September 21. 1907 



HORTICULTURE 



377 



Polygonum Baldschuanicum 



Tliere are few more accommodating climbing plants 

 Hum this Polj'goniim which has now become a firm 

 favorite with all who know of its merits. It is equally 

 at home whether covering a rough, nnsightly fence, an 

 arbor, arch or pergola, yet it is not seen at its best in 

 any of these positions. It is most delightful in the 

 po.oition shown in the accompanying illustration, twin- 

 ing and clambering over some dark leaved tree, prefer- 

 iibly a conifer, as for instance a juniper, Thuya or Picea. 

 When once established it grows with extraordinary 

 rapidity and soon festoons a tree with its slender shoots 

 .and graceful, crcam3'-white flowers. In the photogi-aph 

 the flowers are noticeable chiefly towards the top of the 

 tree for the reason that the Polygojium is planted on 

 the other side where tlie lower part of the tree is cov- 

 ered with its blossom. P. Baldschuanicum flowers in 

 €arly summer and remains in beauty for several weeks. 

 Although it grows most readily when established some 

 find a difficulty in persuading it to make a start. When 

 well rooted all aspects and positions come alike to it, it 

 thrives in them all, but when planting it is wise to 

 choose the coolest and shadiest side of the tree so that 

 the roots may have cool moist soil in which to start. 

 In such a position it quickly gets good root hold and 

 when growing freely finds its way in and out of the 

 brandies in a most delightful way. 



<r^ 7^' 



■'^v. 



<^. .jii---'-i^ 



^-"Ni^"' 



^'^^ 



' -.:^'-% -^ ':/'^^:< 



™^r'-i>J^i^'MWI||!JI ^. 



Season for Tree Pruning 



The theories with regard to this important part of 

 arboriculture have been studied and explained by able 

 practitioners as to the best methods to perform it to 

 insure the future healthy condition of the tree. 



But sufficient consequence as to results is not attached 

 to the season at whicii pruning should he done. 



DeCurs in his admirable work translated by Professor 

 Sargent, states that "a tree can be pruned at any 

 ■season of the year and the best is that when it can be 

 done the cheapest and the most convenient." 



While attaching, and justly, great importance to the 

 method of making necessary amputations, he attaches 

 none whatever ta the season at which this should l)e 

 performed and which is certainly of equal if not para- 

 mount importance. 



It is singular too that this statement is contradicted 

 in another page — where it is admitted that "when prun- 

 ing is done in the autumn sudden and severe fi-osts arc 

 dangerous, and have a tendency to induce decay in 

 freshly made wounds." In the winter "the days are too 

 short and stormy" and "in the spring there is danger of 

 too free a flow of sap."' 



He also objects to summer pruning on the ground 

 that the leaves will interfere with the progress of the 

 workman — but this appears to be a futile objection 

 because they will not be sufficiently developed to do 

 this to any great extent if the operation is performed at 

 the proper time. 



Another objection is that there might be danger of 

 other trees in the neighborhood of those operated upon 

 being injured, but this could only be the result of care- 

 lessness, and damages thus caused would, if the season 

 wore right, be cured — at once. So far from its being 

 immaterial as when trees should be pruned, I opine that 

 it is of the utmost consequence that it should be done 

 at a certain period of growth. 



There is a well established axiom that a continual 

 struggle is going on between growth and decay; one of 

 whicli will eventually gain the mastery. 



Thus when a surgical operation is to he performed 

 the patient is prepared so that he may be in as healthy 

 and vigorous condition as possible — vitality being 

 necessary to a speedy and complete treating of the 

 wound. 



Reasoning by analogy, a tree is in the most perfect 

 state of vitality when its sap is in the process of elabora- 

 ti(ui and assimilation and then it will be in the best 

 condition to produce Uie now tissue required to cover 

 and heal the cut which may have been made. It is a 

 well established fact that sap has a double action moimt- 

 ing from the roots through every ramification of the 

 tree, to the leaves, in a thin liquid, where it is elab- 

 oi-ated, and these having absorbed and decomposed the 

 carbonic acid, the sap descends again in a changed con- 

 dition and is deposited year after year in the successive 

 concentric layers which form the bulk of the tree. 



If that be so the sap cannot be said to descend to the 

 roots, but to have been used up in its progress thereto. 



