HALF-HARDY BULBS
Acidantheras--Albucas--Alstroemerias--Androstephiums--Besseras--
Boussingaultias--Bravoas--Cypellas--Dahlias--Galaxias--Geissorhizas
and Hesperanthas
ACIDANTHERAS
The only species of Acidanthera which has been introduced hardy enough
to be classed with half-hardy bulbs is A. bicolor, a pretty plant with
spikes of whitish flowers with the lower segments spotted purple. It
may be grown outside in a warm border if treated like a half-hardy
Gladiolus, or better, under glass as recommended for the Ixia.
ALBUCAS
Only a few of the Albucas, which come near to the Ornithogalums,
deserve cultivation; these can be grown outside in warm districts
alone, on a raised bed of rather light soil, in a sunny position,
protected in winter by a layer of litter. They are, however, better in
the greenhouse or frame. Aurea, yellow; fastigiata, white; and Nelsoni,
white, are the best in cultivation. They bloom in summer, and may be
planted three inches deep in autumn.
ALSTROEMERIAS
Apart from the hardier Alstroemerias, which may also advantageously
be grown in frames or in cold greenhouses, there are several others
which are pleasing occupants of frames and cool greenhouses, from which
severe frosts are excluded. The least hardy of all is A. caryophyllæa,
which should always have a little heat, and does best in a warm
greenhouse or stove. Eminently suitable for the frame or the greenhouse
without heat are the charming pelegrina, white or yellow, striped with
rose, and with a yellow spot on its segments; and its white variety,
alba, a lovely thing. Then there are Errembaultii, a pretty hybrid,
white, spotted purple; pulchra, purple, white, and yellow, with red
spots, and brasiliensis, with its reddish yellow flowers spotted with
brown. At one time these were more grown, and a renewed demand would
bring many other species into cultivation. A light rich soil is
suitable for all, with plenty of water while growing but very little
afterwards.
ANDROSTEPHIUMS
These are pretty bulbous plants resembling the Brodiæas, and hardy if
planted six or seven inches deep, but better grown in a frame. They
like a sunny position and a light soil. The species are breviflorum and
violaceum.
BESSERAS
Few people know the Bessera, which is a pretty little bulbous plant
from Mexico, bearing some resemblance to the Scillas, but having bright
scarlet or scarlet and white flowers. It grows from one and a half to
two feet high, and may be treated similarly to the Babianas. It is one
of the many half-hardy bulbs which might be more widely cultivated with
advantage.
BOUSSINGAULTIAS
B. baselloides is a rather pretty trailing plant which gives clusters
of white flowers in late autumn. In a few districts it is hardy, but it
ought usually to have the protection of a frame in winter, or to have
its tuberous roots stored in sand until spring, when it may be planted
about three inches deep. It likes a rich, but light soil.
BRAVOAS
Bravoa geminiflora, the only one of the three species in cultivation,
is hardy in warm places in the south, but for most gardens its proper
treatment is that of a frame bulb. It has beautiful orange-red,
drooping flowers in July, on stems from one and a half to two feet
high. It likes a light, sandy soil, and may be planted about three
inches deep in autumn.
CYPELLAS
These are pretty plants allied to the Iris, and well suited for growing
in pots in the greenhouse as well as for frame cultivation. They may
also be planted out in spring, and lifted in autumn and potted. They
like a light, sandy soil, and may be planted two inches deep in pots,
or three inches if in a frame. In the latter it is well to give them a
little covering in frosty weather. They may be raised from seeds or
increased by offsets. Cypellas grow from one to three feet high. The
most desirable are Herberti, yellow; peruviana, yellow, spotted
red-brown; and plumbea (syn. Pohlia platensis), lead-coloured, with a
tinge of yellow in the centre.
DAHLIAS
The Dahlia is too extensive a subject to permit of its being fully
considered in the limits of this work, but, without entering upon
particulars regarding the various sections and varieties of the flower,
it may be helpful to give a few broad cultural details for the benefit
of those who grow the flower to a limited extent. It is a plant which
must have generous treatment, and to give this it is essential that the
ground should be deeply prepared by digging, and thoroughly manured
with well-decayed manure. The plants may be put out as soon as danger
from severe frost is past, and they should be allowed plenty of room.
For exhibition purposes from five to six feet apart will be found a
suitable distance. The plants should be staked immediately, and covered
at nights when there is a prospect of a cold night occurring. Pots
filled with moss or hay may be placed on the top of the stakes and
examined regularly for earwigs. When the plants begin to make growth,
the soil ought to be well mulched with half-rotted manure. Watering
should never be neglected, and as the plants grow they must be properly
tied to the stakes. Thinning and disbudding are necessary to secure the
largest possible blooms for exhibition flowers. These may also require
to be shaded and protected from bad weather. When the plants are
destroyed by frost in autumn, they may be cut down to within six inches
of the surface of the soil, and, after leaving them in the ground for a
few days, lifted and stored out of the reach of frost. Dahlias are
propagated by seeds, division of the tubers, and by cuttings, the two
last being the only way of propagating named varieties. Seeds are sown
in pans or pots in March under glass. When the young plants can be
handled, prick them out into small pots and grow under glass until
large enough to plant out in the beds. Old tubers may be divided if a
portion of the crown with an eye or bud is attached to each piece.
These must be put into small pots and grown on for a short time.
Cuttings are easily struck from February to August. In spring the old
tubers are placed in heat with the crowns above the soil, and the
shoots taken off when about three inches long, and struck in heat in
single pots of light soil. Cuttings taken off in summer and rooted in
small pots, form good "pot roots" for planting out in spring.
GALAXIAS
Few people grow these pretty little bulbous plants, which do well in a
frame with some protection in winter, although, perhaps, even better in
pots in a cool greenhouse. They bloom in May, the clusters of flowers
being almost stemless. Graminea has yellow flowers, and the other
species, ovata, has purple-violet blooms. They belong to the Irids. A
sandy peat is the soil they prefer.
GEISSORHIZAS AND HESPERANTHAS
These are closely related to each other, and require practically the
same cultural treatment. The Geissorhiza is a pretty little plant, but
both it and the Hesperantha seem a little more tender than the Ixia and
do best with greenhouse treatment. They may be potted and grown in the
way recommended for Ixias under glass. Both have loose spikes of
flowers. They bloom in May or June.
Practically the only Geissorhiza grown in Britain is G. rochensis,
a charming thing, with Tyrian blue flowers with crimson blotches,
but alba, white; and violacea, light blue, are also procurable;
while a demand for them would probably bring out humilis, yellow;
purpureolutea, purple-black and yellow; secunda, red, rose, and
white, with a number of others from South Africa.
The Hesperanthas are even less grown, but one may meet with graminea
and pumila, white, and pilosa, rose, out of the twenty-six or so
species known. Their drawback is that they flower in the evening.