Houstonia Coerulea.--These hardy little evergreens are more generally
known as Bluets. They make charming ornaments for rock-work, planted
between large stones, but in this position they need protection from
severe frosts. When planted in pots and placed in a cold frame they
show to most advantage. A mixture of leaf-mould and sand, and a
moist but well-drained situation is what they delight in. They bloom
continuously from April to July. Height, 3 in.
Hovea Celsi.--A greenhouse shrub, which is evergreen and elegant when
in flower in June. A sandy loam and peat soil is most suitable, and
it may be increased by cuttings planted in sand under a hand-glass.
Height, 3 ft.
Humea.--A remarkably handsome and graceful plant, the leaves of which
when slightly bruised yield a strong odour. It is equally suitable for
the centre of beds or large borders, and placed in pots on terraces or
the lawn it is very effective. The seed should be raised on a gentle
hotbed, then potted off and kept in the greenhouse till the second
year, when it may be turned out into a warm situation. It generally
succeeds better in such a position than in the greenhouse. Flowers in
July. Height, 6 ft. to 8 ft.
Humulus Japonicus.--(_Japanese Hop_).--A hardy annual Hop of rapid
growth, the leaves of which are splashed with white. Useful for
covering arbours, verandahs, etc. A deep, loamy soil suits it best.
Increased by seed sown in gentle heat in February, and gradually
hardened off. Flowers in July. Height, 20 ft.
Hutchinsia Alpina.--This small alpine creeper is a profuse bloomer,
its glistening white flowers being produced at all seasons. It grows
in moist vegetable mould, and bears transplanting at any season. Care,
however, is required to prevent its roots over-running and choking
other things. Height, 2 in.
Hyacinths.--May be grown in pots, in glasses, or in beds and borders.
The soil should be rich and light. Good loam mixed with old manure and
a little leaf-mould and sand suits them very well. If intended to be
grown in pots the best time to begin potting is early in September,
putting more in at intervals of two or three weeks until the end of
December. One bulb is sufficient for a 5-in. or 6-in. pot, or three
may be placed in an 8-in. pot. The soil under the bulb should not be
pressed down. The top of the bulb should be just above the surface.
Place the pots on a bed of ashes in a cold frame, put a small inverted
pot over the top of the bulb, and cover the whole with cocoa-nut fibre
or cinder-ashes to the depth of about 4 in. In about a month roots
will have formed with about 1 in. of top growth. The plants may then
be taken out, gradually exposed to the light, and finally removed to
the conservatory or sunny window. The doubles do best in pots.
For growing in glasses select the firmest and best-shaped bulbs.
Those with single blossoms are preferable, as they are of stronger
constitution than the doubles. Fill the glasses with pure pond or rain
water, so that the bulbs just escape touching it, and put a piece
of charcoal in each glass, and change the water when it becomes
offensive, taking care that the temperature is not below that which is
poured away. Stand the glasses in a cool, dark place for three or four
weeks until the roots have made considerable progress, then gradually
inure to the full light. September is a good time to start the growth.
When planted in beds or borders, place the bulbs about 4 in. deep and
6 in. apart, putting a little silver sand below each one. This may be
done at any time from October till frost sets in. They succeed fairly
well in any good garden soil, but give greatest satisfaction when the
ground is rich and light.
Hyacinthus (_Muscari_).--A very hardy race of spring-flowering bulbs.
Though the varieties are very dissimilar in appearance, they all
produce a good effect, especially when planted in good large clumps.
Plant from September to December. A sandy soil suits them best.
The following are well-known varieties:--_BOTRYOIDES_ (_Grape
Hyacinth_).--Very pretty and hardy, bearing fine spikes of deep,
rich blue flowers in compact clusters on a stem 6 to 9 in. high.
Sweet-scented, and blooms about May. The _Alba_, or white, variety is
also sweet-scented.
Hyacinthus--_continued_.
_CANDICANS_ (_Galtonia_).--The white Cape Hyacinth, or Spire Lily.
A hardy, summer-flowering, bulbous plant 3 ft. to 4 ft. in height,
gracefully surmounted with from twenty to fifty pendent, bell-shaped
snow-white flowers. Thrives in any position and equally suitable for
indoor or outdoor decoration.
_MOSCHATUS_ (_Musk Hyacinth_).--Bears very fragrant purplish flowers.
_PLVMOSUM_ (_Feather Hyacinth_).--A fine, hardy, dwarf plant suitable
for any soil. Its massive sprays of fine blue flowers, arranged in
curious clusters, 5 to 6 in. in length, resemble much-branched slender
coral.
_RACEMOSUM_ (_Starch Hyacinth_).--Rich dark-blue or reddish-purple
flowers. Very free-flowering and fine for massing. It is similar to
the Cape Hyacinth, but flowers in denser spikes.
Hydrangea.--This shrub delights in a moist, sheltered position and
rich soil. It may be increased at any time from cuttings of the young
side-shoots, 2 or 3 in. long, under glass, in sandy soil. The old
stems will also strike if planted in a sheltered situation. The plants
should be cut back when they have done flowering, and protected from
frost; or they may be cut down to the root and covered with manure.
They are well suited for the front of shrubberies, and also make fine
plants for pot cultivation. The flowers are produced in June and July.
Height, 3 ft.
Hymenanthera Crassifolia.--Ornamental evergreen shrubs, thriving best
in a compost of loam and peat. They are increased by cuttings planted
in sand and subjected to a little heat. Height, 6 ft.
Hymenoxys.--Pretty little hardy annuals that may be easily raised
from seed sown early in March in any garden soil. They bloom in June.
Height, 1 ft.
Hypericum (_St. John's Wort_).--Favourite dwarf shrubs. Any soil suits
the hardy kinds, but they prefer shade and moisture. These may be
increased by seed or division. The greenhouse varieties thrive best in
a mixture of loam and peat. Young cuttings placed in sand under glass
will strike. July is their flowering season. Height, 1-1/2 ft. to 2
ft.
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