ROCK AND WALL GARDENS
THE very worst advice we ever saw given about gardening was given in a
popular magazine in an article on Rock Gardens. It said that all you
wanted for a rockery in a town or suburban garden was a cartload of
stones or _bricks_ dumped down in a corner. We really wondered when we
read it whether the writer thought that plants could feed on bricks.
Soon after reading this nightmare of an article we came across Mrs.
Swanwick’s clever book, ‘The Small Town Garden,’ and we will tell you
what she says about the proper way to start a rockery. ‘If people who
make a rockery would consider that it is to be made of earth, supported
with stones or rocks, they would be much nearer the right method than
those who think of a rockery as a pile of stones with a little soil
dribbled in among them. If we bear these requirements in mind, it
becomes clear that the stones or rocks must be set so as to leave no
hollows empty of soil between them, nor niches kept dry by overhanging
rocks, and the slope of the earth must be such that the rain will not
wash it away, and expose the roots of the plants.’
It may be that a flat, sunny border cannot be spared for you, but that
if you choose you may annex a grass-grown bank or slope of a hill going
up to a stone wall or to shrubs. We will tell you how we once saw a
place of this kind made into a charming rock garden with some blocks
of limestone and a few days’ labour. The bank in this case led from an
upper lawn to a lower one, and had a south aspect. The turf was all
removed, the soil was thoroughly broken and mixed with sand, and then
slabs of limestone were mixed into it, each one with a slight upward
tilt, so as to hold the earth and catch the rain. The great point to
remember about rock gardening is that every stone or rock should be
wedged into the soil a little slantwise, so that the hidden end slants
down and the end you see slants up. You soon find out an elementary
truth of this kind for yourself if you try to grow things in a
badly-made wall or rockery. We once watched someone struggle with a
loosely built granite wall that tilted a little towards him, and which
had no soil in its crevices. He tried stuffing in earth, but as the
slant was wrong it fell out as it dried. No rain reached the roots of
his plants because the top stones sheltered the lower ones, so nothing
that needed moisture would live. Perhaps in the course of years he
might have coaxed some of the house-leeks to find a lodging there; but
as he wanted a wall garden clothed in spring with hanging sheets of
flowering plants, the only way was to pull the wall down and build it
properly. Then it had earth packed into every crevice, and the stones
so arranged that the rain could reach every plant set amongst them.
Some plants, it is true, will live on next to nothing, but there are
very few that will do without rain and will survive when their roots
have reached a hollow place amongst stones.
We think that while you are a child you will probably not have much
chance either of making rock gardens or of building walls; but you may
have a bit of wall or garden that easily lends itself to rock plants,
and would not do well for anything else. In some parts of England
you may have a garden that is rock with a sprinkling of soil on it,
and the difficulty will be to find or make places for vegetables and
deep-rooted shrubs and flowers. In a garden of this kind the children
are quite likely to have a patch where the rocks are showing through
the soil, and where it is difficult to find pockets of earth deep
enough even for Daffodils or Tulips. But there are many beautiful
shallow-rooted plants you can grow in such places as these, for they
will not be like the silly heap of loose stones or bricks described in
the magazine article. For instance, if you put a bit of the Arenaria
Balearica in such a rocky corner as this, it will find its way here and
there, clothing every stone with a mossy carpet, and in spring putting
out thousands of tiny white starry flowers. Then there is a charming
Dwarf Veronica (_Veronica repens_), that seems content with very little
soil, increases at a great rate, and has that pretty way of clothing
the stones and taking their shapes. Another of our favourite common
Alpines is the Campanula Cæspitosa, a small Campanula that sends up
its quivering white or blue bells the whole summer through. It is so
hardy and rambling, and increases so fast, that the fastidious rock
gardener warns you not to let anything precious grow near it.
You will have to find out for yourself which rock plants are so greedy
and pushing that you get tired of their company; for this must depend
on your soil and climate. In Cornwall the little Arenaria Balearica
spreads so quickly that you soon tear it up by the yard, while in the
North of England it seems to increase slowly. In a cold district you
may be glad of things that would overrun you in a warm one. Near a town
people grow whatever will best endure the soot and close air. When you
are older you will have to find out which plants want lime and which
granite, which peat and which sand; but we will only tell you of plants
now that will grow in any ordinary good garden soil mixed with a little
leaf-mould and some small stones, and we will only give you the names
of plants that can be got at any good nursery garden. If you can do so,
get your plants in little pots, and put them into your rockery or your
wall on a showery spring day. But take care that every plant has a
good deep pocket of fresh soil to feed it.
PLANTS FOR A ROCK GARDEN.
_Alyssum Saxatile._—This grows into a dwarf shrub in time, and is
a mass of small, brilliant, yellow flowers in spring. It is very
sweet, and the bees love it. It looks well near Aubrietias, or near
Lithospermum Prostratum. Suitable either for a rock garden or for a
loose stone wall in which you can have a deep pocket of earth for its
roots.
_Antirrhinums_ (_Snapdragons_).—We think the good dwarf ones are
charming on rockeries. We once had some pink ones grown from Sutton’s
seed that were as pretty as little Rose-bushes. On walls some of the
taller ones often look well, and when they are self-sown they seem to
flourish in chinks where there cannot be much food for them. If you
have a wall you should sow a little seed, and be careful not to mistake
the seedlings for weeds.
_Anthericum Liliastrum_ (_St. Bruno’s Lily_).—A charming plant, growing
from one to two feet high, and flowering in May or June. It likes a
sandy loam. If you want to increase it, you can divide it in the autumn.
_Arabis._—If you are a London child, you will have seen this with
London Pride in every London rock garden. It is the commonest of rock
plants, and its white flowers make a pleasant show near Aubrietias and
Alyssum in spring.
_Arenaria Balearica._—This is the little creeping mossy plant we have
told you of already. Put a bit on some soil near any stones you want
covered.
_Aubrietias._—You must know these if you have ever looked at a garden
in spring. They are in various shades of mauve and purple, and make
great sheets of colour on walls and rockeries. It is sometimes called
Purple Rock-Cress. You can divide them in autumn, or you can grow them
from seed sown in May or June.
_Campanulas._—There are many varieties of blue and white Harebells that
do well on walls and rockeries. Pumila, Pulla, and Cæspitosa are three
well-known dwarf ones. Isophylla is a good hanging one, but not quite
hardy. Persicifolia is an easily-grown tall one. They are increased by
division.
_Helianthemums, or Sun Roses._—These must not be confused with the
Cistus, or Rock Roses, which are charming, but not so hardy as the
Helianthemums. If you grow them from seed sown in May or June, you
should in the following year have a number of dwarf shrubs bearing
single flowers in a variety of shades, ranging from white and yellow to
bright crimson.
_Iberis Sempervirens_ is often called Perennial Candytuft. We have
known people buy it by its Latin name, and be much disappointed to find
it was the well-known white flower they had seen in all their friends’
gardens. It is not proud, and will grow almost anywhere.
_Iris Pumila and Iris Stylosa._—We mention two out of the many
beautiful Irises suitable for a rockery. Try to get the variety of
Pumila called Cœrulea, a lovely sky-blue. Stylosa is the scented Iris
that flowers in winter. It likes sun and shelter, and dry, hard ground.
It must be manured.
_Lithospermum Prostratum._—If we were only allowed one rock plant out
of all there are, we would choose this one. It flowers nearly all the
year round in some parts of England, and its blue is as vivid as the
blue of a Gentian. If you can plant it so that its roots can tuck
themselves under a big rock as they grow, so much the better. We have
transplanted a big plant of it successfully, but we did it in fear and
trembling, as it is said to hate disturbance. You had better not try to
divide it. It can only be increased by cuttings, and they are not at
all easy to strike.
_Phlox Setacea._—This is one of several varieties of dwarf Phloxes
that are useful for edgings and rockeries. They must have sun and
well-drained soil, or they damp off.
_Speedwell: Veronica Repens._—There are many varieties and sizes of
Veronica. Some make big garden shrubs. The one we recommend here is
a tiny trailing plant, with small pale blue flowers. It increases at
a great rate, and is easily divided. Slugs like it, but do not make
headway against it in many gardens. It makes a pretty dwarf edging
amongst stones, as it creeps amongst them, and partly covers them.
[Illustration: “THE ROAD TO ROME.”]
_The Sedums, Saxifrages, and House-leeks, or Sempervivums_, are all
suitable for rockeries. Some kinds of Sedums, or Stonecrops, grow wild
in our hedges. You should get Sedum Spectabile, the Japanese Stonecrop,
which bears large heads of pink flowers in August. There are many
widely differing varieties of Saxifrage, or Rockfoil; for instance,
Muscoides, the Mossy Saxifrage, makes a plump, low cushion of green
moss on your rockery; Sarmentosa is the well-known weed, Mother of
Thousands; Umbrosa is London Pride. Some have large leaves and pink
flowers; some send up pyramids of white flowers from tufts of silvery
leaves. You must grow one or two at a time, and get to know them by
degrees. Sempervivums are those little green rosettes you see spreading
in clumps on old roofs and walls. One of the most fascinating is
Sempervivum Arachnoideum, the Cobweb House-leek. It covers itself with
a curious white down that looks like a spider’s web. They like a dry
sandy part of the rock garden, and full exposure to the sun.
Besides these plants, you should put a few bulbs in your rockery. Some
of the very small Daffodils, Narcissus Minimus or Bulbocodium look
charming coming up through a mossy carpet of Arenaria Balearica, for
instance. You could also have some Snowdrops, some Siberian Squills,
some autumn Crocuses, some Fritillaries, and some Dog’s Tooth Violets
(Erythronium Dens Canis). We much prefer the English names for flowers,
but it is often necessary to give both, so that you should recognize
it in the catalogues. We heard of someone who sent to the other end
of England for a plant advertised as Tussilago Fragrans, or the
Winter Heliotrope, and she was much disappointed to receive a bit of
the common Coltsfoot, that was an obnoxious weed in her own garden.
Someone else sent for Hieracium Aurantiacum, which certainly sounds a
first-class name; but she did not want a bit of the orange Hawkweed,
as it had established itself more firmly than she wished in her rock
garden already, and had to be kept in bounds with a spade.
We have not given you separate lists for a sunny and a shady rock
garden, because we shall tell you a little in another chapter about
plants that like shade. You must have some Primroses, Polyanthuses,
and Auriculas on your rockery, and though they like the sun in spring,
the more delicate kinds need some shelter from the hot summer sun. Try
to get Primula rosea, the hardy rose-coloured Himalayan Primrose, and
Primula Cashmeriana, a Primrose that sends up heads of mauve flowers on
a fat stalk. Both need much moisture. Then, the Japanese Primroses are
very handsome, and seed themselves when once established; and Sieboldi,
with its many varieties, is easily increased, either by seed sown in
spring or by division of the roots.
Now we have chosen just a few flowers for your rock garden, and
with every word we write others come and look at us reproachfully,
saying, ‘Why are we left out?’ We see neat little tufts of Thrift, or
Sea-pink, and hanging sheets of white-flowered Cerastium, Anemones of
sorts, Alpine Violas, Forget-me-nots, Hepaticas, Gentians, the finer
Columbines, and shrubs of various kinds and sizes. But we have only
had one aim in writing this chapter, and that was to lead you just one
step towards the rock garden you must make for yourself when you are
older. Then you must get yourself ‘Wall and Water Gardens,’ by Gertrude
Jekyll, and ‘My Rock Garden,’ by Reginald Farrar, two books that will
teach you all that books can about this most fascinating side of garden
craft. But from the first one we should like to quote a short passage
that tells you how a wise gardener supplements what he learns from
books by his own qualities of patience and observation.
‘Nothing is a better lesson in the knowledge of plants,’ says Miss
Jekyll, ‘than to sit down in front of them, and handle them, and look
them over just as carefully as possible; and in no way can such study
be more pleasantly or conveniently carried on than by taking a light
seat to the rock wall and giving plenty of time to each kind of little
plant, examining it closely, and asking oneself and it, Why this? and
Why that? especially if the first glance show two tufts, one with a
better appearance than the other; not to stir from the place until one
has found out why and how it is done, and all about it. Of course a
friend who has already gone through it all can help on the lesson more
quickly, but I doubt whether it is not best to do it all for oneself.’
That is excellent gardening advice, and you can apply it to whatever
you are trying to do, whether it is a rock wall or a patch of Mustard
and Cress.
We must end this chapter with a short list of things we hope you will
never allow in your rock garden, and as they are all to be seen here
and there, you need not say that the advice is unnecessary. Coloured
glass balls, for instance! We assure you that, especially in Germany,
there are many people who think coloured glass balls beautiful objects
in a garden. Others like bits of quartz, and in cottage gardens you
may see sea-shells and broken glass. Then, persons who ought to know
better will make a grimy erection with clinkers or broken bricks, and
a home for Slugs and Woodlice with a rotting tree-stump. You must do
none of these things. If you live where you can easily get stone, have
a rock garden in some form, even if it is only an edging of stones to
your herbaceous border, and grow some of the plants we have told you of
amongst them. If you live where your walls are of brick, you may still
get some plants established on them. For instance, where weeds have
established themselves, you can remove them, stuff in a little good
soil, and sow a few seeds of Snapdragon or Wallflower. Old brick walls
make beautiful wall-gardens, and when the builder is not looking you
can help on the process in a new one with a chisel, a little fine moist
soil, and a few roots or seeds.