The soil should never be permitted to become baked. After a hard rain, when the surface has been beaten down, it should be loosened as soon as it is dry enough to work, and should be kept loosened. This is one of the most important points in the cultivation of the rose.
During this cultivation, and at all convenient times; keep a sharp lookout for suckers, which, as described in the previous part, are growths shooting up from the understock below the bud graft.
A little critical study of the rose plant will enable any thoughtful person to distinguish these undesired growths, which as previously noted are beside the main stem, and are always, whether the understock be Brier, Manetti, Multiflora, Ragged Robin, or Madame Plantier, markedly different from the normal appearance of the Tea or Hybrid Tea rose. Usually the understock produces leaves with seven leaflets and of different colour.
The suckers should be carefully broken off at their point of junction with the root, if this can be done without disturbing the plant. Otherwise they should be cut off as low in the ground as the shears will reach. If this detail is neglected the result may be a flourishing group of shoots from the under-stock, not disposed to bloom at all, and so absorbing the root energy as to cause the budded variety to languish, and eventually to die, leaving an undesirable "wild" rose.
As soon as the flower buds begin to form about half a gallon of weak liquid manure should be poured around each plant weekly as long as the plant continues to bloom. A good time to apply this is just before a rain, as it will thus be washed down to the tender feeding roots and eagerly appropriated.
The liquid manure should not be too strong. "Weak and often" is the gardener's motto. Half a bushel of cow manure to a barrel of water is about the proper strength. The liquids collected from the barn and stable, diluted to the colour of ginger ale, may be used in the same quantities.
Frequent syringing with clean water, or spraying with a hose, when that is accessible, will do much to keep the leaves in a healthy condition. This is especially necessary near a large city, a factory, or a railway where soft coal is burned. The floating particles lodging on the leaves fill up the pores, which are the lungs of the plant, and unless the foliage is kept clean the plant will speedily sicken and the leaves drop prematurely.
In extreme cases in towns it is necessary to sponge the leaves in order to open the pores, but frequent syringing under ordinary circumstances will be sufficient. The frequent showering with water will also keep insect pests in check, especially aphis and red spider.
Cut the flowers for more bloom
When the roses are in bloom, be generous to your friends. Cut as many as possible each day. On the plant they soon attain their full development and fall away. They endure longer when cut and put into water indoors. Cut in the early morning before the flowers are fully open. It is better for the plant to have the flowers picked as freely as possible, and with as long stems as the growth will permit, merely observing the precaution of leaving an outward-growing eye, or perhaps two for safety, on the stem below the cut.
Where it has been found impossible to pick all the roses for use, then the plants should be gone over daily and all faded flowers removed to a point at least two eyes below the flowers. A regular practice of this precaution is the only means of insuring some autumnal bloom from the Hybrid Perpetuals.
For large flowers, disbud freely on all free bloomers and a very much finer effect will be obtained than if the plant be permitted to try to mature all the buds that it forms.
Some varieties form large clusters of buds at the terminal point of the leading shoots, and if all these buds are allowed to remain the vigour of the plant is distributed among the group, so that the best results cannot be obtained unless one is striving for general effect. If fine single specimens are desired, the best bud only should be retained and all the others removed as soon as they can be pinched off. The centre bud is usually the strongest, but as it may possibly be malformed, the most promising bud should be selected.
Many rose-lovers will prefer the profusion of flowers given by the June bloom-burst of the Hybrid Perpetuals.
Save for the production of exhibition blooms, the Teas and Hybrid Teas give a quite satisfactory result without disbudding, but the quality of bloom within a season is considerably increased if, as previously suggested, the flowers are constantly cut with liberal stems.
No disbudding need be considered for the various climbing roses, or for the Rugosas, Polyanthas, Hybrid Brier, and "species" roses.
Since roses do best in comparatively cool and moist soil, a summer mulch is beneficial. Because of its tendency to harbour the "black-spot" organisms, a manure mulch is no longer found advisable. Peat-moss is a most effective mulch material, retaining moisture, keeping down weeds, and maintaining protection from the sun.
Tobacco stems, the refuse from cigar manufacture, either as baled for sale or ground into a convenient texture, provide an excellent mulch material, serving not only to retain moisture but to prevent the ravages of the aphis, and when spent and worked into the soil, give a distinct fertilizing value.
The "dust mulch," resulting from finely pulverized top soil, is also effective, and it costs only a little "elbow grease." One grower who carefully saves all leaves and vegetable waste for a compost heap finds the resulting leaf soil a good mulch and an excellent fertilizer.
The "Rose-Zone Map," prepared for the American Rose Society by the Federal Bureau of Plant Industry, and first published in the American Rose Annual for 1920, outlines four regions in the United States, in the first and southernmost of which even tender Tea roses are hardy outdoors without any protection. Much of California, part of Arizona, most of Texas, Louisiana, Arkansas, Mississippi, Alabama, Georgia, and South Carolina, and all of Florida, are in this zone.
The second zone runs from New Mexico east in an irregular line above the first zone, touching Colorado, Kansas, Missouri, southern Iowa, Illinois, Indiana, Kentucky, Tennessee, North Carolina, West Virginia, Maryland, and Delaware, within which territory Hybrid Tea roses are considered safe without protection.
North to the Great Lakes, the New England and middle western and north-western states is the region in which the Hybrid Perpetuals are expected to endure without protection.
The zone in which only the wild roses indigenous to the neighbourhood may be expected to survive includes the high regions and the dry regions.
Any rose is hardy anywhere if sufficiently protected, a fact which needs to be impressed on present and prospective rose-growers. It is not difficult for the amateur to determine the protection required for his roses in these days of widely accessible and accurate weather reports.
Generally speaking, roses suffer winter damage less from cold than from exposure to alternations of high winds and warm sunshine. Good protection, in all but the regions which have zero-minus temperatures for long periods, is in keeping off the wind and the sunshine rather than in close and sometimes smothering coverings.
In the second zone above mentioned the tender Tea roses can be wintered, save in locations particularly high or exposed, by a protection of evergreen boughs, salt hay, the heavy grasses, or cornstalks, and in the northern or higher parts of this region both Hybrid Teas and Teas and Polyanthas ought to have this sort of protection.
In the third zone, where the Hybrid Perpetuals and the Rugosas are presumably hardy in the open, they are, especially in the northern and more exposed portions, better for the same treatment.
In this zone the Hybrid Teas require more protection, such as is given, for example, in the rose-loving "Finger Lake" region of New York, by either bending over and tying down the canes under a covering of burlap, heavy stakes preventing breakage by snow, or by a framed covering of boards close enough to shed rain on top. Or in the same region roses are carried over by covering them with earth, ample drainage being provided to prevent wet freezing.
For reasons previously given manure is now thought to be a dubious protection, and reports of the rotting off of roses about which it has heated are frequent. Leaves, applied dry after the ground is frozen, and held in place by boards or other covering that will shed water, are serviceable anywhere, but only as kept dry as aforesaid.
Care must be used not to apply protection until the ground is frozen, to bend down and tie or otherwise secure long canes, and to avoid material that will harbour and feed field mice.
In the region of the Great Lakes, the Hardy Climbing roses need protection by laying them down for an earth covering, in turn protected against excess moisture by boards to shed rain.
Fertilizers for roses
The rose is a strong feeder and must not be neglected. Each year the beds should receive a dressing of manure. Indeed, animal manure, from one to two years old, is, where it can be obtained, the most desirable of foods for the rose beds. Cow manure is generally preferred, as it can be used most liberally without any danger from burning.
Horse manure, when new, is very heating and should not be used while in this condition, not even as a winter mulch. Hog, sheep, and chicken manures are also very useful, but the last two should, however, be used sparingly.
Of the commercial fertilizers, ground bone is the most useful. This may be obtained in several degrees of fineness and is often given in a mixture of grades—fine bonemeal, medium ground bone, and coarse crushed bone in equal parts. This may be used separately or to supplement animal manures. After the beds are well dug, scatter the bone on the surface until the ground is nearly covered; then, with the use of a fork, it can be quickly and thoroughly mixed into the already fine soil.
Nitrate of soda is one of the very best fertilizing agents we can employ if it is given early in the season and supplemented by bone later. It should be scattered thinly (say, about a tablespoonful to a plant) on the surface of the beds about every five weeks during the growing season, being then "watered in."
Emphasis is here laid on the necessity for digging in the animal manures when they are applied. Never should they be used save as thoroughly rotted and broken down, and then lightly forked in.
Rose-lovers are finding it increasingly difficult to obtain animal manures in these days of automobiles. The commercial sheep manure, dried and pulverized, is an excellent substitute, particularly as used with an equal quantity of ground bone or bonemeal. If the grower has access to any form of clean vegetable humus, either as sieved from his own muck pile or as purchased, a very satisfactory mixture can be made by adding this material in double the amount of the "sheep and bone." A liberal trowelful or two, stirred in around each plant at least three times in the season, will do good work.
Recently the value has been urged of phosphoric acid for rose fertilization. Bonemeal adds this, but "basic slag," a remainder of iron-and steel-making, also supplies it in an available form, adding lime as well, and both, with other substances, stimulating the production of certain beneficial soil bacteria. This basic slag may be applied at the rate of a handful to a plant. It is said to aid particularly in producing fragrance in roses.
Dry wood-ashes is a desirable fertilizer and soil-sweetener for roses, its potash content being also of much value. A scant trowelful to a plant, between applications of" sheep and bone," will be right.
Propagation of roses
Many methods are employed in propagating roses, but the practice here described commends itself to the amateur because it is simple and effective. Cuttings can be rooted in the garden or in the greenhouse. For out-of-door work they should be made in November, before severe frost, of wood of the current year's growth.
They should be cut into lengths of six inches, tied into bundles with tarred rope and buried in sandy soil eighteen inches deep, and furthermore protected from freezing by a covering of leaves. In spring, when the ground is thawed and settled, they should be planted in V-shaped trenches in well-prepared beds, using a little rotted barnyard manure.
The cuttings should stand nearly erect and be so deeply planted that only one bud shows above the surface of the ground, two inches apart in the row, with the rows twelve inches apart. In this way many of the fine modern Multiflora and Wichuraiana hardy climbers can be multiplied, as well as many of the "species" roses now coming to be used in the shrubbery.
It must be admitted, however, that some of these latter are difficult to propagate, especially the lovely Rosa Hugonis, one of the very best for the hardy shrub border, with its abundant yellow flowers, but this rose grows readily from seed.
When they are grown under glass the same varieties will give a larger percentage of rooted plants if the cuttings are made two or three inches long, planted in pure sand, in pots or boxes, and kept in a greenhouse in a temperature of 45° F. These cuttings also should be made in autumn, before severe weather, of wood just completing its growth.
They should be planted thickly, about one half their length deep, and well shaded for three weeks. Keep the temperature so low that the buds will not start into growth before a callus is formed or the cutting is rooted. The young plants can be set out in May or early June, either directly from the cutting bed or after having been established in pots.