June 21, 188S. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
515 
tion must be proportionately more liberal, and every attention 
given. This practice, however, refers more to summer manage¬ 
ment than to winter : the months of April, May, and June are 
more concerned than, perhaps, any others. In all cases the chief 
point is to know the character of climate and amount of tempera¬ 
ture the plants or trees require, and that, too, with regard to their 
condition and the period. This kind of knowledge is not speedily 
acquired certainly, and I lament that I cannot impart it in a few 
words. The following may be taken as maxims generally correct: 
—A very copious admission of front air, and little at back or the 
apex, has a tendency to create a great disparity between the tem¬ 
perature at back and front, and to chill the frontage. Much back 
air and little front is likely to encourage a keen draught. When 
cutting winds or a very sharp air therefore prevail, it is frequently 
good policy to give no front air unless compelled. But thexc are 
no maxims which bear continual sway : as conditions change we 
must change our policy also. 
In early forcing, such as Vines, &c., perhaps more caution is 
needed than in most things, particularly during the months of 
January and February, for then the sun has little power ; but when 
the forcing gets into ISIarch he finds the case much altered, and 
this is generally his most trying time. With a bright sunshine 
and a cutting south-easter he is sometimes at his wits’ end to keep 
things right. By-the-by, of all the winds that blow perhaps a 
south-eastern is the worst for glazed structures, especially lean-to 
houses. They are every moment robbing the roof of its warmth, 
and the roof borrowing from the interior. As for giving air, 
especially front air, extreme caution is frequently requisite, and 
when absolutely necessary in such circumstances, it would be well 
if we could have some finely pierced apparatus to riddle it into the 
house. We all know how the very early Cucumber forcer—in 
■dung beds—occasionally takes the precaution of nailing a mat or 
canvas over the air-giving points in order to break the fierce 
action of the air, and, as it were, to riddle it through. As for the 
ordinary greenhouse, that is the easiest to ventilate of most struc¬ 
tures, and I need not say much on that head. 
Ventilation is frequently had recourse to as a preventive of 
drip, and very necessary too. I have a Camellia house svhich is 
notorious for drip, the house having been glazed some years since. 
I have Camellias in constant blossom from the early part of 
November until May, and we rarely have one blemished by drip. 
This is owing to the constant ‘maintenance of air day and night, 
both at a high or a low level ; and the constant use of very 
moderate firing, by which the hot-water pipes are always lukewarm. 
This induces a lively circulation of air, which dissipates the vapours 
before they can become condensed. One excellent adjunct in the 
prevention of drip would be a roof covering to prevent con¬ 
densation, but such are very perishable and difficult to work during 
the alternations of frost and thaw. The prevention of drip, 
as to blossoming plants in winter and early spring, is a most 
important affair ; and in conjunction with the pains taken over 
ventilation and firing much discretion should be exercised in the 
application of water, doing so sparingly and principally in the 
morning early. 
There can be no doubt that long-confined and, by consequence, 
stagnant air is highly prejudicial to vegetation in general, especially 
to those plants with thin foliage and of speedy growth. There is 
overy reason to believe in an analogy between animals and plants 
in this respect. Foul or stagnant air long continued casts a skin 
over the foliage of plants, and this, by partially closing their 
'‘breathing pores,” of course vitiates their juices, or impedes 
reciprocity between the foliage and the root, which is of great 
importance. And how can we expect plants or trees to blossom in 
full vigour, with all their parts perfect, without that subtile, yet 
invigorating element—pure air ? As to insects, fungi, &c., if you 
want any for special purposes, you will only waste your time by 
hunting hothouses where judicious ventilation is maintained, and 
where, by a cleanly system, all corruption or irritation is met half 
way. The drawing of plants or trees, alias weakening, alias 
elongation of the joints, with some other aliases, is, of course, 
clearly traceable to a want of free circulation, as also to too much 
closely confined damp-producing attenuation, and a scant of the 
colouring deposit in the leaves of plants, called- chlorophyll. Let 
me here, too, wai’n the uninformed of that affair called excitability 
or a disposition to receive damage on any extreme of atmospheric 
conditions. The longer garden structures are kept badly ventilated 
the more this kind of tenderness increases. The colours of 
flowers, too, and the flavour of fruits are very incomplete without 
free ventilation. 
Before concluding my explanations I must beg to offer an 
opinion that if all hothouses were properly constructed and pro¬ 
perly heated, together with that full amount of provision for air 
moisture, which would, when necessary, prove equal to any demand, 
there is scarcely anything we cultivate but would be better for air¬ 
giving night and day. This I have certainly never seen realised, 
and never had it in my power to carry out; but it is an old convic¬ 
tion, and I am by no means solitary in the opinion. Indeed, when 
it is considered that everything we cultivate in houses not only 
endures but enjoys such conditions in their wild state, how is it 
possible to doubt it ? The great obstacle, it would appear, to a full 
recognition of this fact is the dread of over-dry indoor atmosphere, 
through the constant loss of vapour; but surely we have means 
in these times of producing as constant a supply. One thing may 
here be observed; that in severe weather, or when there is a certain 
amount of discrepancy between the inside and outside air, and air 
moisture continues to be engendered within, it is very apt to 
descend in drip, a thing by all means to be avoided. Now with a 
constant ventilation there is no need to fear this drip. Of course, 
such would consume a little more fuel, but this amount would not 
bo found very material. 
It is only proper, however, to remark here that, although con¬ 
stant ventilation might be congenial to the inmates of our houses 
in general, yet there are many special objects in gardening which 
demand other considerations. The early forcer, endeavouring to 
produce his Grapes, Pines, Peaches, &c., for sale or for exhibition, 
has frequently to push them forward by all possible means, and 
such circumstances require that a great amount of sun heat be 
enclosed betimes in the afternoon, and a high and moist atmosphere 
preserved during the earlier part of the night. I have here to 
confess that constant ventilation would frequently cause the loss 
of a week or two, and this is, in many cases, a serious affair as 
concerns market prices or exliibition days. Early Cucumbers 
seem particularly to enjoy this close shutting up; it of course 
hun'ies them forward. At the same time we all know that Cucum¬ 
bers succeed in the very highest degree in warm summers, and 
under proper circumstances, albeit they are subject to winds, storms, 
and other vicissitudes.—N. E. R. 
GLENSTAL CASTLE GARDENS AND THE 
EHODODEXDEONS. 
One of the most remarkable floral sights of Ireland is afforded by 
the outdoor Rhododendrons at Glenstal Castle, the residence of Sir Croker 
Barrington, Bart., imposingly situated on the southern slope of the 
Slieve Felim Hills. The Castle is comparatively modern, being princi¬ 
pally built in the last generation by the late Sir Mathew, of a hand¬ 
some variety of darkly marbled caen stone found on the estate, and to 
which quarry, some three miles distant, a railroad was run. Though 
seemingly a freestone, time has iwritten no wrinkles on its bold 
towers, turrets, or parapets. The top of the Sir Matthew tower is 
reached by a winding spiral stairway, and from its summit colonnade 
on a bright sunny day, such as we were fortunate in having, a lovely 
landscape greeted the eye in every direction. Limerick was due west, 
some dozen miles ; the Shannon sweeps around through many scenic 
splendours to Castleconnell, less than half the distance, with its fishing, 
archaic, and historic attractions ; while stretching away to the east and 
south, dotted here and there with cosy residences and gardens hidden in 
groves and dells, is the great plain of Limerick, terminating in one 
direction with the Golden Vale and great summit of Gattymore ; while 
the rugged outlines of the Kilvermine Mountain close out the north and 
east. The sparkling sheen of the lake below, with its swans and wild 
fowl, and the competition for a favourite piece of ground between two 
batallions of fallow and red deer, attract the wandering delighted eye 
to the park spread out and undulating below. From this vantage 
point a varied bird’s eye view is obtained of many things of the forest— 
stately Oaks, venerable Elms, and spreading Chestnuts ; while closely 
competing with those in height were many Araucaria imbricata. Ex¬ 
cept at Woodstock, the present fine residence of Lady Louisa Tighe, I 
have seen no finer specimens of Chili Pines than here. They are 
healthy, and seem about 70 feet high. The eye catches in the imme¬ 
diate park landscape many curious, and by no means common, specimens 
of various coloured Lilacs, Philadelphus, and double Deutzias ; Gymno- 
cladus canadense ; and, sheltered by a wall. Magnolia acuminata, that 
the winter seemed to affect badly. Just underneath the terrace garden 
are miniature Heights of Alma' constructed in memory of that cele¬ 
brated battle siege where so many Irish and Britons bravely lost their 
lives. The top rampart was planted with Hypericum calycinum, the 
second with Fuchsia Riccartoni, and underneath Halesia tetraptera. 
Though well protected from north and east, the winter of 1879 and 1880 
was too much for them, and they were killed, leaving the “ Heights of 
Alma” as bare as probably the Russian had their great prototype 
more than a quarter of a century since. AVith just a peep here and there 
at the many remarkable Coniferse, I propose to no longer pretend not to 
see the Rhododendrons. They meet the gaze at the entrance to the 
park ; they stud the margin and islands of the lake ; they front copses 
and skirt glades, peep out from gloomy ravines, and seem equally at 
home 1000 feet above yonder hill escarpment. But we shall ramble 
among them immediately. To see the Coniferm and Rhododendrons to 
advantage we must quit, reluctantly it must be, our perch with the 
coloured sentinel on guanl in the Castle turret, and leave him to _ gaze 
admiringly on the Russian captured cannons below, and on as smiling a 
