Readers of this blog and our websites will know all about Tom Ogren, the originator of the concept of low allergen gardening, the inventor of the OPALS allergy scale and the author of The Allergy Fighting Garden, Safe Sex in the Garden and a number of other books linking the massive rise in respiratory allergy with the increase in the number of male trees in our urban environments. (See his site for more.)
(To encapsulate 35 years work on one brief paragraph…. In nature there is roughly an even balance of male and female trees. Male trees push out clouds of pollen into the atmosphere; female street suck it in out of the atmosphere. But while male trees only push pollen into the atmosphere, female trees, in urban environments, create seeds and fruits which drop on pavements, creating both mess and a hazard for pedestrians. So town planners over the last 50+ years have tended to plants only males trees. The result is that, in urban environments, we now have significantly more male trees than females – and they are pushing out far more pollen than the available female trees can suck up. Hence much more pollen in the atmosphere to be breathed in – and reacted to – by humans. Combine this with other forms of air borne pollution – of which more in another blog – and you create a perfect storm for those who are prone to react to airborne allergens.)
Anyhow….. Tom was here in London last week and while he was here, I persuaded him to take a trip around my garden – because what you have in your own garden really can make a difference to how you react, even if you live in a heavily ‘male-tree’d’ town. So here he is, pointing out my good, my bad and my ugly allergenic plants…..