Doing your bit to save the planet can be as easy as growing a tree, writes Jane Powers
Remember last month's lovely Irish Times supplement on trees? If any of you were inspired with thoughts of planting a tree or two but never quite got round to it, let me gently jog your memory. Now is the time to plant, while trees are still dormant (or, rather, barely snoozing, after this mainly mild winter). Plant for posterity if you have room, so your descendants may have a fat trunk to hug 100 years hence, or plant for more immediate pleasures - perhaps a smaller tree, whose flowers and fruit may delight the bees and birds (and you). Whatever you plant, you're doing your bit for the planet - a point the Tree Council of Ireland, organiser of National Tree Week, which starts tomorrow, is eager to stress.
This year's theme is Harvesting an Ocean of Air, which refers to trees' ability to take carbon dioxide from the atmosphere to make cellulose, after which they breathe oxygen back into the air. Trees process the world's global-warming CO2 exhalations - from burning fossil fuels, driving, flying and manufacturing (even digging holes in the ground releases carbon dioxide) - for us. What wonderful things to have around. A mature beech, for instance, produces enough oxygen in a year to support a family of four.
Yet Ireland is one of the EU's least-wooded countries: average tree cover in the union is 33 per cent; ours is only 9. Crann is dedicated to persuading us to plant more trees and to cherish the ones we already have. Its new booklet, The ABC of Planting Trees, by Crann's chairman, Steven Meyen, is aimed more at tree planters in rural areas than at cramped townies such as myself. Nonetheless, it has abundant good advice that applies to all tree-planters, no matter how big or small their domains.
For instance, be sure to choose the right tree for the right place, paying attention to the soil, microclimate and eventual size of the tree. A point that cannot be reiterated enough is the correct way to stake a tree. Trees should be staked at no more than a third of their height. The stake should not stop the stem moving in the breeze; its purpose is to stabilise the roots and help them grow into the soil. So think of ankle braces rather than walking sticks when attaching a stake to a tree (and never let the tie strangle the tree after a season or two of growth).
The distance from a house (and that includes your neighbour's), says Meyen, should be no less than the eventual height of the tree. Poplars, he warns, should be allowed nowhere near buildings, as their strong roots can block drains and undermine foundations. Suzanne Wallis of the National Garden Exhibition Centre, in Co Wicklow, reminds me that large willows may be similarly destructive. And something I didn't know is that in farming areas weeping willow (a popular tree for large gardens) is prone to septoria, a disease that also attacks wheat.
Cherries remain a favourite garden tree, especially in urban areas. One of the prettiest is the autumn-flowering cherry (Prunus subhirtella 'Autumnalis'), in flower from November until April. But in recent years it has become a martyr to various pests and diseases. Some garden centres no longer stock it. My own specimen, planted 14 years ago, invariably sheds most of its leaves by late summer, weakened by shot hole (a bacterial or fungal disease) and apple leaf miner, tiny green caterpillars that dangle from near invisible threads, like minuscule Christmas decorations, before reeling themselves up into the leaves to devour them from the inside out.
Many cherries have similar problems to the autumn-flowering kind, and few are long-lived. After 50 or 60 years most begin to go to pot. Wallis suggests that varieties of P. serrulata (such as 'Kanzan', with pink double flowers in late spring) may be hardier than their P. subhirtella brethren. Crab apples (Malus) are not terribly long-lived either, while some are prone to apple scab. The recently introduced 'Gorgeous' is a good grower, however, as are 'Evereste' and 'Golden Hornet'.
A tree that is dear to my heart, and easily grown from seed, is the foxglove tree (Paulownia tomentosa). I recommended it the tree supplement, and I hope you don't mind if I do so again. Left to itself (and given some shelter from the wind), it grows into a fine, conical tree (10-15 metres high), with big, lazy leaves and intensely fragrant mauve foxglove blossoms. Or, if you can bear to interfere with it, cut it down each spring to a metre or two from the ground and it will produce leaves large enough to cover two pages of this magazine.
TREE WEEK: SELECTED EVENTS
Tomorrow, 3pm, Devil's Glen Wood, Ashford, Co Wicklow. Guided walk of sculpture trails and wood. Family-friendly day with refreshments. Meet 2.45pm at main car park. Inquiries: 01-2011132.
Wednesday, 2pm, at John F. Kennedy Arboretum, New Ross, Co Wexford. Walk led by Chris Kelly. Admission to arboretum free from March 7th to March 11th. Inquiries: 051-388171.
Thursday, 8pm, at the Minerva Suite, RDS, Ballsbridge, Dublin. Annual Augustine Henry Forestry Lecture, A Visit to China in the Footsteps of Augustine Henry, by Dr Matthew Jebb, taxonomist at the National Botanic Gardens.