One of the most beautiful and easy-going perennials for a shaded garden is the hellebore, sometimes known as the winter or Lenten rose, which begins to bloom in July. The original plants were Helleborus orientalis but those seen now are generally complex crosses between that and various other hellebore species, and are known as Helleborus x hybridus and referred to colloquially as Orientalis Hybrids. The large single or double, saucer-like, nodding flowers look as if they have been exquisitely sculpted from wax of subtle and fascinating colours such as pale yellow, near black, purple, slate-grey, green, greenish-pink, greenish-white, pink, clear white or dark plum. They are often delightfully spotted, veined or picotee-edged in a contrasting colour, and are extraordinarily long lasting, remaining attractive until spring. Even as they age gracefully into greenish senescence, they have a delicate charm. Floated in a bowl indoors they make intriguing winter floral arrangements (make sure you put them in water as soon as they are cut so they don't wilt!). It is best to buy a hellebore when it is in flower, as seedlings can vary enormously in colour. Recent hybrids include those with upward-facing blooms; others have frilled 'anemone' centres.
These hellebores will succeed in Sydney gardens if given the right situation. They relish cool, humus-rich, reasonably moist but well-drained conditions and will not establish well in poor or boggy soil. They can tolerate some dryness once established. They appreciate not being crowded by nearby plants: plenty of airflow around the plant will help to reduce the likelihood of fungal diseases on the foliage. They are best in part shade and should be protected from hot summer sun but enjoy winter sun, if such a spot can be found for them in the garden. Once they have settled in, they are long lived and tough plants, forming large ground-covering clumps around 45-60 cm tall and creating self-sown dynasties around them. If they are grown in a raised bed, it is easier to admire the downward-facing blooms!
The handsome, divided leaves are more or less evergreen, but the really tatty old leaves can be removed in February or March. Fresh new foliage will soon appear and the flowers will be displayed better, rather than being obscured by shabby leaves. Removing the old foliage also helps to control fungal infection of the leaves, and will show whether there are aphids present on new growth. Aphids are the main pest of hellebores - and some types can actually kill the plants - and can be despatched with a suitable spray or insecticidal soap. The plants appreciate a layer of organic mulch and some low-nitrogen fertiliser applied in late summer when the flower buds are forming. If there are still some shabby leaves at flowering time, these can also be removed then. After flowering is over, they can be given an all-purpose plant food.
Although hellebores in general are said to like alkaline soil, Helleborus orientalis can often be found in the wild growing on slightly acidic soil and the Orientalis Hybrids seem to be similarly adaptable. Hellebores can be grown permanently in pots and placed in a prominent position once they are in bloom. They will need to be divided or else moved into larger pots as the clumps expand. It is possible to divide or move clumps of hellebores in autumn, though they will sulk for quite a while afterwards. Digging up young seedlings and potting them on another way of propagating them, and this is better than leaving the baby plants in situ, where they can be starved of nutrients by the parent clumps. They transplant quite well, when young. There is no guarantee that the seedlings will look like their parents - but who knows, they may be ever better!
Hellebores can make a good groundcover under deciduous trees as long as there is not severe competition from fibrous roots. The pink or white blooms of shrubs such as Daphne, laurus tinus (Viburnum tinus), Magnolia, Camellia japonica or even Abutilon can be matched with hellebores of similar or harmonising colours and will be in flower at the same time. White hellebores also look very beautiful when grown near silvery-coloured groundcovers and small shrubs which tolerate shaded positions, such as Lamium 'White Nancy' (ht 15 cm), silver plectranthus (Plectranthus argentatus, ht 1m) or aluminium plant (Pilea cadierei, ht 45 cm); or those with white or cream markings on their leaves such as the white-variegated form of Iris japonica (ht 30 cm) or liriope (ht 30-60 cm). The white-belled snowflake bulb (Leucojum aestivum, ht 45 cm) is an excellent companion, as it enjoys the same garden conditions, and has the same nodding characteristic to its blooms.
Pink or purplish flowered hellebores look attractive with ground-covering plants with purple-suffused foliage which can grow in shade, such as Ajuga reptans 'Atropurpurea' (ht 5cm) and Tradescantia pallida 'Purpurea'; or beneath burgundy-leaved shrubs such as Austromyrtus 'Blushing Beauty' (ht 1.5m) and goldfussia (Strobilanthes anisophyllus, ht 1m). The dainty sprays of London pride (Crassula multicava, ht 25 cm) can also provide a pretty background, as the tiny pink and white stars of this tough succulent groundcover contrast with the bolder flowers of the hellebore. The darkest maroon-flowered hellebores could be well matched by a fringe of ebony leaves of black mondo grass (Ophiopogon planiscapus 'Nigrescens', ht 25 cm), and they also look stunning paired with snowflakes.
Green and primrose yellow forms of these hellebores associate well with plain or variegated yellow or lime foliage plants which tolerate shady sites, such as shrubby Euonymus 'Green 'n' Gold' (ht 1m), the fine soft tufts of grassy Acorus gramineus 'Ogon' (ht 25 cm), stripy liriope (ht 30-60 cm) or golden moneywort (Lysimachia nummularia 'Aurea', ht 8 cm). In early spring, they will look pleasing with the blue flowers of Pulmonaria, Ajuga, bluebells and polyanthus.
All these hellebores are regarded as useful bee plants.
It is best to buy these plants from a specialist nursery.