This section is from the book "Flower Gardening", by H. S. Adams. Also available from Amazon: Flower gardening.
For intense blue in March the Siberian squill (Scilia sibirica) is unrivalled unless it is by the early S. bifolia of the Taurus mountains. These two, which have white varieties, are the most desirable of the very low scilla species that are usually called squills. The taller May-flowering species are distinguished as wood hyacinths, though the English one (S. nutans) is better known as bluebells. This is a little more than a foot high and very handsome in the garden, as are also the taller Spanish wood hyacinth (S. Hispánica, or catnpanu-lata) and S. patula. Of the first two there are white and pink variations, but the blue type is preferable to them.
The "glory-of-the-snow" (Chionodoxa), which has delicate blue star blossoms with a white center, is another inexpensive bulb that sadly needs recognition of its charms. It blooms in March and masses beautifully. There are several species; the one generally planted is C. Luciliae, which now has pink and white varieties.
Snowdrops would be worth planting for possible February bloom even if their little white bells were not a welcome sight at any time. The old snowdrop (Galanthus nivalis) has a double form that may appeal to some; but it is inferior to the single, and neither is the equal of the giant snowdrop (G. Elwesii) for garden effect. The Crimean snowdrop (G. plicatus) is another tall species, and there are half a dozen more if these do not offer variety enough. The somewhat similar spring snowflake (Leucojum vernum) and summer snow-flake (L. aestivum), the one blooming in April and the other in May, are hardly less useful.
Other thoroughly reliable spring bulbs are the spring star flower (Triteleia uniflora), which has deliriously fragrant bluish white blossoms; the Indian quamash (Camassia escalenta) with tall spikes of blue blossoms; the golden garlic (Allium Moly), which is about the last of the spring bulbs to bloom, and Pushkinia libanotica. The best star-of-Beth-lehem (Orniihogallum arabicum), the firecracker plant (Brodiaea coccinea), the netted iris (L reticulata) and the "hardy gloxinia" (Incarvillea Delavayi) are fairly hardy in the North, with protection.
Winter aconite (Eranthis hyemails) responds less readily to culture in the North than any of the bulbs mentioned—none of which calls for any favoring other than as stated in a few instances.
Sometimes there is a moist place in a garden under a shrub; there, perhaps, the green foliage tufts and yellow blossoms will show themselves in March or April. The bulbs are cheap.
With coddling still more spring bulbs are possibilities in the North, but are materially less risky propositions to the southward. Several of the windflowers that are so beautiful in England every spring, such as Anemone coronaria, A. fulgens, A. St. Brigid, A. hortensis, A. blanda, A. apennina and A. nemorosa Robinsoniana, are among these— so are Gladiolus Colvillei, the early species that is forced in quantities; the little known but very beautiful deep blue Ixiolirion tataricum, the showy red amaryllis-like Habranthus pratensis and the gorgeous single and double forms of Asiatic ranunculi. Here is a list that ought to be drawn on more in the nearer South.
All of the spring bulbs, of course, are planted the preceding autumn—generally in October. Only the tulip, hyacinth, narcissus and crocus are very well adapted for general formal planting. For such planting place hyacinths six inches apart, tulips, four, daffodils three and the crocus and other small bulbs two. But with any spring bulb the most satisfactory planting is informal. Use clumps and drifts and aim for effects with a few good varieties, so far as the garden proper is concerned. Other varieties may be colonized here and there in the shrubberies. Combine a May tulip with a perennial rather than with another variety so as to secure marked form as well as color contrast.
Small or large clumps of tulips (selfs), hyacinths, narcissus, and almost any of the little bulbs are very effective when scattered irregularly through the hardy garden. Use the imposing crown imperial only when it can be insured permanency of location; it dislikes being disturbed. The little bulbs, however, are best colonized under deciduous shrubs—where a great many kinds can be grown in unutilized space and left to themselves for years. Some of them, especially scillas, spread rapidly by self-sown seed. If there is a stretch of thin grass that is not cut very early, naturalize some of the bulbs; single trumpet daffodils, Tu-lipa sylvestris, May-blooming tulips (selfs), grape hyacinths, snowdrops, scillas, guinea-hen flower and crocus are all willing subjects.
Summer flowers from bulbs that withstand the northern winter in the open ground are largely the contribution of the lilies. These are the most glorious of summer bulbs and fortunately the reliable species are sufficiently numerous to provide bloom from early June into September. The orange lily (Lilium croceum), the madonna lily (L. candidum), the tiger lily (L. tigrinum), the handsome lily (L. speciosum) and the gold-banded lily (L. aura turn) are very hardy, though the last requires frequent renewal, and will carry the season through. All told, there are nearly thirty hardy species from which to make a selection.
Two of the bulbous irises would do more if they had the chance. Abroad there are myriads of the Spanish iris (7. hispánica) and the English iris (I. anglica) in the early summer gardens but in the United States, despite their cheapness, they make scant headway. The bulbs are planted like tulips and require no more care. Named varieties of the Spanish iris are only one dollar a hundred; mass the selfs, like Belle Chinoise, King of the Blues and British Queen. The larger and later English iris is similar, but lacks yellow; Othello and Mont Blanc are good selfs.
Dahlias and cannas, which are tuberous, and the large-flowered gladioli loom up more prominently in the summer garden. All have unquestioned value there, though they are not very plastic material. They would be of more value if the rule was to plant them with greater care; they are mixed too much. Try one variety—the yellow Princess Victoria show dahlia, the soft pink Wawa canna or the vermilion Brenchleyensis gladiolus—in a rather bold garden grouping and let there be none other in sight. The effect will be a revelation if you are addicted to the variety habit Or try two varieties harmonized or contrasted; for a striking violet and yellow combination plant the Blue Jay and Sulphur King gladioli side by side.
Two of the most graceful and colorful summer-flowering bulbs, the African corn lily (Ixia) and the monbretia, are nominally hardy with protection—the latter has stood the test well up in New England, but north of Washington it is best to plant the bulbs in the spring and take them up in autumn. Ixias and the closely allied sparaxis have strange color combinations, even seagreen with a black center. Plant by named varieties; a mixture is horrible. Monbretias run the whole gamut of vermilion, orange and yellow shades. These also ought to be planted by named varieties. The new hybrids cost more than the old, but have larger blossoms.
The great white summer-flowering hyacinth (Galtonia, or Hyacinthus, candicans) is treated the same way in the North. Being white, it fits anywhere. Try it with the scarlet Gladiolus Brenchleyensis, or one of the primrose or violet Groff hybrids, instead of using two varieties of gladioli. The height is about three feet, but this is doubled in favorable circumstances.
The white bugle lily (JVatsonia ardernei), from the Cape of Good Hope, resembles a gladiolus but is taller; it is very fine for the garden. The yellow calla (Rich ardi a Elliot tiana), which masses well in appropriate positions; the Chilian lily (AU stromeria chilensis), which is not hardy without protection; the brilliant red Scarborough lily (VaL i lota purpurea), the pink and white fairly lilies ( zephy ranthes) and the tiger flower (Tigridia pavonia) are all desirable tender bulbs.
A few of the summer bulbs are grown in the North only in tubs or pots, which may be sunk in the ground if desired—to give the effect of planting out. The great crinums, C. longifolium (capense), C. Moor ex and C. Powelii and the blue African lily (Agapanthus umbellatus) are conspicuous among these.
The showiest of the autumn-blooming bulbs is the belladonna lily {Amaryllis Belladonna), whose pink and white bloom is superb when planted out in a sheltered, hardy border as it is in England. Here Washington is about the safe northern limit for this treatment. And even there it should have some attention. It should have warmth and be planted deep, but when flowering it is such a desirable addition to the garden that the extra care is of negligible consideration. There is a wide range of shades from white to red and a variety in form and size of the flowers.
Other autumn-blooming bulbs are numerous, but while they are usually hardy few of them are for the many. The saffron crocus (C. sativus) and the blue C. speciosus are easy selections; so are the white meadow saffron (Colchicum autumnale alba) and the lily-of-the-field (Sternbergia lutea). Add, perhaps, one of the hardy cyclamens, C. neapolitanum, as an experiment.
Winter-blooming species of crocus, iris and cyclamen are suitable only for mild climates—even then special care will be necessary.
 
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