142 



HORTICULTUEE 



February 1, 1913 



Red Spider versus Damping Down 



"Lay on, Macduff, 

 And damn'd be him that first cries 'Hold, enough.' " 



Shakespeare. 



The expected has happened. Since the publication 

 of my article on Bed Spider in Horticulture of Jan. 

 4th each successive copy has been scanned with trepida- 

 tion, fearing the coming onslaught. And when the 

 storm broke it came from an unexpected quarter ; my es- 

 teemed colleague George H. Penson has fallen foul of my 

 views. However, I trust that the knowledge that I have 

 entered the lists with such a doughty opponent will so 

 sharpen my wits as to enable me to refute his (for once), 

 fallacious reasoning. 



It is a grand thing in a controversy if you can take 

 your opponent's argument and turn it against himself, 

 "For 'tis the sport to have the enginer hoist with his 

 own petar." Let us carefully examine the instance 

 cited by Mr. Penson to prove that damping down is 

 efficacious in preventing the attack of red spider upon 

 plants. Here it is: In a house where more than half 

 the floor space was open water tanks and where (owing- 

 to evaporation from these tanks and possibly frequent 

 damping of walks, etc.) the atmosphere was probably 

 alwa^vs laden with moisture there was no spider for some 

 months until some was imported into the house on plants 

 of Clerodendron fallax, and before these had finished 

 flowering the- spider had spread to all the other plants in 

 the house. Mr. Penson here generously concedes that 

 moisture will not l-ill spider, but he asserts in a most 

 positive manner that it will prevent it. His theory ap- 

 pears to be, that, providing there is no spider in a given 

 house, then, moisture will prevent its appearance there 

 unless carried in on a plant or otherwise imported. I 

 will go farther than that for I will positively state that 

 if a house of plants be absolutely free from spider or 

 spiders' eggs, and be kept as dry as the sands of the 

 Sahara Desert there will never be one single spider in 

 that house, providing none are imported from without; 

 and every man who does not believe in spontaneous gen- 

 eration of life must support this statement. This being 

 conceded, let us ask what possible effect moisture can 

 have upon red spider. Mr. Penson says moisture will 

 not kill it. He cannot believe it prevents its breeding. 

 for did they not breed so rapidly in his house which was 

 always moist that they covered everything ? It certainly 

 doesn't seem to produce any disease amongst them, for 

 did they not thrive admirably? Nor can it be that the 

 environment was in anyway objectionable because they 

 multiplied and covered every plant. Moisture then ap- 

 pears only to have any effect on spider when the spider 

 is not present, a sort of distant treatment. Why did 

 they neglect to damp the house where the Clerodendrons 

 were previously growing? or was this a strain of spider 

 which had become immune to moisture? Mr. Penson 

 asks why the spider always starts or makes its first ap- 

 pearance on a peach tree right where the foliage touches 

 the pipes or hangs over a main and further says "Take 

 a bench of beans, the dryest end is sure to secure the lead 

 in the spider race." The answer is — Spider usually se- 

 cures a start in a house that has reasonably good care, in 

 those spots which are the most inaccessible to the hose or 

 syringe and where there is sufficient heat for its rapid 

 propagation ; and these conditions are generally found 

 at the back of a bench and near the heating pipe or in a 

 vinery or peach house at the bottom of the tree or vine 



and near the heating pipes. As heated air has a greater 

 capacity for moisture, the chances are that there is a 

 greater amount of atmospheric moisture in these very 

 spots than in the other parts of the house. Pardon the 

 reiteration, but heat favoring rapid propagation, and 

 being out of convenient reach of water applied with 

 force, and with that correct upper cut, is the cause of 

 spider making its appearance in quantity, in those places 

 mentioned by Mr. Penson. 



Educating a Gardener 



Under the above heading Vernon T. Sherwood attacks 

 me for saying things in my article on "Neglected Op- 

 portunities" which I never said. He implies that I said 

 that it was necessary for a gardener to go to college, 

 but while I think it would be a splendid thing if every 

 gardener could take a college course as a part of his 

 training, I merely urged that the young gardener take 

 'advantage of every opportunity of improving his knowl- 

 edge, stating what I thought were some good reasons for 

 doing so. It is no "obsession or fetich" that the man 

 drawing the highest salary that I know of, in our pro- 

 fession, is a college graduate, and there are a lot more 

 holding some of the most desirable positions, to the credit 

 of themselves and the satisfaction of their employers. 

 Quoting Mr. Sherwood he says : — "To my mind the place 

 to learn estate management is on an estate, and a mo- 

 ment's reflection will so obviously convince anyone that 

 this not only applies to our profession, but also to rail- 

 roading, engineering, or any of the other higher call- 

 ings." If Mr. Sherwood instead of taking one moment's 

 reflection will "make it two," he will probably arrive at 

 the conclusion that he is dead wrong, and will be con- 

 vinced that the engineer who learns his profession by 

 working for the local city engineer has not one chance in 

 ten thousand with a graduate of, say the Massachusetts 

 Institute of Technology, nor the doctor who acquires his 

 knowledge (were it possible) by working under some 

 other doctor, have any chance with a graduate of Johns 

 Hopkins University, or any other good medical college 

 and, without citing more instances, the same thing holds 

 good nearly everywhere. And Mr. Sherwood might have 

 taken two moments reflection on the man (or is it super- 

 man) who can tell whether a soil is good or otherwise 

 by "feel and look;" if he had he might not have had 

 quite so fine a contempt for the man who gives or gets 

 the analysis of a soil. I do not blame him a bit for his 

 admiration of the man who can tell the good from the 

 bad soils by "feel and look." Were it my good fortune 

 to meet such a man my admiration would be profound, 

 yea ! almost worship. However, it strikes me that the 

 touch which could discern a lack of lime in a sample of 

 soil would be of a most delicate order, and the X-ray 

 eye that would discover a deficiency of nitrogen in soil 

 would be a valuable accomplishment to its possessor. 

 "Look and touch" can only be a guide to a soil's physical 

 condition and is useless to determine its chemical con- 

 stituents. For that, we must turn to the man with a 

 knowledge of chemistry. And he is mostly a college 

 graduate. 



Lenox, J/ass. 



/^^<^. 



/4*^ 



A CORRECTION— In Edwin Jenlvins' article on "Green- 

 house Heating," in our issue of January 25, the word 

 "maximum" was used instead of "optimum," through no 

 fault of Mr. Jenkins'. The "axiom" should read as follows: 

 Opiimum t einperatures should be maintained. 



