Allergy Fighitng Garden

The Allergy Fighting Garden


by Tom Ogren

Stop Asthma and allergies with smart landscaping

Buy "The Allergy-Fighting Garden" from Amazon UK for £14.91

$22.99 from Random House in the US




Estimates vary but allergic rhinitis
(hay fever) is now thought to affect over 20% of both the UK and the US populations with the number of sufferers growing every year. The Royal College of Physicians report on allergy over ten years ago estimated that, in the UK, the prevalence of allergic rhinitis had trebled in the last three decades, and there is nothing to suggest that this rate of increase has slowed.

The population health implications, not to mention the economic cost, of this virtual epidemic are massive; misery, on-going poor health and lost opportunities for millions; billions of pounds or dollars in health care and working days lost. And in mortality terms, research in Holland in 2000 suggested that deaths from heart disease, lung disease and pneumonia, climb by between 5% and 17% on days with peak pollen counts.

Tom Ogren's new book, The Allergy Fighting Garden, tackles the problem head on, blaming the epidemic rise in the incidence of hay fever primarily on town planners:

In the early years of horticulture, most landscape plants were propagated by seed, and therefore male and female plants in the landscape were roughly 50-50, as naturally occurs in the wild. With the advent of powerful new rooting hormones, bottom heat, automatic mist and fogging systems, and controlled atmosphere greenhouses, clonal (asexual) woody plant propagation became much easier, quicker, and cheaper, and it allowed growers to produce separate-sexed (male or female) plants of their choosing.

In the 1940s the United States Department of Agriculture (USDA) started to recommend that when growing separate-sexed (dioecious) trees or shrubs from cuttings, budding, or grafting, that only male scion wood should be used. This, they said, would result in litter-free plants, as male plants make no seeds, seedpods, or fruit to fall on public sidewalks and create a "mess." What was missed was that these same male trees and shrubs would, of course, all produce allergenic pollen—a great deal of pollen. The pollen production of a single large male tree may easily be well more than ten thousand times greater than that of a perfect-flowered tree (one with both male and female parts in the same flowers, such as an apple or a plum tree). As time progressed, clonal trees and shrubs became the rule, not the exception, and more and more male plants were propagated, patented, sold, and planted in our cities.

AcerThe major shift came in the 1960s and 1970s when Dutch elm disease (DED) struck and killed off millions of American elm trees...... DED struck first in the east, and then spread westward over the next decade. The trees that replaced the elms were more often than not these new, "improved" cultivars, male trees, many of which were developed by the USDA. They were first planted in massive numbers in eastern cities, and the eastern cities were the first ones to experience the sudden surge in urban allergies. Eventually, these replacement male trees were planted coast to coast, and as the ones in the west matured (and started to shed pollen), the west started to catch up with the east in the high percentages of people suffering from allergies.

The urban landscape before DED struck was, of course, a highly manipulated environment itself, but almost 100 percent of the street trees were seedlings, not asexually propagated clones. Manipulation of the environment is something that is done all the time in horticulture, and the old elm tree–lined streets were hardly good examples of environmental soundness. They totally lacked in biodiversity, which set the stage for their destruction by DED, but at least they had sexual balance.

Unfortunately, since the 1950s, it has also become common practice in many areas to cut down seedling-grown trees once it's determined that they're female—because they are deemed "messy." Seedling male trees are generally spared, left to grow old and large. This "unnatural selection" has taken a large toll on the females and has left us with ever more urban pollen, because female plants not only produce no pollen themselves, but they also trap and remove pollen from the air. .......

So, between specifically planting large numbers of male clones and the systematic removal of female trees, we have created quite a situation. As is so often the case, when we manipulate large ecosystems and don't consider the consequences.....

This is not the first time that Tom Ogren has addressed this problem – indeed he has been a crusader for low allergen gardening for the last thirty years and, finally, his views are beginning to gain traction. Pollen control ordinances that prohibit the sale or planting of the most allergenic trees are being considered, or have already been implemented in cities such as Albuquerque, Las Vegas; Edmonton and Toronto in Canada, and Christchurch and Auckland in New Zealand.

But although much of his new book is addressed to town planners and city landscapers, Tom maintains that individual hay fever sufferers, even if they live in an area rife with male trees, can do a lot to improve their own lot.

You may wonder whether what you plant in your own yard can make any difference, because pollen can blow in from hundreds of miles away. But what you plant in your own yard most likely will make all the difference in the world. With pollen allergies, everything is in the actual dose received. If you have a headache and take two aspirin it will be just fine, but if you take twenty or thirty aspirin it will be terrible. It is the same thing with exposure to allergenic pollen; a small amount of pollen might well actually even be good for you, it would probably stimulate your immune system. But a very large overdose of pollen will quickly make many people ill. The closer you are to the source of the pollen, the greater your exposure will be.

A large pollinating tree will shed most of its pollen right next to the tree itself. The largest amount of this pollen will be found within a few dozen feet (or less) of the drip line of the tree. If the tree makes allergenic pollen, then those who live closest to this tree will get the biggest dose, the overdose. Yes, some of this pollen may drift on down the block, but exposure next to the tree may easily be well more than a hundred times greater than it would be a few houses away. Allergy researchers call this phenomena "proximity pollinosis."

It is well understood by many allergists that if someone is allergic to, say, six things, and three of them are removed, then the sufferer will often become symptom-free. This is an important insight. By creating an allergy-free yard, you will have eliminated the closest, most intense sources of what ails you. Even though your body will contact some allergens from outside your own area of control, your symptoms will probably diminish and sometimes they'll disappear.......

.....As with so many things, allergy is usually a question of degree. So, with some safer trees in the garden, you might well have remained symptom-free.

Planning and creating a safer garden, either for you or for your city has been made hugely much easier by Tom's development, over the 30 years that he has been studying the subject, of OPALS (the Ogren Plant Allergy Scale). OPALS is a comprehensive catalogue of over 3,000 plants – from alpine creepers to hundred-foot trees – rated on a scale of 1 to 10 for their allergenicity. Whatever you wish to plant, the OPALS scale will provide you with a rating which will allow you to plan a garden or a landscape that will minimise your allergen load.

OgrenIt will also allow you to choose between a multiplicity of colourful and interesting plants – a far cry from the perception that low allergen plants are boring plants! You may not be able to grow too wide a range of grasses but there are many hundreds of other plants which will allow you create exciting, interesting and colourful spaces.

It is the OPALS ratings that make up the majority of the Allergen Fighting Garden – a true plant allergen encyclopedia, complete with many illustrations and much advice, both on using the plants and using other devices (such as high hedges) to protect yourself from your neighbour's or your city's allergens.

The book is a 'must buy' for any hay fever sufferer with gardening aspirations or for any gardener who suffers from hay fever – and it should be required reading for all landscape gardeners, architects who wish to dabble in landscape – and, most especially, town planners!

The Allergy-Fighting Garden
Stop Asthma and Allergies with Smart Landscaping
by Thomas Leo Ogren
ISBN 978-1-60774-491-7

Buy "The Allergy-Fighting Garden" from Amazon UKfor £14.91

$22.99 from Amazon in the US

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