340 
THE NATIONAL NURSERYMAN 
tli('r(' ;ir(‘ Iwo ^tMH'ral classf's of vaiialions. termed flw:- 
1u(ili(})is and niutdfions. Fliietualioiis are those varia¬ 
tions ^(MH'rally dm* to (MivironnuMd and are not inhei'ited. 
We all kno^\ that variation in liahit of growth, pi'odue- 
tiv(*ness, siz(‘ and prodiietiveness of flowv'r and fruit, is 
largely dm' to ri(*hn('ss of soil and elimatie infliienees. 
Sonu' vari('li('s {*hang(' theii' eharaeter to sueh a great ex¬ 
tent in diff('r('nl loealilies as to l)eeome v('ry dissimilar, as 
lor instanee. tiu' eommon lied (a'dar (Juniperus I4’r- 
(/in’uiua) \\hi(*h in the rieh. moist soils of the Eastern 
Stat('s, is tall and eolunmar. while in the dry. sterile, lime¬ 
stone soils of SOUK' of the Southein states, it forms d 
l)road and si)reading, ii’n'gular tree. Changes that are 
inhei’ilahle an' t('rmed fniitalions. These being instaiieed 
in many of llu' w('ll known garden forms or sports of 
varieties, and ordinarily reproduee true to type from seed, 
and nearly always retain their peeuliar eharaeteristies 
when ])ropagaled from by means of eidtage, J)udding or 
grafting. As is well known l)y gardeners, these muta¬ 
tions generally appear suddenly and without w arning and 
from eauses unknown. They eannot ahvays he pro- 
dueed by hybridization, and one must simply wait and 
propagate from them w lien they are reeognized. 
A'ow those of us w ho have been somewhat observant, 
have noted individual plants in nursery tields or else¬ 
where growing in elose proximity to others of the same 
variety, and a[)})arently under the same eonditions, that 
show very distinet difference in hardiness or ability to 
stand ('xtremes of heat, cold, dryness or excessive mois¬ 
ture. Sometimes, of course, this may be due to different 
grow ing eondilions that eannot be distinguished, but in 
many instances it is the ri'sult of a mutation first show ing 
itself in the individual under notice, or the result of pro- 
})agalion from a mutated parent. Therefore, if such a 
plant, showing unusual hardiness, is pi-ojiagated from, 
there is no doubt that its offspring will inherit its hard¬ 
iness, especially if the propagation is by means of cuttage, 
Imilding or grafting. 
Where the method of propagation is by seedage this 
eannot be so sure, as the blossoms of the jiarent may have 
become cross-fertilized with the pollen from a plant of 
different eharaeteristies, resulting in a different form or 
hybrid. Another method of increasing hardiness, as we 
are all probably well aw are, is the grafting or budding of 
a more or less tender variety on the root or .stock of a 
hardier sort, as in the ease of grafting Lilacs on Lifjus- 
trum ovdlifoliKm, Tea, Hybrid-Tea and Remontant Roses 
on Manetti and Rugosa Stock, Ligustrum Nepalense, Lig- 
Nslrum. excelsum superbum, Ligustrum marginatum 
aureum and macrophgllum on the more hardy L. ovali- 
folium. R has been noticed that Ligustrum coriareum 
tuviduni, is moi*e hardy than L. Nepalense or L. Jajiomcum 
in most localities. Now L. coriareum appears to be a 
hybrid between L. coriareum Nepalense and L. Japon- 
idun, and if this Ite conceded we have here an instanee 
of the hybridization of two distinet varieties producing 
offspring of greater hardiness and distinctive eharaeter. 
There is great room for imj)roved varieties of increased 
hardiness, or types of greater hardiness, ('si)eeially in the 
South. For we have a number of varieties adaj)ted to 
the South that aie hardy much farther north, where the 
more ('ontinuous or even seasons affect their grow ing and 
donuaul periods in a uniform manner, while in the South 
oeeasioiial warm seasons in wintei- induce the rise of 
saj) and produce a soft condition in the plaid, and being 
followed by freezing temperalures result in severe win- 
t('r killing or injury. Therefore, it would seem that by 
the selection of tyjies of varieties that harden off early 
and have a tendency to remain dormani until they are safe 
from being injuri'h by lafi' frosts, the offs[)ring would bi; 
more adapted to w ithstand our jieeuliar w inter seasons to 
betlei' advantage. 
Last wilder in the South was a very disastrous one, 
esjieeially in some loealilies where warm rainy seasons 
oceuiTcd during the winter. In the Rirmingham dis¬ 
trict nearly all of the huge specimens of oriental arbor 
vitaes sueh as Biota aurea prramidalis, Biota aurea con- 
spicuSy and Biota aurea nana were badly injured or killed 
outright, w hieh is the first time this has oeeurred to my 
knowledge. Many othei' varieties of evergreen shrubs 
were badly injured or killed, as the usually hardy Abelia 
grandiflora, Evongmus Japonicus, Ligustrum Japonicum. 
Ligustrum Nepalense, Ligustrum marginatum and L. ex- 
cetsum superbum, and nearly all tea and hybrid tea 
roses, growdng on their own roots, and some growing 
budded on stronger stocks. During this jieriod I made 
frequeid inspection of these varieties on jii’ivate grounds 
w here tw o or more plants of the same variety w ere growl¬ 
ing closely together and in nursery blocks, and was 
strongly impressed with the fact that without a])pareid 
reason one plant would be killed and along side another 
plant hardly if any, injured. Therefore, I would 
strongly recommend that nurserymen should closely ob¬ 
serve ])lants to determine their comj)arative hardiness and 
select the best for propagating purposes. Again I w ould 
urge that nurserymen study the science of hybridization 
with the object of producing new types of varieties of 
greater value in form, size, color of flower, productive¬ 
ness and hardiness and I am sure very gratifying results 
w ill be obtained. 
Notes fronu the Arnold Arboretum 
Rhododendrons. Persons w ho desire to cultivate these 
])lants must remember that Rhododendrons, including all 
Azaleas, cannot live in soil impregnated w ith lime. Rho¬ 
dodendrons are not hardy north of Massachusetts, and 
south of Pennsylvania the summer sun is too hot for them. 
The range therefore in eastern North America w here these 
plants can be successfully cultivated is comj)aralively 
small, but probably the northw est coast of North America 
from southern Rritish Columbia to northern California is 
as w ell suited for these plants as any ])art of the world, 
and there can be grown in addition to all the varieties 
common in Euroj)ean gardens the Himalayan and Chinese 
species which here in the east can only be kej)t alive in 
glass houses, and in Euro})e thrive only in a few excej)- 
tionally favorable ])laces like Cornwall or in the Jieigh- 
borhood of the Italian lakes. 
Rhododendrons, although they are moisture-loving 
plants, do not thrive in undrained j)ositions; they do best 
in soil in which loam and ])eat have been equally mixed, 
although ])eat is not always essential to the successful 
cultivation of these plants. They should be {)lanted wdiere 
the roots of trees cannot take away moisture from them, 
