WHAT'S the worst plant-pest in your garden? Slugs and snails? Or perhaps rabbits, or even deer? They're incorrigible, aren't they? And upsetting too, inspiring that special mixture of depression and anger when you find that a favourite plant has been callously consumed for somebody's dinner.
But spare a thought for the gardeners at Dublin Zoo imagine how they feel when they arrive in the morning to find that the peacocks have stripped the hostas, the geese have ravaged the newly planted Carex and the Colobus monkeys have been bouncing up and down in the cordylines on their new island. It's enough to make a grown man cry.
After 15 years at the zoo, Stephen Butler, Curator of Horticulture, has learned to accept calmly the damage caused by the animals - including little humans whose dainty fingers are often busy plucking and picking. Instead of wringing his hands in despair, he doggedly experiments, and observes, and researches until he hits upon plants that are animal-proof. Take the Colobus monkeys, for instance: while they love to chew on the tall, feathery Miscanthus grass, they show no interest in Stipa gigantea, the giant oats. So that's a plant that will feature in future monkey-proof plantings.
The geese - who, thank goodness, confine most of their activities to the lakeside - are among the worst culprits, greedily mowing down greenery with their chomping bills. Much of the lake's edge is planted up with Carex pendula, a native sedge with graceful, drooping flower heads. Mature plants are virtually goose-proof, as the tasty young shoots are protected within their centres, but for the first couple years they must be carefully fenced off. Libertia grandiflora, a member of the iris family with starry, white flowers, has proved to be wonderfully goose-resistant, and in the zoo's nursery hundreds of potted seedlings are being grown on. Not surprisingly, euphorbias which exude a nasty sap - and the slinking hellebore are also bird-proof.
But Stephen Butler's work at the zoo is not just fabricating menus of unpalatable vegetation. He is a man with a mission - to educate each of the 350,000 visitors who passes through annually. Where possible, he uses plants that are from the same regions as the animals. So, before you enter the East African Reptile House you are treated to a display of African plants: arum lilies, red hot pokers, gladioli, pelargoniums, tree heathers. All are labelled with their common and botanical names and families and interesting snippets of information. Did you know that the only bamboo native to Africa is Thamnocalamus tessallatus? And that it is used to construct Zulu shields?
In the future, as certain areas are redeveloped or as new areas are created (part of the ongoing major changes at the zoo), there will be more geographically-themed planting. Avocados in various stages of growth, destined for the South American house, fill the nursery. Also here are Irish plants ramsons, cowslips, bluebells, hazel, holly - ready to go into the new pets' corner, based on a country farm.
From time to time unusual weeds spring up in the zoo, such as the rash of cannabis plants - hastily cleared away - in one of the monkey areas. The seeds, which are of the hemp variety rather than the narcotic, are often in animal feeds. And then there are the furry kiwi plants that appear here and there. Strangest of these is the one in the old chimpanzee pen, growing in a wall 15 feet above ground level. However did it get there? "Well," says Stephen, "the chimps have a rather nasty habit of throwing things at you. And," he adds, helpfully, "as the paddock is swept every day they can only throw what they produce themselves."
In the line new monkey area by the lake (the enclosures are well out of missile range), Stephen and his hard-working team of gardeners have planted swathes of banana trees, bamboos, ferns, fatsias and giant echiums. Nourished by the dung from "Dublin's best manure heap" with elephants, llamas, rhinos, hippos, camels and giraffes all doing their bit - they will soon grow up to make a partial screen around the compounds: "In a few years, you will have slightly more trouble seeing the animals because there will be more plants around," says Stephen. "But it makes the animals happier, and you're basically planting for the animals."
Stephen Butler is available to give guided tours of the zoo and lectures to horticultural societies and organised groups. He can be contacted at the zoo, telephone: 01-6771425
Diary date
Tomorrow from 2-5 p.m., there will be a garden party in aid of the Alzheimers Society at Roseville, 36 Dublin Road, Bray. Roseville is the single-handed work of plantsman Dermot Kehoe, and is full of things to delight keen gardeners. Plant sales. Admission Pounds 2. The garden is also open on July 27th, 2-5 p.m.