February 8, 1919 



HORTICULTURE 



125 



ENDURANCE OF CONIFEROUS TREES AT 



WELLSELEY, MASS. 



1 have been interested in reading Mr. Horsey "s report 

 on the condition of the coniferous trees and shrubs, after 

 the severe winter of 1917-1918 in Highland Park, 

 Rochester, N. Y., in ELorticultube of Jan. 4th, 1919. 



It may be interesting to make a comparison as to the 

 way the same plants came through on the Hunnewell es- 

 tate, Wellesley, Mass. For easy reference, I will take 

 the plants in the order given in Horticulture, and add 

 notes on any grown hejre, not in the collection at 

 Rochester. 



The terms "hardy" and "hardiness," it seems to me, 

 do not always (or cannot always) apply to a plant's 

 ability to endure a low temperature. Hardiness, I 

 think, in its fullest meaning, should be "endurance," or 

 a plant's ability to stand the climatic conditions of its 

 environment, for its active lifetime. When a plant's 

 activities grow less, as they do when it has reached its 

 usual life-limit, it may be killed during a severe winter. 

 But that would be from old age. In the woods, every 

 winter, we fell trees that are dead, or nearly so, and we 

 always find more dead ones, after a severe winter like 

 the last. Hardiness may even also be considered in 

 reference to a plant's ability to withstand occasional 

 excessively high temperatures. There is no doubt that 

 the reason why the common White Spruce, Picea alba 

 (P. canadensis) does not thrive here, is because our 

 summers are too warm. It is short lived. Massachu- 

 setts may be said to be its southern limit. And may 

 that not be the reason why the common Blue Spruce, 

 Picea Parryana, is short lived. Both do well as young 

 trees, but they do not keep it up. The same may be said 

 of our Red and Black Spruces, plants common in the 

 north and northeast. The common Arborvitae was bad- 

 ly injured in many places last winter, but it could not 

 properly be said that it was not hardy on account of 

 its inability to stand a low temperature. Many plants 

 which are hardy, under natural conditions, are tender 

 under cultivation. 



Some unusual things happen at times, which the term 

 "hardiness" does not quite cover. Our common moun- 

 tain laurel, Kalmia latifolia is frequently injured. This 

 we know is native in this locality, and although we 

 would naturally charge it to the severity of our win- 

 ters, I do not think we properly can. We should rather 

 say, it is not quite hardy, or that it suffers occasionally, 

 under cultivation. No doubt, the injuries to many other 

 plants may be explained in the same way. Those, like 

 the Japanese yew. that endure under all conditions, arc 

 worthy the title of "Ironclad." 



Then again, we have the unexplainable condition of 

 plants, native of more southern latitudes, which are 

 quite as hardy as natives, under cultivation. In tins 

 connection T would mention the southern Hemlock, 

 Tsuga earoliniana, which never, or hardly ever, has 

 been injured here, while the Common Tsuga canadensis 

 is quite frequently sunburnt during winter. 



When going through England and Scotland some 

 years ago, I found that while the Pacific coast ever- 

 greens thrived splendidly, the hardier (with us) Rocky 

 Mountain species did generally quite poorly, as well 

 as most of the Japanese species of firs and spruces. 

 Even our own White Pine, is nowhere a success "over 



there." If you ask them why you are unhesitatingly 

 told, because they are not hardy. This is not the true 

 explanation, — if hardiness and degrees of cold go to- 

 gether, there is some other. , 



Although last winter was probably the most severe 

 for a quarter of a century, our Rhododendrons and Kal- 

 mias came through better than usual; and we are unable 

 to give any reason. 



If any plant that may live for years, but is repeatedly 

 injured, like < 'hama'i -vparis Lawsoniana, and Libo- 

 cedrus decurrens, 1 should say "not hardy." Any plant 

 that lives, but does not thrive, like Abies grandis, A. 

 nnliilis and Tsuga Sieboldii, I could only say "unde- 

 sirable." 



There is still another class of plaids, to which refer- 

 ence should be made in this connection. Many of E. H. 

 Wilson's introductions from China proved tender during 

 the first few years of their seedling life; but afterwards 

 when the flush of youth had gone by, they settled down 

 into a life of hardihood; they might easily have been dis- 

 carded as not hardy, and, in fact, many were. Experi- 

 ence proved that injury came from the grossness of 

 growth under cultivation, made late in the season, and 

 not properly ripened. In this connection I mention 

 Spirea Veitdiii ; we all but discarded it. As the plants 

 grew older they made shorter growth, ripened earlier, 

 and now the plant is quite hardy. Taxus cuspidate 

 \ar. chinensis — the tree form of the species has always 

 been injured, but it is always the young growth made 

 late in the season, and there is every prospect, it will get 

 into the habit of maturing its growth earlier, and prove 

 quite hardy. 



Abies amabilis was not injured; Abies balsamea, 

 Douglas broad-leaved, uninjured; Abies cephalonica, in- 

 jured—has been injured before, but never beyond recov- 

 ery; Abies cephalonica, var. Apollinis, is badly cut up and 

 some small plants were killed; Abies cilicica, uninjured: 

 Abies concolor, uninjured; Abies grandis, dead; Abies 

 Nordmanniana, a tree 75 feet high, severely injured. It 

 has been injured so before, but made good. This tree is 

 about 60 years old, and probably will never quite recover. 

 Abies homolepis umbella. uninjured; Abies pectinata, ex- 

 posed and uninjured; Abies Veitchii, uninjured. 



Species not in the Highland Park list grown here are: 

 Abies holophylla, uninjured; Abies brachyphylla, uninjured 

 — this is supposed to be synonymous with Abies homolepis, 

 though in habit and in some other respects it is different; 

 Abies Mariesii, uninjured— this has been injured in previous 

 winters: Abies lasiocarpa true (A. arizonica), uninjured 

 —this also has been injured in previous winters; Abies 

 bifida, injured, and has been injured nearly every winter, 

 and mav be called undesirable. 



Here follows a list of smaller trees, not sufficiently 

 tested. So far the results are: Abies Numidica, uninjured; 

 A. squamata. injured; the remainder of the list uninjured. 

 A. Fargesii, A. Delavayi, A. recurvata, A. Suchuenensis and 

 A. Faxoniana. 



Cedrus atlantica has been tested here and is not hardy: 

 Cedrus Libani. injured more or less every winter, but re- 

 covers and may eventually prove hardy. 



Chamaecyparis pisifera, uninjured — none of its varieties 

 were injured during last winter, but in previous winters 

 Ch. p. aurea has been; Chamaecyparis pisifera squarrosa 

 uninjured — never has been injured, and Chamaecyparis 

 nootkalensis, uninjured, and never has been; Chamaecyparis 

 thyoides, always injured in cultivation, though native ia 

 nearby swamps; Cryptomeria japonica, always injured and 

 undesirable. 



Juniperus chinensis, uninjured, seldom injured: Juni- 



