340 



THE 



GARDENERS' MAGAZINE, 



April 27, 1912, 



inserted, and I then suggested the steady 

 giowth of stock as a great factor to this 

 end. So far as our own buds are con- 

 cerned, they never looked more promising, 

 and we are surely safe from severe frasts 

 now. Young growtli, however, will have 



nmch to pass through yet, unless we have 

 an abnormal spring. 



Late in winter or early in spring is the 

 tune we find most suitable for planting 

 stocks made up from cuttings, such as the 

 Manetti, briar, De la Grifferaie, and poly- 

 antha stocks. To plant these in the autumn 

 means full exposure through the wnnter 

 of the bark that has been under- 

 ground during the previous winter and 

 summer. This is, therefore, rather soft and 

 tender, and I prefer not to expose it un- 

 necessarily early. In the case of seeflling 

 briars we run no such risks because the 

 crown of these has been exposed from the 

 first. It is well to give a little considera- 

 tion to distance when planting stocks, and 

 this depends very much upon the variety 

 to be worked. If dwarf growers of a habit 

 STich as Killarney, Madame Abel Chatenay, 

 and Lady Ashtown, the stocks will be at 

 a suitable distance if planted nine inches 

 apart in the row, and the rows two feet 

 from each other. But with those of 

 stronger growth, Lady Waterlow, Gustave 

 Regis, and Gruss an Teplitz, for example, 

 we must give a little more room. One 

 foot from stock to stock, and the rows 

 two and a-half feet apart, will be found 

 suitable. Extra strong growers should be 

 worked upon stocks fifteen inches apart in 

 the row, and the latter three to three and 

 a-half feet from each other. 



I give these hints because it is a pity 

 to have such wide differences of grovvth, 

 with only one uniform distance allowed 

 for development. It will be found 

 better to work the stocks in small beds, 

 rather than where the plants are to re- 

 main. There is not the same length of 

 untidiness, and it is better to lift and 

 trim off any suckers that may be forming 

 before putting the roses into their per- 

 manent quarters. Nor can one be so sure 

 of a ''take'' as to allow of stocks being 

 in their permanent quarters from the com- 

 mencement. 



I would like to say a word or 

 about the grouping of roses. Too often we 

 find beds and borders containing varieties 

 of such vastly different habit of growth 

 that much of the effect is discounted ; in 

 fact, it is only a muddle, instead of an 

 artistic effect. No doubt tne best 

 effect is gained by one variety in a bed, 

 or, at most, two or three. It is very easy 

 to find these of suitable habit, and of al- 

 most any desire<l colours, among the nume- 

 rous grand bedding roses now available, 

 and a little thought in this direction will 

 be repaid. 



Under glass the roses should now be in 

 full growth and flower, except in^ quite^ 

 cool structures. Careful ventilation and 

 watering has much to do with keeping 

 clear of mildew. 



tain to be in evidence, and I can only once 

 more refer to the necessity for prompt 

 measures against these. The various in- 

 secticides and methods of application hav- 

 ing been so often treated upon I do not 

 propose any additional remarks, except to 

 warn against the use of too powerful solu- 

 tions. This also applies to the use of liquid 

 stimulants, which will be much needed 

 bv roses in pots. So many failures 

 have come to mv knowledge that were un- 

 doubtedly caused by using these too strong, 

 on the supposition that as a little did good 

 more must be l>etter, that I ask no excuse 

 for once more advising a freer use, if you 

 like but do not increase the strength. 



ROSARIAN, 



two 



As usual, insects are cer- 



STREAK, DISEASE IN SWEET 



PEAS--I- 



Much has been written about the cause 



of streak 



in sweet peas, and if printers' 

 ve cured the disease it would 



have long ago ceased to trovible us. 



A high authority says: 

 which the disease is known to-daj 

 lavia basicola — was L>'iven to it 



The name by 



-Thie- 



■was given to it by Zopf 

 in 1876, since when, it has engaged the 

 attention of various scientists, all of whom 

 by various and different methods have 

 arrived at the conclusion that errors of 

 watering and manuring were largely re- 

 sponsible for the existence of the disease 

 wherever it occurred. 



Probably no one cause contributing to 

 the weakening of the root, and thus lay- 

 attack by the fungus, will 

 will fit all cases of disease, 



but there seems no doubt that if care be 



possible check to 



^ streak 



ing it open to 

 l>e found that 



taken to avoid 



Overwater- 



" Whilst 



every 



root development and activity, the 

 d sease' will cease to be so troublesome." 



The same authority says, 

 ing must be avoided at all costs 

 freely admitting that overwatering " 

 would destroy plants, let us rather seek 

 the primary cause of streak disease " in 

 some other direction, for sweet peas grow- 

 ing tmder glass are ordinarily watered daily 

 if necessary, and not infrequently twice a 



and vet there is no appearance of 



g ourselves with the 



to its 



day, 

 streak." 

 Instead of 

 name of the disease, or even as 

 nature^ we may consider the physiology of 

 the plant and its functions. 



The sweet pea belongs to the leguminose 

 family of plants, all of which are naturally 

 supported by nodules on the root contain- 

 ing nitrogen-gathering bacteria, which, in 

 their turn, assimilate the free nitrogen 

 of the atmosphere for the use of the plant. 

 I said naturally, for this function seems 

 to be imperative, as when we unnaturally 

 fee<l any of the leguminous plants mainly 

 on nitrates or nitrogen-containing material, 

 these plants freely feed on the nitrates of 

 the soil, and it appears that nitrogen- 



appears 



gathering bacteria in the root nodules die 

 of inanition ; in fact, an unnatural balance 

 is set up in the economy of the plant, which 

 assumes a parlous condition, susceptible of 

 any and all diseases to which the plant is 

 liable, and death ensues. 



Streak," or any of the fungoid diseases, 

 may be latent, developing when suitable 

 conditions are afforded. 



I do not feel concerned to prove this, for 

 it is sufficient to know that plants of 

 sweet peas remain healthy, and free from 

 " streak " and other diseases, when nitrates 

 and nitrogen-containing materials are not 

 applied to the soil in which the plants 



to be grown. 



It is an establ'Ished fact that the legiimes 

 of our pastures are all destroyed by the 

 too free application of nitrogenous 

 manures, and it is not surprising that the 

 sweet pea should also be susceptible, and 

 succumb to similar treatment. 



Duckwall, in Bacteriological 



The bacteria which 



E. W. 



Technique," says : 

 prove so valuable in fixing the atmospheric 

 nitrogen for the benefit of peas, have a 

 peculiar life history. They are widely dis- 

 tributed in the air, water, and soil, but 

 are frequently absent in some localities, 

 or are so few in numbers as to be of little 

 value to peas grown in such places. When 

 through inoculation, bacteria gam 

 entrance rapid multiplication takes place, 

 so that in a short time the sap is teeming 

 with countless myriads of these tiny organ- 

 isms, which fill up all the channels, multi- 

 plying, until this cycle of their life history 

 is accomplished." 



In a general way, for the healthy growth 

 of sweet peas, most soils require an annual 

 application of phosphates and potash, chalk 

 or lime (ad lib.), with small quantities of 

 magnesia salts, etc., and all these may be 

 applied without being associated with nitro- 

 gen-containing material, such as animal 

 manure and the like. 



A question may naturally arise. If the 

 use of dung and other kinds of organic 

 manure are to be avoided in the growth of 

 sweet peas, how is the necessary supply 

 of humus in the soil to be maintained ? The 

 answer is by manuring the preceding crop 



with organic manures containing nitrogen 

 if this be necessary. ' 



If it should be desirable to grow sweet 

 peas on the same land year after year the 

 supply of humus may be maintained by the 

 application of well-rotted manure, which 

 has been prepared by remaining in a heap 

 for about twelve montlis, for it has been 

 ascertained, that stable manure loses, ap- 

 proximately, 25 per cent, of its nitrogen 

 every three months, and the soil bacteria 

 during the twelve months would have 

 worked up the nitrogen-containing material 

 successively into nitrates, and free nitro- 

 gen, and the latter would by this time have 

 been liberated, and lost in the atmosphere, 

 the residue being mainly organic manure 

 minus nitrogen, 



A question might arise, if nitrogenous 

 manures are not to be used, how are plnnts 

 to be fed and to be made to produce ex- 

 hibition blooms? The answer must be: 

 Wait until the plants become well matured 

 before applying any nitrogen^ then, pos- 

 sibly^ an addition might do ljut little harm, 

 and might be the means of winning the 

 cup, even although it might ultimately in- 

 jure the plants. . 



It does not follow^ that because nitro- 

 gen is absolutely essential to the successful 

 growth of most crops it should be so for 



all plants. 



Nitrogen acts as a poison to sweet peas 

 and all legumes, and the sooner this is re- 

 cognised, and acted upon, the better. — 



Robert Holmes. 



Tuckswood Farm, Old Lakenham. 



RUBUS ARCTICUS. 



This diminutive rubus is not frequentiv 

 found in gardens, probably because it is 

 not always an easy subject to establish, 

 but when once thoroughly at home it proves 

 an exceedingly interesting and attractive 

 plant for the rock garden. This spring it 

 is producing its lovely rose-pink blossoms 



in profusion. . 



It enjoys partial shade, and a colony or 

 it here, that is partly shaded by the over- 

 hanging Prumis prostrata, is growing 

 splendidly. Though perfectly hardy, « 

 practically disappears during wmt«r, ana 

 commences grow-th in the early sprmg. 

 diminutive stems arc never morethan a tew 

 inches high, and its bright green toW 

 makes a fitting setting for the beautitul 

 flowers, while in the autumn the l^a^^ 

 assume a pleasing shade of bronze. 

 A well-drained site should be chosen to 

 sn< l, as M i)osition in the forefront or 

 a r.)cU<M V. tor which it is well suited- - 

 soil in wiiicli i)eat pred<uninatos suits 

 lu'st, an.l in this it thrives, J^^; 

 underground steins, which come up aio 

 the original plant. About the time gro^\ 

 is coiuineiu'ing, a light top-dressing ot 

 simihir to that in which the plant '-"L^ 

 ing can be given with advantage. 



bright summer weather, Kli'''^^'''''''„T„ver 

 serves much benefit from being Y''"??.? V-,.^,, 

 late in the afternoon. If the pl/ntJ-\-^i,, 

 this treatment, and kept u guc- 



its cultivation should be attend^g^^^t^'^ 



cess. 



it 



