for July. 1920 



253 



the implement cannot reach. In cold, wet seasons, weeds will 

 generally appear before the crop seeds we have sown, and if 

 they are allowed to persist for any length of time will materially 

 retard the growth of the plants we desire. Hand-weeding along 

 the rows, &c., shonld therefore be commenced as soon as the 

 weeds are large enough to take hold of by the finger and 

 thumb. To facilitate this, should the crop seeds not have com- 

 pletely germinated, the rows should have been correctly marked at 

 each end at sowing time so that if hand weeding is necessary 

 before the crop comes up, a line can be stretched along them. 

 This line would also be of assistance in cultivating between the 

 rows without waiting for the sown seeds to appear. Hand- 

 weeding is best done soon after rain while the soil is soft 

 and moist, and before the ground between the rows is dealt 

 with ; when the ground is in that condition we can pull out 

 weeds without disturbing plants. 



The control and eradication of perennial weeds, or root-weeds 

 as they are sometimes called, presents a somewhat different 

 problem. Although these may of course arise from seed there 

 is no excuse for their continued existence in a mature state in 

 a garden, as it takes several months for seedlings of these to 

 make much underground growth, and several years to reach 

 the large tufts and masses which are sometimes seen. The 

 gardener is not, however, responsible for these weeds when 

 he takes over a legacy of past neglect, or has to make a new 

 garden upon land already infested with them. 



Quite often these perennial weeds are not only kept in the 

 garden but encouraged to spread by the method pursued in 

 handling the soil. It would appear to be a foregone conclusion 

 that weeds which spread by their roots must increase rather 

 than diminish by the practice of breaking up the tufts or 

 pieces of the roots and turning them under during the operation 

 of spading. In carrying out the latter the operator should have 

 a basket or some container with him in which he should ptit 

 every piece of the roots of these weeds he comes across. If this 

 is always done carefully it will not be long before the soil 

 can be entirely cleared from them. Thoroughness in the removal 

 of the roots of perennial weeds is of the utmost importance if 

 we desire to eradicate them, and it is better to confine one's 

 efforts to a portion of the garden at a time and finish it, rather 

 than to only half clean the whole, as the latter method does 

 not forward any. Spading-under these root-weeds only hides 

 them from sight temporarily, and they will soon reappear stronger 

 than ever. 



Cleaning the ground thoroughly is of special importance before 

 planting perennial things such as shrubs, herbaceous plants, ber- 

 ries, bush fruits, asparagus, and such like. If the smallest part 

 of the roots of these weeds is allowed to remain it will not be 

 long before the roots of the plants will become intermingled 

 with a mass of the roots of the weeds and their separation 

 becomes impossible. Almost all the perennial things above men- 

 tioned will, if properly planted and cared for afterwards remain 

 in a flourishing condition for a person's lifetime, it appears there- 

 fore to be an extremely wasteful policy to plant them in foul 

 soil with the certainty that in most cases they will be smothered 

 out by weeds in a few years. 



If we prevent absolutely any top growth arising from these 

 perennial weeds, their roots will sooner or later die. While the 

 top growth of any plant cannot go on unless it has roots, the 

 latter cannot live for any length of time without top growth 

 to support them. althou.gh the roots are generally the more 

 tenacious of life. Therefore if we do not allow any growth 

 from these root-weeds to appear at all, they will sooner or 

 later die. In this connection it must be borne in mind that 

 if top growth is allowed to persist only for a day, the roots 

 will have, even during that short period, received new life. 



.An effective method of destroying root-weeds without much 

 labor, is to cover the entire ground with builder's tar paiUT. 

 weighting it down with earth, stones, or anything that will keep 

 it in its place, taking care that there is sufficient to overlap 

 to prevent light from entering or the weeds growing through, 

 between the strips. Tliis would require to remain in position for 

 two or three months during the growing season. Before placing 

 the paper in position the weeds should be cut off close to the 

 ground. 



A problem of another character is presented by a weedy lawn. 

 Here, too, its existence is the result of bad work when the lawn 

 was made, of subsequent neglect, or of both. 



In making a lawn, while some antiual weeds will invariably 

 appear which subsequent mowing will readicate, perennial weeds 

 should l)e thoroughly cleaned out before sowing the lawn seed. 

 If the latter is of the best quality it will contain no weed seeds, 

 and the subsequent appearance of perennial lawn weeds, like 

 plantain and dandelion, will have lieen caused by seeds of them 

 coming in afterwards. If the ground has l)een well enriched 

 and entirely covered with a thick stand of lawn grass there will 

 be no weak or bare places upon which these weeds can get a 

 foothold. 



Plantain can be killed by cutting it off just below the surface 

 of the ground, but dandelion should have the whole of its root 

 removed. Neither of these weeds spread by their roots so 

 each plant arists from seed. In thick strong grass, seeds are 

 not likely to germinate. Places from which these weeds have 

 been removed should have some fertilizer — sheep manure is 

 good — applied and lawn seed sown upon them. This is best 

 done in early Spring or Fall. Lawns which have been properly 

 made, well fertilized each year, and cut with sufticient frequency, 

 are rarely troubled with weeds, as the strong growth of the 

 grass will prevent them from coming into existence. 



Preparations for killing plantain and dandelion on lawns with- 

 out killing the grass are sold, their active ingredients being sul- 

 phate of iron and sulphate of copper. The reason why these 

 weeds are killed and not the grass is because they have broad 

 leaves lying close and flat to the soil, the powder covering 

 them and also falling into the hearts of the weeds ; while it 

 does not remain upon the grass by reason of its narrow leaves 

 and upright growth, except to a very limited extent, and the 

 slight browning effect of the powder upon them is soon recovered 

 from. 



One of the most pernicious weeds upon lawns, especially of 

 recent years, is Crab Grass, {Synthcrisma sanguiitale), an annual 

 which produces its seed in great volume and so close to the 

 ground that the lawn mower cannot reach it. Further, is spreads 

 by rooting at the joints, and upon weak and badly cared for 

 lawns will soon entirely kill out the lawn grass. Prevention 

 is attained by the means noted above for other weeds. When it 

 exists, removing it by raking it out thoroughly and continuously 

 with a sharp iron rake, adding lawn seed and fertilizer as the 

 work proceeds, is the best way of controlling it. 



One cannot emphasize too strongly the fact that the remedy 

 for all lawn weeds is to secure a strong growth of lawn plants 

 so that they can be victorious in their struggle for existence 

 against the weeds. 



Weeds upon walks are best controlled liy the use of some 

 reliable arsenical herbicide which, if thoroughly applied under 

 right conditions according to directions sent out, will keep walks 

 free from weeds during the entire season. 



Obviously our remarks apply to gardens. While the under- 

 lying principles of weed control are the same in connection 

 with farming and truck growing, their application will naturally 

 differ ; which differences space will not now permit us to discuss. 

 In any case the loss and bad effects of allowing weeds to exist 

 are the same. As regards farming, an expert of the United 

 States Department of Agriculture has recently written : "It is 

 difficult to estimate the damage wrought by weeds, but it is 

 probable that they directly cost the American farmers several 

 hundred million dollars every year." 



In common with many other bad things, weeds are not an en- 

 tirely unmi.xed evil. Bailey has stated, "It wottld have been a 

 sorry thing for agriculture if there had been no weeds. They 

 have made us stir the soil, and stirring the soil is the foundation 

 of good crops. Even after we have learned that crops are 

 benefited by the stirring of the land, we are likely to forget the 

 lesson, or to be neglectful of it unless the weeds constantly 

 remind us of it." 



It is not uncommon to hear the expression, "I see my garden 

 is getting weedy, I must get the hoe busy," the inference from 

 this remark being that if there were no weeds the hoe wottld 

 not be used. If the liest results are looked for the necessity 

 for continual cultivation between plants is just as great whether 

 weeds exist or not. 



Constant surface cultivation promotes soil ventilation. The 

 soil needs ventilation. The roots of growing plants and the 

 decomposition of organic matter in the soil tend to constantly 

 exhaust the latter of its free oxygen and to replace this by 

 carbonic acid which is not used by the roots, althou.gh it is 

 by the leaves. Hence without some interchange of air between 

 the contents of the soil cavities and the atmosphere above, the 

 roots are retarded in their growth, and if this interchange is 

 entirely prevented for any considerable length of time, the 

 roots sooner or later become smothered and perish. In a suffi- 

 ciently porous soil, changes in temperature and in atmospheric 

 pressure, aided by wind and rain, furnish the needed soil ven- 

 tilation, but in poorly-drained soils and in soils not thoroughly 

 and frequently stirred, the roots of plants often suffer from 

 insufficient oxygen. Therefore, we should never allow the 

 existence of a puddled crust upon the surface, due to the com- 

 pacting influence of rain, to remain any longer than possible. 

 The best practice calls for crop cultivation after every rain. 



Then a.gain, one of the requirements for nitrification is an 

 adequate sup|)ly of oxygen. The nitrifying organisms require 

 oxy.gcn for their existence, therefore in the entire absence of 

 o.xygen nitrification cannot go on, and also, therefore, the 

 formation of a hard crust upon the surface of the ground check.'' 

 nitrification. 



(Continued on page 258) 



