As we use the words in gardening operations, they include any substance, animal or mineral, that will add quantity, weight, vigor and size to our crops. I shall not attempt to give you any learned discourse on chemical manures, because, first, I am not able, and, secondly, you can easily obtain a report from the many state agricultural and horticultural stations giving the analyses of the several manures and the quantities used, as well as their effect on different soils and plants.
The paper read at the Cleveland con-venticn of the S. A. F., in August, 1896, by Prof. R. C. Kedzie, M. A., of the Michigan Agricultural College, was very instructive. He said "Potassium, phosphorus and nitrogen are of the highest importance to florists for four reasons: First, they are absolutely indispensable to vegetable life, because no plant can grow in the absence of any one of them; second, because in available form they are found in smaller amounts than other food elements; third, because they are soonest exhausted by cultivation; fourth, because they are especially concerned in the early growth of plants up to and including the period of flowering." For their great value, not only to the farmer, but to the gardener, the professor called them "The Chemical Tripod in Floriculture."
The fertilizer that is a favorite with all florists is what we call bone dust or flour. There is sometimes confusion about the names of these grades. With us the bone dust is ground up about as fine as Scotch oatmeal, but there are too many coarse pieces in it to be available to the plants in one season. If the plants were to grow two or three years in the same pot or bench, then the coarser particles would be all right, because the coarser particles would be gradually dissolving and giving benefit to the soil and plants; but if not dis-solved, then you have thrown out a costly fertilizer and had no benefit. So when we want " bone" for roses or carnations, or to mix with our potting soil in early spring, to give our soft-wooded plants a jump, we order the bone "flour," which is really as fine as flour.
Bone is the most complete manure we can use, because it contains both phosphate and nitrogen. The quantity you can use is often questioned. I have heard one professor say he "thought you could not overdo it if the soil was not allowed to get dry." We have used on carnations 200 pounds on a bench with five inches of soil, 200 feet long and six feet wide, and seen only the best results. For potting soil we have used a 6-inch pot of bone to an ordinary wheelbarrow of soil. Perhaps much more could be added with safety, but we don't think it advisable.
Phosphates produce flowers and nitrates produce a strong leaf growth, giving a rich green to the foliage. Here it may be as well to say that all manures reach the roots of plants more completely and perfectly when applied in a liquid form than in the dry state, but not all of us have the facilities for so applying them.
Last year, being short of ground bone, we used on carnations in the same quantities as bone a superphosphate of a fine grade that was sold under the name of "potato phosphate," simply being of a better quality than that usually sold to farmers for their wheat, etc.
Nitrate of soda (Chili saltpeter) is valuable for its available nitrogen and we have tried it on several plants, one pound dissolved in fifty gallons of water. It produces a rich growth of leaf and stem, but does not induce flowers (in fact, the contrary), but in the early stages of plants, young roses, for instance, where growth and size of plant are wanted, not flower, it can be used to advantage. My experience with it in mineral form was very disastrous. I sowed it on a bench of carnations and then stirred it in before the carnations were planted, about two pounds on a space 8x7 feet. It killed almost every carnation. A smaller quantity might have had a different effect, but don't use it except in solution. English farmers sow it broadcast on their grain crops in early spring, but on the surface and out of doors is no guide to us. In solution and the proportion named above (one pound in fifty gallons of water) it is a valuable stimulant to violets, producing a larger and deeper blue flower; and as we usually get plenty of violet flowers too often lacking in quality, there is where the nitrate of soda is very valuable.
Prof. Kedzie places a very high value on wood ashes, in fact places them first, and to quote him, he says: "These contain all the mineral matter of plant growth, and so far as minerals are concerned are an all-round manure. Without this mineral matter in some form plants cannot grow." We have many of us a good opportunity to obtain this valuable fertilizer very near home, but do not avail ourselves of it. They can be used with ordinary animal manure. About one peck to a yard or load of soil will be found a safe quantity. As the ashes of wood contain the elements that the mature plant contained, they must furnish the elements for a full and rapid growth.
The way we use our chemical fertilizers is not similar to that followed on the farm or market garden, where a change of manure may be desirable on any one piece of ground. With a bench of roses or carnations it is a new lot of plants and new soil every year, and if bone meal is a perfect manure there can be no harm in using it year after year.
Guano was largely in use thirty years ago when the supply was greater. It is the excrement of sea birds, found on the islands off the coast of Peru. It is difficult now to obtain and what would be sold to you for Peruvian guano would be most likely an imitation. The pure guano was one of the most wonderful of manures. We have used a 2-inch pot of guano in four gallons of water and the effect of an occasional watering on soft-wooded plants was marvelous. If procurable it would, however, be too expensive and not as complete a manure as bone meal.
Of the animal manures the one mostly in use by florists is that of the cow stable. Why, I do not know, as horse manure is richer in ammonia. One of the best rose growers we know, on being asked what manure he used, answered, "Any I can get." A few years ago my neighbor, Mr. W. J. Palmer, showed me two houses of Daybreak carnations that were for general vigor, stout stem and large flowers much superior to other houses ox the same variety. On being asked to account for it, Mr. Palmer said he could not, except that the best lot had manure from his horse stable, while the poorer ones had only cow manure. We believe that the cause was explained.
While certain animal manures may have special fertilizing properties, for our crops of roses and carnations it would be perfectly safe, and I believe beneficial, to use them mixed. There is no doubt there is a difference in the qualities of manure by the difference in the food of the animals. Animal or farm-yard manure should not be allowed to lie in a great heap and violently ferment, or much of its value will be destroyed.
With our roses there is a difference of opinion as to quantity to use. Too much manure in the soil for carnations produces a rank, soft growth, and if bone meal or superphosphate is used a tenth of animal manure is sufficient. With roses a sixth or seventh is sometimes used, and more often less. Sheep manure is much stronger and a twentieth is as strong as it should be used. In making up our compost pile in the summer time for use in the following winter and spring we have often added a fourth of horse or cow manure, and when chopped down and thoroughly mixed with soil it was not more than was beneficial to our usual run of soft-wooded plants, such as geraniums, coleuses, cannas, etc.
There is not any doubt that our animal manures, besides imparting fertilizing properties to the soil, are often of a mechanical benefit, making the soil more porous and friable.
We should remember, in discussing the quantities and qualities of manures, that there is such a wide difference, not only in the chemical properties of soils in different localities, but in the condition of soils of the same qualities. A meadow that has been used as a pasture for ten or fifteen years will give you a sod that must be rich in plant food over that which has been laid down but two years, and previously was cropped year after year. Or again, the soil of a market garden that has annually received a heavy dressing of manure will grow any of our greenhouse crops, while a worn-out garden however good naturally the texture of the soil, will grow nothing without the aid of some quick acting fertilizer.
In concluding this chapter I would remind you that soot (bituminous only) is very largely used by the plant growers of Europe, and Nicholson says: "It has the advantage over other manures that it can hardly be misapplied." No soot is wasted in the cities of Great Britain; it is all sold to the farmer and gardener. It is not, however, a flower producer, but adds size and lustre to the leaf and flower. It is used by all cyclamen growers, mixed with the soil, and as a liquid. And by chrysanthemum growers it is highly valued. A peck of it is put into a bag and placed in fifty gallons of water, and the effect on the leaf and color of the flower is most marked.
Animal or organic manures can be misapplied or used to excess in the greenhouse, but in the field seldom are, and it is generally a sign of a thrifty florist or gardener when you see his place adorned with manure piles; it is money well laid out; it is an investment that with ordinary management is sure to come back with great interest. Millions of acres in our eastern states are crying for manure to replace the properties of the soil that lazy and careless tillage has year after year taken from it.