108 
THE GARDENING WORLD . 
January 31, 1903. 
The Rock Wall as a Home for Alpine 
Plants. 
Experience teaohesi that ithere is, perhaps, no place better 
suited for the majority of choice Alpines than the rock or 
diy wall, when backed by higher ground, as it secures for them 
a firm base, shelter, and a cool, moist root run. By varying 
the aspect from north to south so many favourable situations 
are obtainable, and plants as opposite in their requirements as 
Raanondia and Opuntias can be suited'. The recess in the Kew 
rockery, of which an illustration was given at page 13, is a 
capital example of a shady rock 'wall. 
Those living in stony, hilly districts are familiar with this 
kind of wall ; often it is built by the roadlsidle to uphold the 
bank, and is called “ dry,” from the fact that no mortar is 
used in building it. Such, walls are readily constructed, pro¬ 
vided stone is obtainable. When the first course isi laid, see 
that it has a firm foundation, and that it and each -succeeding 
course tips slightly towards the back, leaving a space there of 
1 ft. or more to bei filled up with a suitable! compost; a small 
quantity should also he placed between each course as tlie- 
work proceeds. 
The face of the stones can be arranged -to- form a smooth 
slope, or each tier can be placed a little farther back, the result 
being a series of narrow ledges. The rain, falling on these-, 
passes into the crevices, and is there -absorbed by the stone-si, -to 
be given out to the benefit of the plants, in hot, dry weather. 
There are many persons who shrink from the expense o-f 
forming a rockery, and yet would gladly grow a choice col¬ 
lection of Alpines. If they have- a terrace bank, let- them alter 
it to- form a rock wall as described above; if there- is -a walk 
at the foot of it. so much the better—these little plants need 
to be seen closely—but leave a good margin at the foot; so 
many thing-s like t-bat sheltered! pl-a-ce. A sunken path can 
be turned to account in this way. A go-od example of the 
latter can b-e seen at Gravetye; fiber© a pergola is placed over 
it, -affording a slight shade -agreeable to -some plants in the -heat 
of summer. 
A background to the wall can be obtained by planting low 
shrubs at the top. Among those suitable are Rosa wichuriana 
and its hybrids, Berberis Tliunbergii, Genista radiata and his- 
panica, Rhododendron ferrugineum, myrtifolium, and hirsutum, 
Dipplo-pappus- chrysophyllus, Menziesii polifolia, and M. p. alba, 
and forms of Erica cinerea. As these attain age they will 
assume more distinct character, forming a delightful setting to 
the little gems below. 
Many of these shrivel up in dry seasons in the- ordinary 
rockery, but remain perfectly fresh in the wall, even when ex¬ 
posed to full sun. The Androsaces, encrusted Saxifragas, and 
Optuntias appear quite at home; water soon passes away from 
them, nor do the worms disturb their roots. Many of the 
Campanulas, especially C. gargamica, travel along the crevices 
with easev The little Alpine Poppies come up readily from 
seed sown in April; so-, too-, does Linaria A-lp-ina. An-oantho- 
limon venu-stum becomes more glaucous, and produces it-s lovely 
little flowers in greater profusion. Achillea umbellate i-s a 
good companion for the- rosy purple Aubriefia-s and Phlox 
setacea, which, if planted near the top, stream down the face 
of the wall in sheets o-f colo-ur. Arenaria balearica at the- foot 
of the cool wall takes possession of it by creeping upward. 
Mentha Requieni and Veronica re-pens do the same for warmer 
places. Erinus alpinus seeds and spreads freely. So-m-e of 
the larger Iberis find a comfortable home near the foot. By 
way of contrast to their small foliage, Verba-scums may b-e 
planted. Megasea cordifolia is also very effective in this way. 
Litliosperrnurn pro-stratum is a capital plant for rock work. 
L. petraeum, sometimes known as L. rosmarinifolium, likes 
a tight crevice, with plenty of rooting space behind ; in this it 
resembles Phyteuma como-sum. 
Many others could- be named, but I hope enough h-a-s been 
said to induce someone to try this phase of gardening. The 
present is a very suitable time for building the wall, and the 
planting can be done early in. March, provided the weather is 
suitable. ,T. 0. 
Cucumis Melo. 
The earliest Melons are generally sown about the middle of 
January. To have their permanent quarters in readiness by 
the time plants are large enough to plant out. such work must 
be in evidence by giving the pits a thorough cleaning, the old 
hot-bed cleared out, and refilled with new, sweet material, 
making it as firm as possible by treading; leave for a time to 
settle. A layer of turf, grass downwards, is next required ; on 
this the bed formed, consisting of strong fibrous loam. Make 
firm by ramming. Should the loam be light, an addition of 
marl is beneficial. 
From this sowing fruit is obtainable in May. To keep up a 
succession, sow about the third week in every month. Seed 
sown in moist soil needs no water until germination takes 
place, after which give the seedlings a situation near the glass, 
where they will have full benefit of light, beat, and moisture. 
An average of 75 deg. atmospheric will be found to suit them 
best, except that in proportion as the sunlight increases they 
will readily bear an increase of from 5 deg. to 10 deg., both to 
the roots and growth. 
Soon after the second set of leaves have developed, transfer 
them into the bed already prepared. On no account plant out 
unless the loam is fairly warm. Strict attention should always 
he given to watering, taking care to keep it- away from the 
collar. Frequent applications of liquid manure-water should 
be given after the fruit commences to swell. Water according 
to the weather. Training and stopping needs close attention, 
taking care not- to disturb the foliage. The female blossoms 
should be carefully set by fertilising daily, preference being 
given to the middle of the day for the operation, when the 
pollen will be dry. As soon as three to four fruits are secured 
on each plant, and these are as large as a pigeon's egg, all the 
blossoms must he cut away, male and female, as they appear ; 
each axillary shoot, with a fruit must be stopped one or two 
eyes beyond the fruit, frequent stopping practised with all 
other portions. 
To check the damage often done by red spider and thrip, 
syringe twice daily in favourable weather. Admit air on suit- 
aide occasions; damp the path and walls constantly, except 
when fruit is setting. Admit more air, and discontinue damp¬ 
ing when fruit is ripening. 
Various methods of supporting the fruit are practised. I 
find that of placing a square board to rest the fruit- on, sus¬ 
pended from the trellis by means of string or copper wire 
secured at-each comer, the best. A. .T. M. 
The Latest Electric Light. 
The latest departure in electric lighting, which is a mercury 
vapour lamp, invented by Mr. Peter Cooper Hewitt, son of ex- 
Mayor Hewiti, of New York, is being shown by the British 
Westingho-use Company. 
This lamp is claimed to be wonderfully successful. It con¬ 
tains no red rays, does not produce violent- contrasts of light 
and shadow, and is said to be extraordinarily soothing to the 
eyes. 
The light is also credited with excellent results in “ forcing ” 
flowers and vegetables in hothouses, and in various branches 
of photography. It- is produced by confining mercury in glass 
tubes from which the air has been exhausted and passing an 
electric current through them. The mercury is vaporised and 
becomes luminously incandescent. 
*** The prize last week in the Readers’ Competition was 
awarded to A. G. Salter for his article on “Begonia 
Gloire de Lorraine,” p. 75. 
