June i, 1907. 
3? 2 THE GARDENING WORLD. 
1879. Making a Rockery. 
I enclose a plan of a part of m3' garden. 
The Rose bed is at one end shaded by, and 
probably injured by, the roots of a large 
Sycamore tree outside the wall. I had 
some idea of cutting off a part of that end 
of the Rose bed and putting a rockery' in 
the corner. As you see, it would face about 
west, but would get all the sun from about 
middaw Would you kindly' give me your 
advice (r) as to the suitability of the posi¬ 
tion for a rocker}', (2) if suitable, as to the 
best way of making it ? I should say that 
the native stone of the district is chalk and 
fdirut. I could get a few fair-sized pieces 
of softer stone, but not many to begin with. 
(Lower Hardres, Kent.) 
We quite agree with you that a Rose bed 
shaded by trees cannot give satisfaction. A 
good plan would be to take out a trench 
just inside the wall, round both sides of 
that angle, and cut the roots of the tree, if 
the latter is sufficiently far away from the 
wall that its stability will not be endan¬ 
gered by the cutting of large roots. In 
some gardens it is necessary to open a trench 
frequently' to stop the invasion of roots. 
We should have no fear of making a rockery 
that would give satisfaction where it faces 
any of the cardinal points. There are 
plants that will grow and flower under 
either of these conditions if not overhung 
by trees. It would be a case of selection 
for a northern aspect. A very large num¬ 
ber of plants would, however, succeed and 
flower well on a western aspect. Indeed, 
when rockeries are made on any' extensive 
scale, a skilled hand would take care to 
provide situations facing all the cardinal 
points to meet the requirements of different 
plants. We presume you wish to make a 
rockery in that corner so that it will face 
the garden and all the plants can be seen 
from the garden side. That being the case, 
you can build up the soil to be highest in 
the corner. It need not be all of one slope. 
For instance, a central ridge might run 
from the middle of the outer margin right 
into the corner, which is the highest point. 
You would then have one portion facing 
south-west and another part north-west. 
The latter would be in full view from the 
grass path next the brick wall. The body 
of the rockery should consist of soil, the 
worst of which may be put in the bottom 
and the best on the top. Do not make the 
mistake of filling up the centre with stones 
and rubbish of that sort, otherwise the 
rockery will always be dry for a great 
depth, and }'ou could not keep it properly 
watered. Hard pieces of chalk would 
answer very well for making a rockery, 
provided it did not get unsightly in winter 
owing to its being crumbled down by frost. 
Flint is a bad stone for rockeries, although 
some would regard it as ornamental. We 
should only use it where strong growing 
plants are to be placed. Hard stones are 
liable to get heated in summer and spoil 
the foliage of valuable plants. It would 
take a deal of time to tell you in words 
how to build a rockery, but on the scale that 
you indicate there is room for making un¬ 
dulations with bays or recesses, and, at 
least, a few projecting points, where a 
boulder or two of stone could remain only 
partly hidden by the plants. On the other 
hand", vou might lay the ground out in ter¬ 
races, but whichever plan of building, you 
adopt, vou should always make provision 
for fairly level spaces or pockets in which 
to grow plants. If any portion of the soil 
is on a steep slope, heavy rain will tend 
to wash awav the soil, and any water that 
y'ou may eive would simply run off it. Give 
an eye, therefore, to the'levels of these 
pockets, so that the water will run into the 
soil and not away by the surface. Tn some 
cases, builders of rockeries use stones to 
build up the front of pockets, and where 
these join, a little cement, placed incon¬ 
spicuously in the angles, serves to join the 
stones and to keep the water from running 
away. On any future occasion, as you 
happen to get fresh quantities of some soft 
or porous stone, you could remove pieces 
that are built with flint, replacing the latter 
with the stone. Limestone, or rather oolitic 
stone that is very suitable would be Bath 
or Portland. Derbyshire tufa would also 
belong to the same category. Provided you 
could get red sandstone from Devon or other 
district in which it may be had, that would 
also prove suitable. The magnesian lime¬ 
stone from the Cheddar Cliffs is also a use¬ 
ful stone for rockeries. You could also 
have artificially made concrete imitating the 
natural strata of various kinds of stones. 
We do not think brick burrs, that is, over 
burned bricks, very suitable for rockeries, 
as they have a very artificial appearance, 
and some of them are so glazed that they' 
get overheated with the sun. If the brick 
walls are fairly strong, the soil laid up in 
the angle would not prove very injurious 
to the walls unless the foundations are 
weak. Lateral pressure would not be very 
great unless the soil is of great depth, and 
we do not see that it need be so in this par¬ 
ticular instance. 
1880. Planting- Out Dahlias. 
For some time past we have had very cold 
winds and showers of sleet. In former 
years I have planted out Dahlias before this 
time, but I am doubtful about the weather 
this year. Do y'ou think they would get 
killed if we had a frost? The plants are 
6 in. high. (A. Broadbent, Cumberland.) 
Some people do plant Dahlias even in 
April or May, but they are mostly people 
who have no heated house to grow the plants 
to some size. After the plants get advanced 
under glass, they would be liable to injury 
in the case of a frosty night, and even if 
they do not get killed outright, they would 
get a check which might throw them back 
for some weeks, especially if the top gets 
killed. The first or second week of Tune 
is early enough to plant out Dahlias which 
have been started under glass, and even 
then, if frosty nights threaten, we should 
wait a little till the weather becomes more 
settled. If your plants are getting pot- 
bound, the best plan would be to give them 
a shift into a larger size to keep them grow¬ 
ing until the weather settles. 
1’8 81. How to Grow Honesty. 
Wall you kindly lot me know the name 
of the flower enclosed, and how to grow it? 
I have heard it called Honesty. (R. S., 
Liverpool.) 
You are right as to the popular name of 
it. The botanical name is Lunaria annua 
(often named L. biennis). Being biennial 
in habit, it flowers only once, and you must 
raise it from seeds every year. If they were 
sown in heat in March, and planted out, 
they would, in all likelihood, flower late 
the same season. An easier method of deal¬ 
ing with it is to sow the seeds in the open 
ground in April and thin them out, or else 
transplant them into their permanent posi¬ 
tion, where they will flower next spring. 
The specimens you sent us were merely the 
seed pods from which the valves and the 
seeds have been removed. 
188 2. Double White Rocket. 
Could you tell me the best way to propa¬ 
gate the double White Rocket? I mean the 
plant with elongated spikes of double white 
flowers like a Stock, and sweetly scented. 
It is now coming into bloom. (Thos. West- 
max. Northumberland.) 
After the flowers fade away the plant will 
send out a number of crowns, each with its 
tuft of leaves. When this has taken place 
you can cut away every crown with a por¬ 
tion of stem or rootstock, and insert each 
in a thumb pot of light sandy soil. These 
may be placed in a cold frame and ju£ 
kept moist with a rosed watering pot. Th 
pieces of stem will be very short, so tha 
the soil in the pots must be in good worl 
able condition. If not sufficiently damp 
you should water it about half-an-houx bs 
fore you commence to insert the cutting; 
as these must be made quite firm, otherwis 
the leaves will drag them out of the soil 
As soon as they' have made some roots, the 
will show it by sending up more Ires 
leaves. You can then pot them into a siz 
larger and keep them growing strongly 
In September they may be planted out wher 
they are to flower, or the pots can be kep 
plunged in ashes in a cold frame and th 
plants put out next March, when the soi 
is in fairly good order. 
1883. Variety of Iberis. 
Would you say if the enclosed is a nev 
variety of Candytuft, as it seems differen 
from any other in my garden, and is late 
in coming into bloom. It seems to me a ver 
fine one. Any information would be gladh 
received. (W. Woodhouse, Yorks.) 
The Candytuft you sent us was a gardei 
raised form known as Iberis correaefolia 
and is the latest of the evergreen Candytuft: 
to come into bloom. It is also one of th- 
best or the best. It is not new, however 
having been well known in gardens thirt- 
years ago at least. 
1884.. Season for Planting Violas. 
I have read somewhere that beddin; 
Violas should be planted early to get th< 
best results. For the last two y'ears I hao 
planted them in full blcom at the end o: 
May', and they looked well for a fortnight 
but after that they went off and bloomer 
only poorly for a long time. I would b< 
glad of your opinion as to the 'best time t< 
plant these Violas. (R. A. Anderson 
Surrey.) 
If you lived in the north of England in 
stead of the south the Violas would giv< 
more satisfaction than they do by planting 
them in May. The reason why they go of 
is that they have been left till they conn 
into bloom, and the transplanting check; 
growth, .so that all the flowers which com< 
first are produced on the old stems. A bet 
ter plan would be to plant out the Violas 
as early in March as convenient, thus while 
the first stems were pushing into growth the 
roots would be throwing up fresh suckers 
that would continue the display of bloom. 
By early planting you get them established 
before the heat of summer sets in. The 
ground is then moist, and the roots car 
ramify' in the soil, but if June should prov< 
to be a hot month the roots are unable t( 
travel far .and the plants soon give ove. 
flowering. For ordinary bedding purpose- 
the 'best plan is to take cuttings of th< 
Violas about the beginning of Septembe 
and root them either in boxes or in a bee 
made up in a cold frame. During autumr 
and winter these not only make roots bu 
begin to throw up young suckers, and an 
just in the right condition to plant out ir 
March. 
ROSES. 
1885. Rose Leaves Tied in Knots. 
Many of my Rose trees have got their 
leaves tied up in knots, so that they canno- 
open properly. On opening some of their 
I found a grub inside. Can you tell me- 
what this is and the remedy for the same: 
(J. D., Kent.) 
The grubs are no doubt those of some o 
the Rose sawflies, of which there are many 
Two of the more common ones whicl 
roll up the leaves are Blenocampe 
pusilla and Lyda inanita. The first 
named rolls the leaves down at thi 
sides, thereby making a hiding place foi 
itself. The other lives in a tube made uf 
