sarah Raven:-

"All gladioli are easy to grow. As soon as the soil has warmed up in March or April, plant the corms 20cm (8in) deep; this is deeper than most books will tell you. I use a bulb planter but a long trowel or leek dibber will do. Secured deep in the ground, you are less likely to need a stake. Plant them about 15cm (6in) apart.

If you have bought quite a few, don't plant them all at once. Stagger their planting and you will get a better succession of flowers.

Gladioli need plenty of water to flower well. So, if you can, dig a trench and pile well-rotted manure into the base before planting. This will help feed the bulbs and will also retain water. On well-drained poorer soil, extra watering will be required.

As soon as the flowers appear and until at least three weeks after flowering, apply a high-potash feed (like Tomarite or comfrey juice) every two weeks.

This is essential on poorer soils where flowering will diminish with each successive season.

It's always said you need to lift your gladioli - that, like dahlias, they'll be frosted if left in the ground. It's my fourth year of growing them at Perch Hill and I've never lifted them. I mulch them deeply with 6-7cm (2.5in) of mushroom compost to give them an insulating duvet over their heads in late autumn. You should be safe with this in the south of England and the western fringes of the British Isles, but in colder counties, grow them in a sheltered spot and lift them for the winter when the leaves turn yellow-brown. Lift them and snap the corms from the stems. Dust with sulphur and dry them out for a couple of weeks. Then snap the new corms from the old, discarding the old. The new must be kept dry and cold (but frost-free) until they are replanted.

You can dig and divide the clumps every few years to select the best corms for replanting. Without this, the new cormlets forming will invade the space of the original corm and the nutrients will have to be shared. The risk is lots of foliage and no flower spikes."

Plant Combinations:-

The Extension Bulletin 9 December, 1916 Cornell Extension Bulletin Published by the New York State College of Agriculture at Cornell University, Ithaca, New York Gladiolus Studies - I Botany, History and Evolution of the Gladiolus states:-

"Unless used in masses, the plants are likely to appear rather spindling; but when properly planted, the bed of gladioli is one of the most showy features of summer or autumn.

The beds so used need not be for gladioi exclusively, but may have some annuals or perennials growing with them. Good combinations result from planting early in the spring a bed of white Phlox Drummondii, and later using the gladiolus 'America' between the plants; or pink phlox and the gladiolus 'Rochester White' may be combined. Especially effective is the combination of gladiolus with the summer hyacinth - Galtonia hyacinthiis candicans, the tall spikes of white bloom and the bold foliage of the latter seeming especially harmonious. No better combination is available than that which results from the planting of some corms among irises, which have leaves in perfect harmony with the gladiolus and which bloom in a widely separated season.

The stately spikes are attractive when used in large clumps of one variety among shrubbery. Care must be taken not to place the plants within the detrimental influence of large tree roots or in too much shade.

Gardeners frequently start certain good varieties in boxes or pots, and, when in full growth, transplant them in clumps to places in the border where a bit of color is needed after some other plants have failed.

Miss Andres advocates combining columbines, petunias, and gladioli, not only because of their colors, but also, and mainly, for the excellent succession of bloom provided.

Bold masses of Gladiolus primulinus hybrids are extremely effective, since their various colors blend so well. 'Blue Jay' and 'Baron Joseph Hulot' are violet and blue varieties which harmonize well with yellow varieties, such as 'Golden King' or 'Sulphur King'.

Excellent combinations have been made with roses and gladioli. The June-flowering roses are best for this purpose, since they are entirely out of season when the gladiolus is at its best."

The Extension Bulletin 9 December, 1916 Cornell Extension Bulletin Published by the New York State College of Agriculture at Cornell University, Ithaca, New York Gladiolus Studies - I Botany, History and Evolution of the Gladiolus states:-

DEPTH OF PLANTING DIFFERS WITH THE SOIL TYPE
"The depth of planting will obviously differ with the soil. The lighter the soil, the deeper the corms may be planted. Deep planting is especially successful in dry seasons, because the roots are in cool, moist soil. Usually, with deep planting, staking will be unnecessary. There is danger in deep planting in a heavy, moisture-holding soil. The soil may be too wet and may cause a rotting of the young shoots as well as the corms. If the soil is too clayey the shoots may not have strength enough to emerge, or they may be twisted, and thus made unable to produce a good, strong spike.

It is seen that many of the growers consulted prefer a sandy loam.

E. H. Cushman says that the gladiolus does equally well on any soil, if given the proper culture. The commercial grower, however, who must produce stock at a profit, will choose soil as nearly ideal as possible — in other words, a light loam.

FERTILIZERS AND THEIR USE
Fertilizers applied to plants are valuable in proportion to the amount of the needed plant-food that is available. Only such nutriment as is soluble can be taken into the plant, and therefore much food is locked up, or unavailable. Some fertilizers are applied for their value in unlocking, or freeing, plant-food, rather than for their actual fertilizer value.

The production of gladiolus corms is very analagous to the production of a crop of potatoes. A good standard special potato fertilizer is therefore recommended. Such a fertilizer will be rich in phosphoric acid and potash. The gladiolus is a rank grower and a gross feeder, and responds to any treatment that increases the available plant-food. Either manures or chemicals may be applied as a fertilizer, both of which are valuable in their way. The first kind, stable manure, is of prime importance, but each year it is getting more difficult to obtain this. When possible it is well to use cow, pig, sheep, or poultry manure, rather than that from the horse. It must be borne in mind that sheep manure and poultry manure are especially strong and cannot be applied too abundantly without danger of causing too great vegetative growth, watery corms, or perhaps even a burning of the whole plant. It is thought that the gladiolus is very susceptible to the presence of any manure in contact with its roots. All manure, then, should be thoroughly incorporated with the soil, rather than left in lumps. This is best accomplished by application in the autumn.

All humus-making material produces acidity when rotting in the soil. This can be easily overcome, or neutralized, by the use of lime. B. C. Auten is emphatic in his denunciation of lime. He writes: " Two years' planting upon ground limestone nearly put me out of business." Cooper (1914 c) believes that it will be necessary to use lime "rather freely where heavy applications of stable manure are made or where green manure crops are plowed under, to prevent possible excessive acidity and fungoid or scab diseases."

A method of soil treatment and enrichment is outlined by W. P. Wright substantially as follows in Popular Garden Flowers: In autumn remove the top soil and break up the subsoil, turning in a dressing of three inches of decayed manure. If the ground is very stiff, leaf mold and sand may be added. Leave the surface lumpy. In February, spread on a coat of wood ashes, with an additional quantity of bone flour, at the rate of three ounces per square yard, and fork it in. This operation will simultaneously reduce the lumps to small particles.

H. H. Groff has used the same land for fifteen years, and the only fertilizer he has needed is stable manure and hardwood ashes applied in the autumn before plowing. Hardwood ashes are rich in potash and phosphoric acid as well as in calcium.

B. C. Auten prefers dried blood and steamed bone, with a top-dressing of nitrate of soda and potassium sulfate or muriate. The fertilizer is applied in the seed drill at the bottom of the furrow. Steamed bone and bone meal are to be strongly advocated, since they possess the necessary phosphoric acid and potash.

N. L. Crawford has used an application of five hundred pounds of potassium sulfate per acre at the time of planting, and from three to five hundred pounds more in July or August.

L. M. Gage applies barnyard manure in the fall, and a complete potato fertilizer (4-7-10) in the drills at the time of planting.

S. E. Spencer places a little sheep manure in the furrow at the time of planting, and works a chemical phosphate into the soil when the buds start.

C. W. Brown has used seven cords of manure per acre in the late fall, plowing it under at once to kill the witch grass.

C. Hoeg distributes hardwood ashes at planting, and nitrate of soda two or three times during the growing season.

W. C. Bull, of Ramsgate, England, uses " stable dung dug in during the winter, and superphosphate of lime at the rate of a double handful per square yard, dusted over the surface of the soil immediately after planting."

J. L. Moore uses hen manure and stable manure once in three years. Besides this, he sows a cover crop of rye after the bulbs are dug, and plows under the green growth in the spring.

C. Betscher also seeds rye at the time of the last cultivation, the earlier the better. This he would, no doubt, plow under when in greatest growth and full of sap, for the green crop should not be allowed to get woody, thereby losing its greatest value as a humus maker.

F. C. Thomanh has used, besides sheep manure and hardwood ashes, a great deal of soot. It seems impossible to account for the freedom from disease of his 'Rochester White' gladioli in any other way than by the probability that the soot prohibits the spread of the infection.

Coleman (1914 b) writes: "We make our own fertilizer, so do not have to pay freight on ' filler.' A formula that has given us the best of satisfaction and that the Glads respond to, is represented by 50 per cent sulphate of potash, 25 per cent sulphate of ammonia and 25 per cent nitrate of soda, by weight." This is applied sparingly along the top of the row at planting.

TIME AND MANNER OF PLANTING
In the Northern States of America gladiolus corms may be planted in April or May, according to the season, or they may be kept until July if they do not sprout in their place of storage. They should not be planted until the danger of hard frosts is passed, although a slight frost when the shoots are still below the surface of the soil will not injure them. It is necessary to wait until the soil is somewhat dried, especially with clay soil. A corm naturally begins sending out shoots at the approach of spring, so that if the storage conditions are rather warm the corms must be planted before these growing shoots have exhausted their resources. They must be planted so as to allow the shoots to emerge readily from the soil. The shoots often grow around the corm and are difficult to manage, so that the corms need to be planted properly.

When possible a succession of bloom should be planned, the corms being planted in lots every week or ten days until July. In this way an excellent yield of blooms from a favorite variety may be obtained throughout the season.

Corms that are to be grown for rapid increase in size should be planted as early as possible, so that they may have a longer growing period and make good vegetative growth as well as mature a large corm. Seeds and cormels also need to be planted as early as possible, so that they too may have a long growing season. Soon after the base of the growing stem of the gladiolus has begun to thicken, small corms are found to have formed between the old and the new corm. These are properly called cormels. They are covered with a hard shell, thus differing from seedling gladioli of the same size, which have a covering more like a husk, composed of the dried bases of the previous season's leaves. To keep up the standard of the stock and for rapid propagation, reproduction by cormels is essential. Cormels range from one-sixteenth to three-fourths inch in diameter, and will produce corms of blooming size in a year less time than will seeds. According to the variety, thev flower in from one to four years. A single corm has been known to produce as many as two hundred cormels in a season.

Dombrain (1873) describes a method of planting individual corms for the home garden. With a trowel he digs a hole six or seven inches deep and about five inches across, and fills this hole " with a mixture of sand, powdered charcoal, and light soil in about equal proportions, so that the bulb, when it begins to start and throw out its rootlets, has a light and dry material into which to penetrate, and thus is likely to be saved from rotting, and taking care that the top of the bulb is about four inches beneath the surface." This method, although slow and laborious, might be adaptable in the planting of choice seedlings. Usually, however, for small beds the corms may be planted with a dibber, or the bed may be dug out evenly from a depth of from six to eight inches and the corms put in place and covered evenly.

The commonest commercial method is to plant in rows, the corms being placed a little more than their own diameter apart ; that is, two-inch corms are placed two and one-half or three inches apart. All bulbs over an inch in diameter are placed right side up; others are merely sown in the row as seed. B. F. White recommends setting the corms with the eyes lengthwise of the row. Many of the corms send up two or three flower stems, which will not lean over crosswise of the row as they would if the corms were planted promiscuously, for in the way suggested they help to support one another.

In large plantings the rows are frequently three feet apart. This allows for horse cultivation. The furrows are made with the plow. The fertilizer may be applied at the bottom of the furrow, which is leveled with a hand hoe. Two or three rows of corms are frequently placed in each furrow by bulb growers, since they do about as well as if planted otherwise, and, as Gage suggests, " it is surely much more economical to plant 100,000 bulbs on one acre than the same number using two acres or more."

When planted in single rows, however, the blooms usually become larger, so that for cut-flower or exhibition purposes this method is the better. "

"Immediately on receiving your parcel please open and unpack it. Strip off the outer skin and space the corms out with the buds uppermost. Put them in a clean container such as a seed tray, without any sand or compost under them, and store them uncovered in a cool, dry, frost-free place. Leave them there until you want to break their dormancy as described below.

All corms should be prepared before planting as many will still be dormant when received. The process is similar to chitting potatoes. Peel the outside skin from the corms and stand them somewhere light and warm indoors, e.g. a sunny window-sill. Do not stand them in sand, peat or soil. After a week or two, one or more shoots will emerge around the edge of the basal plate on the bottom of the corm. The corm has now broken dormancy and will grow away successfully. Planting dormant, un-peeled corms may lead to poor, late, or no growth, as will repeated plantings on the same ground and not lifting corms for winter storage. " from Great Western Gladiolus.

Great Western Gladiolus have the following growing guides and Information Sheets:-

"3rd Edition Growing & Showing 7 Part Guide
These notes tell you all you ever wanted to know about growing gladioli well. Even if you don’t exhibit them, you will have much better flowers if you follow these suggestions.

INFORMATION SHEETS
Hybrid Gladioli from Seed
Hybrid Gladioli from Cormlets
Keeping Glads through the Winter
Planting Dates "

Direct access to an individual bulb description page is available:-

• from the list of pages in the Site Map, or
• from clicking on a thumbnail picture in the flower, foliage, form, fruit or garden pictures comparison pages, which has that bulb's name in the text box below it.

These gallery photographs were provided by North American Gladiolus Council.