Time to look out for trilliums
One of the most remarkable of spring flowers, the wood lily, will soon be making its annual appearance. Less than knee-high, it produces a three-petalled flower at the centre point where three, broad, heart-shaped leaves meet. All parts of the plant are in threes, and this structure is the reason for the botanical name, trillium.
It has a series of common names including wood lily, wake robin, birthroot, toad-shade and trinity flower, the last being a reference to the three-part nature of the plant. The wood lily is native to North America with a couple of species from eastern Asia.
The most popular wood lily is the large white-flowered kind with broad petals that roll back a little, giving the plant a lively spring appearance. The white petals are pure-white and eye-catching from a distance, held over fresh green leaves. Other kinds of wake robin have wine-purple upright flowers, rather than reflexed. Very often, the leaves of the purple-flowered kinds are mottled with purple.
In its natural habitat in North America, trillium grows in remarkable sheets of flowers in woodland and scrubby areas where the soil is humusy with a thick surface layer of leaf mould. Leaf mould is better than any other source of organic material for trilliums because it perfectly suits this woodland species.
At planting, plenty of this material should be dug in to an area much bigger than just the planting hole and it should be topped up each year with more leaf mould, unless a natural layer of fallen leaves rots down over it in winter. This plant likes the good drainage that is created by leaf-mould while moisture is retained in the summer months.
Trillium likes some overhead cover but not too dense. The ideal is to have tall trees with clear stems that provide some shade and shelter but allow in a good deal of light and some sunshine, a light dappled shade. Shelter from strong winds is important as the leaves are quite flimsy, broad and easily damaged.
The plants come into leaf in spring and flower in late March, April and May, when trees are opening their leaves but the canopy has not become dense and dark. Most kinds are happy enough in full light, perhaps with some afternoon shade.
The leaves wither away later on, back to a thick rhizome with a bud for spring. The plant clumps up slowly, if conditions are right, and this makes it slow to propagate. Watch out for snail damage to the new shoots in spring. Although delicate in appearance, trillium is hardy and can be grown in cold inland areas of the country.
When should I move my hellebores?
Q. I want to move a large clump of helleborus, the Lenten rose, which is currently in bloom. I am getting conflicting information on when best to do this. Could you advise please?" D Foley, Maynooth, Co Kildare
A. Hellebores can be lifted and divided as soon as the flowers begin to go over and take on a green flush. Hellebore is in active growth now and there will be some wilting, but the plants are robust and recover well. Give them a good watering to settle them in, and water in a dry spell. Or, if you wish, wait until October and move it then.
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