he a friend of trees? Have you not seen trees badly defaced by having their important branches cut off in order to make way for telephone or lighting wires, or to permit an old house to be moved along a street? Is this really necessary? Then there are the bacteria of decay, which get into a tree through a jagged, broken limb, or one that is improperly sawed off, or through an injured place on the trunk, and so cause the tree to rot. Have you seen shade trees treated by "tree surgery": the rotten material cut out; the wound painted with creosote and tar to kill the bacteria ; the cavity filled with cement? In this way the lives of valuable shade trees are lengthened by many years. How are large branches of shade trees prevented from breaking off? There are also insects of many sorts that feed upon some parts of trees, and injure them. Think how attractive the sweet, juicy fruits, the fresh leaves, the nourishing growing layer under the bark, and the tender roots must be to the insects that need these foods for their growth and development. But since man is growing trees for his own use, and not for the insects' use, he must destroy the insects. We shall learn about some of these pests in § 348. Do you know the month and day of Arbor Day? "Arbor means tree, so Arbor Day is really Tree Day. Since trees give us so much pleasure, and supply us with so many useful things, and have to contend with so many enemies, do you not think we ought to plant trees to take the place of those that must soon die or be used up? Arbor Day should be a day not merely for planting trees, but for helping those we already have, so that they may live longer lives and be free from pests and disease. Make a tree census of your block, and tell how many trees need care and help. How many more trees could be planted, without crowding, in the parking of your block? 332. What is a Weed? Do you know what "dirt" is? Some one has said it is "matter out of place." So we may say that a weed is a plant out of place, or where we do not want it to grow. Thus, grass is not a weed on a lawn, but it is a weed in a strawberry patch. The oxeye daisy has beautiful flowers, but it is a pest in a hayfield. What weeds do you know when you see them? Do you know the shepherd's-purse, lamb's-quarters, pigweed, wild mustard, mullein, milkweed, smartweed, cinquefoil (meaning "five leaves "), quack grass, fireweed, and Canada thistle? lion, plantain, and dock? there are, and how hard they are to get rid of! Do you realize that men have been trying to destroy weeds for thousands of years, and that many of our weeds have been successfully fighting for their lives against all man's efforts? Only those that were especially hardy and could take advantage of every opportunity have lived on. No wonder it is hard for us to get rid of them! Weeds choke up canals and irrigation ditches, cover railroad tracks, take moisture and plant foods from our gardens, shade growing garden plants and cut off their sunlight, fasten themselves to other plants, as parasites (see § 195), and rob plants of their sap. Besides doing these things some weeds produce substances that injure our cattle, or give milk or meat a disagreeable taste. How about the sorrel, dande- If the seeds of weeds become mixed with the seeds of the grass and clover which the farmer sows for his hay, they are very hard to get rid of; but in the garden we can usually pull them up or destroy them by hoeing. How can we get rid of dandelions on a lawn? Is it of much use for your neighbor to dig the dandelions out of his lawn, if you let them go to seed in yours? How long a dandelion root have you seen? Does it do much good to break off the top of a dandelion plant? Have you ever tried to pull up the common sorrel? What are its roots like? Cultivating between the rows of plant crops and trees (see § 155) is not only for the purpose of making the top layer of ground powdery, but to destroy weeds. May the cut weeds sometimes be useful as fertilizers of the soil? 333. How Can We Plant for Beauty? Are plants of value to us only because they are useful, or because they also please our sense of the beautiful? Is it not true that we cannot help having a feeling of appreciation and delight when we enter a well-arranged flower garden? We need to learn that a flower garden is not simply a place where flowering plants grow, but that there are ways for arranging the plants to make them appear to the best advantage. A few simple rules will help us (see Fig. 251): (1) A large variety of flowers in a garden is often not nearly so pleasing as a mass of the same flowers, or masses of a very few varieties. (2) When we are putting flowering plants near one another, we should take care to get flowers of colors which harmonize, or look well together. This is especially true of different kinds of flowers in the same bed. Of course, if the flowers bloom at different seasons, as tulips in the spring, asters in the summer, and chrysanthemums in the fall, many combinations can be made. This is often done, and makes an attractive bed all the time. (3) Small plants should be placed outside, or in front of, tall plants or shrubs. Shrubs around foundations of a house hide unsightly bricks or stones, and make the house look as though it belonged where we find it. (4) The lawn should never appear to be dotted with shrubs and flower beds, but a soft expanse of green sod should be left by itself, as it is very pretty. (5) Flower beds around the roots of trees are not artistic. (6) Trees and shrubbery should not be so dense that the view from or to the house is completely shut off. FIG. 251.- - A beautiful lawn. How does it illustrate the rules of "Planting for Beauty"? (7) Shrubs should be trimmed up, so that grass will grow near them, and so that the ground under the shrubs can be cultivated. Shrubbery following a path is very pretty. Terracing, or making the lawn or garden on different levels, whenever it is possible, adds a great deal of beauty to a lawn or garden. Make a map of some lawn in your neighborhood, marking the position of trees and shrubs. How can it be improved? Suggest how you could get both use and beauty out of a back-yard city garden. 334. Can Man Improve upon Nature? Do we want to get "back to nature" in the growing of our food plants? The farmer looks over the ears of corn from his best field, and picks out the most perfect ear to save for his seed corn. He knows from experience that one ear is not so good as another for planting. Luther Burbank and other scientists have realized this also, and have done wonderful things to improve the plants which nature has provided. Men have developed many varieties of plants simply by choosing an individual plant which has the qualities that they desire. Perhaps it is height, or shape, or time of blossoming. For one thing, they take care to see that the plant is self-pollinated, that is, that its pollen comes only from the plant that produces the seed. Then these seeds are planted. Some of the young plants will be like the parent, others will be different. Only those young plants are saved which are like the parent plant. This careful selection is carried on through many generations. Each time only the right plants are saved and used, until finally the variety is developed as we desired it to be. This improving of plants is also carried out by crossbreeding. For instance, wheat that is tall and easily attacked by rusts is "crossed" with wheat which is short and able to resist rusts. This means that the pollen of one variety is used to fertilize the " egg of the other variety. Then only that wheat is saved which is tall and resists rusts. If we select such wheat for many generations, we may develop a variety that rusts cannot injure. By crossbreeding and careful selection, our fleshy fruits (what are they?) have been improved in flavor, size, and other qualities; |