104 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ August 4, 1887. 
thoroughly thawed. The great enemy is damp, therefore ventilate, and 
after the middle of February growth may be accelerated by moderate 
ventilation through the day and closing early in the afternoon, so as to 
husband the sun heat. Water will of course be necessary in the spring, 
giving it in the morning of a prospective fine day. The best varieties are 
Veit h’s Perfect Gem, Early Paris Market, and All the Year Bound. If 
the season be a late one the Lettuces may not be fit to cut until April, hut 
we have often been driven to the expedient of moving the frames and 
protecting the Lettuces with mats, having sticks hoop-fashion to keep the 
mats off the plants, the plants being well hardened previously. We have 
very often been surprised to find that we had finer and heavier Lettuces in 
that way than by continuing the lights over the plants. In that way we 
have had early Cos, and th- best of those is Hick’s.Hardy White and Bath 
or Brown Black-seeded. The frames may also be employed for affording 
protection to Cauliflower plants, which will bear exposure after March, or 
the frames may be used for early Radishes, sowing so soon in the new 
year as the weather is favourable. The best for this purpose are 
Extra Early White Forcing Turnip, Extra Early Scarlet Forcing White 
Turnip, French Breakfast, and Wood’s Frame, the two first bringing us 
the best returns. Radishes require a rich light soil, moderately firm. 
The Pear Tree Slug (H. L., Dunmow ).—The best remedy for this 
troublesome pest is to dust the'trees frequently with quicklime. In refer¬ 
ence to this insect, Curtis—under the head of “ Tenthredo adumbrata ”— 
says, “ Arboriculturists are familiar with a slimy black larva like a little 
leech which appeal’s as if glued to the leaves of Pear trees, and which is of 
Fig. 12.—Tenthredo adumbrata (larva state). 
very co mm on occurrence in fruit gardens in September and October. From 
its form and appearance Reaumur called it the slug-worm. At the end of 
autumn, when it has attained its full size, it somewhat resembles a small 
tadpole. It has twenty feet, which, however, cannot be seen without dis¬ 
lodging it from the leaf. It does not begin at the edges of the Pear leaf, 
but gnaws away the parenchyma in the middle, leaving the smallest veins 
and the epidermis of the under side 
untouched, so that the leaves at¬ 
tacked are left like the finest lace. 
After four times casting its skin it 
changes to an orange-yellow colour, 
comes down from the tree, and 
forms a cocoon from particles of 
soil bound together by a few silken 
threads. The perfect insect, ac¬ 
cording to Hartig, is 2J lines long, 
smooth, black, and shining, with 
the horns almost as long as the 
abdomen ; the legs are black, the 
joints and thighs reddish-brown, 
the wings obscure.” The grub is 
frequently very destructive to wall 
trees. It appears on Pear trees 
when the fruit are from one-half to 
two-thirds of their full size, and by destroying the parenchyma of the 
leaves it prevents the elaboration of the sap, brings grow h to a standstill, 
and the Pears, iostead of swelling, drop. Some authors consider that the 
si g worm of Reaumur produces the Tenthredo Cerasi of Lmnseus ; others 
consider it to belong to the Tenthredo jEthiops of Fabricius. The 
investigations of Gorsky, Westwood, and M. Delacour, have set the 
question at rest. They have shown that there are several slug like grubs 
which are developed into insects belonging to distinct species, and that 
the T. Cerasi of Linnaeus does not form its cocoon in the ground, hut 
amongst the leaves of the Cherry. 
Fig. 13.—Tenthredo p(1 umbra!a 
(perfi ct infeet). 
House for Marechal Niel Rose Cultivation (S. S .).—'This superb 
Rose is grown in a lean-to house at Burghley and other pi ices, and in span- 
roofs at Ascot and others. A description of the Ascot houses and Roses 
was published in the Journal on page 21, January I4th, 1886. For early 
work lean-to houses have an advantage over spans, but that makes little 
difference when the season is advanced. The width of the house is not 
material, as we have seen quite as fine Roses in a house 6 feet wide as in 
one of four times the wid h ; the chief consideration is to allow the growths 
plen’y of space to develope in with full exposure to light, therefore in a 
narrow house it is a question of having less plants, tuey having in any 
case plenty of room. When Mardchal Niel Rose does well it will make a 
growth of 20 feet, and much more in a season, and that extent of run of 
trellis should be allowed. An 18 feet lean-to is a rood width, having front 
or side lights of about 2 feet 6 inches resting on brickwork just clear of the 
ground. The back wall is not much use, and ought not to be less than 
15 feet high from the floor line, which may be very well where a wall 
exists, but where it would have to he built a span-roofed house would be 
much the h st, having it from 20 to 24 feet wide, with side lights of about 
2 feet 6 inches in height, but that is not material for boarded sides do just 
as well, and need not be more than 18 inches high ; a board of 9 iuches 
width fixed just beneath the eaves plate with 4-inch butts' and opening 
outwards from the bottom the whole length of the house will give all the 
needed bottom ventilation. There will also need to be double tire extent 
of top ventilation, and it is Jrest in lantern fashion. The ends of a span 
should be north and south, and to have a proper pitch should be two thirds 
the wid'h, or for a house of 24 feet width with 18-inch sides, 9feet 6 inches 
in the centre from the floor to the under side of the ridge. Hot-water 
pipes will be necessary, and we should have two rows—a flow and return 
4-inch pipe for a 24 fe-1 wide bouse, fixed 4 feet from the sides and clear of 
the soil by 6 inches. The roof may be trellLed, the wires 12 inches from 
the glass, planting the Roses on both skies 3feet apart. The bolder should 
be inside, planting the Roses about 18 inches froni the sides. The roots 
may have the run of outside as well as inside borders. A good sound 
loam inclined to be heavy rather than light, with a sixth of old lime 
rubbish, a sprinkling of crushed bones, and a fifth of leaf soil, well 
incorporated, and laid 2 feet thick on a foot of sound drainage, will with 
surface mulclrngs of decompos d manure grow this Rose grandly. Do not 
force the growth the first season by rich feeding, hut let the plants get 
well hold, and then it will send up shoots 20 or 30 feet long that give 
blooms from every well-ripened bud, and the feeding can then he of a 
higher order, using liquid and richer surface dressings. The finer the 
blooms the better the returns. Most Marechal Niel Roses are ruined by 
hurrying them in the first year with flowering them too profusely in the 
second. Let them get hold before they are allowed to carry full crops. 
Watering and Sprinklinr Plants in Hot Weather (IF. J. Page ).—The 
subject is, as you say, undoubtedly important. One of the best gar¬ 
deners has stated that the great rule fo watering plants in general is to 
“give enough water to reach every root, and give no more watering until 
it is required” The continuous drizzle system ruins thousands of pot 
plants, and is just as injurious, if persevered in, to vegetable and flower 
beds A good soaking when wanted, and Stirling the surface afterwards to 
keep the moisture in, or at least to r nder evaporation of moisture very 
gradu il, wi uld be worth a score of the continuous ever \ day or every evening 
shower baths. Of course we make an exception as respects newly planted 
things, where the mere refreshing of the foliage w 11 often be of more 
importance than delug ng the soil with water. W e have frequently noticed 
plants taken from the same place and plan ed under similar circumstances, 
and in one ca e they would be thn ving, and in the other case they would he 
miserable-looking, the crust of the earth being pretty well as hard as pave¬ 
ment, and produced by the great labour of almost continuous surface 
waterings Let us try briefly to explain the cause. Sow a seed or get a 
plant established in well-stirred soil, and however dry the surface, the more 
power'ul the sun, the greater will be the amount of moisture raised from 
the subsoil beneath the roots of the plants, the roots having the benefit of 
that moisture as it passes them and is discharged iuto the atmosphere, to 
form part of the future showers that will refresh the earth, and which will 
generally come in dry weather. This would form one reason against 
frequent indiscriminate rose sprinklings, as being so far not ca led for; but 
they are not only useless for established plants, hut they are worse than 
useless, because actually injurious, and from two causes. First, by mere 
surface sprinklings surface rootlets are encouraged, which are burned up 
and withered as the surf ice mois ure that encouraged them is dried up; 
and, secondlr, these surface sprinklings confine the evaporation to the 
surface, and thus break the conn cting link of the capillary action which 
would have brought moisture to the roo’s from greater depths. The 
sprinkling does not reach the body of the roots, and it stops the rising even 
of vapour from depths beueath them, so that the roots are deprived of 
moisture h oth from above and beneath, and they fall into much thr same 
state as many a row of ealy earthed Celery does when done after the 
general approved fashion, the stems running, and the earth about the roots 
he ng as dry as if it had been baked in an oven. Thirdly, the watering of 
tender plants turned out of doors must he regulated by tee other consider¬ 
ations, so long as cold form- an element to be guarded against. Here one 
of the first elements of success is having the ground warm, and great 
drenchings, unless with wate considerably heated, and the surface stirred 
and r ndered dry, will ever cool the soil by evaporation. In such cases the 
less water the plants have at the roots, so long as they have enough to keep 
them growng, the better w 11 it be for them, and the faster they will grow. 
We have seen bedding plants flooded at an early period, which we should 
not think of doing had we ever so much water at command. A 'ery little 
at the roots, that had been well warmed by the sun’s rays, would he better 
in such circumstances than a gr at quantity, because the greater the 
quantity the more the ground would be cooled by evaporation. Hence a 
cold rain in the end of May or the beginning of June, in such circumstances, 
is only a little better than a severe frost, and is to be guarded against 
accordingly. Hence, al o, when plants are damp enough at the roots, and 
yet the leaves flag under a powerfu sun, it is often better to moisten the 
foliage by a slight sprinkling, to arrest evaporation, instead of deluging the 
roots or soaking the surface soil. Even if the sun shim-s this sprinkling of 
the foliage will do no harm, and it wonderfully refreshes the foliage, and is 
quit-; a different thing from w tering the surface of the ground. The little 
that may fall on the surface of the ground from such a damping of the foliage 
is qui k y raised about the plants in the shape of a r freshing vapour, a 
very different effect being produced from what takes place when a bed is 
sprinkled over regularly fro a one-eighth to half an inch deep. We know 
that frequently more good is done in this way by a few pailfuls of water 
from a syringe or garden engine, than from mmy given at the roots when 
they cannot appropriate it In such cases of transplanting or repotting, 
sudden changes from dull to bright days demand more in the way of evapo¬ 
ration from the foliage than the roots, though moist enough, can at once 
su 'ply; and the ai’resting or modifying of the evaporation, either by 
sprinkling the foliage, or, better still, where practicable, shidiugfora time, 
gives the plants a better chance in all respects than deluging the roots with 
cold water. 
