Low allergen gardening

Michelle Berriedale-Johnson reviews the options

Garden designer Rob Frier, like many keen gardeners, suffers from asthma and hay fever - which he refuses to allow to dictate his gardening although he does take a few sensible precautions. As soon as the sun comes out, on go the sunglasses and out comes the levoceterizine. The combination of the two keep his allergies pretty much under control - although, as he says, he would not run through a field of grass.

Surprisingly - and frustratingly given the prevalence of inhaled and contact allergies - he is rarely asked to design low allergen gardens. The last was for the RHS Tatton Park show in 2003. However, he agrees that provided one understands the basic principles of pollination, it is not difficult to design a very colourful garden which will not reduce its owners to snivelling wrecks for six months of the year.


Male and female
Logically, male plants are anxious to distribute their pollen as widely as they can by whatever means they can, whereas female plants, far from distributing it, are keen to attract pollen to themselves. So female plants scavenge pollen from the air thereby cleaning the environment for the allergy sufferer.

So, rule number one for pollen-allergy sufferers, is to seek out female rather than male plants. However, you do not have to eschew the male entirely...

The wind
Male plants use two carriers for their pollen - the wind and birds and insects.

Because the wind is a very untargeted way of ensuring that your pollen reaches an appropriate female, male plants using wind have to release enormous quantities of it, saturating the air with pollen. Even though not all of that pollen is allergenic, much of it is and there is so much of it that it is impossible to avoid.

Amongst the main families of plants that use the wind to pollinate are grasses, both ornamental and lawn, and trees, such as birch, ash, hornbeam, maple, hazel, and willow.

Bird and insects
The other way to get your pollen out to suitable females is to use birds and insects to carry it. To achieve that you need first to attract the birds and insects and then to ensure that the pollen sticks to them until they get it to an appropriate female.

To attract their ‘couriers’ plants use either very showy, colourful flowers or strong scents. The former are fine for allergic gardeners, the latter not so good as the strong scents can themselves cause a reaction. However, the need to ensure that the pollen sticks to its courier means that it is heavy and sticky and, unless touched, will cause the allergy sufferer few problems.

Way to go...
• Pollen allergy sufferers should aim for either female plants or those which use showy, but preferably unscented flowers to attract birds and insects.
• This does mean that lawns really should be blacklisted. Even when kept very short and mown by someone else they are likely to cause asthmatics and hay fever sufferers problems.

Fortunately there are many other surfaces that can be used, liberally scattered with tubs and pots to soften the lines and give colour, although mould sufferers should avoid wood and bark - see below.

Scented plants
Plants with heavily scented leaves or flowers can also cause problems for hay fever and asthma sufferers so should be avoided.

Some of the worst offenders are scented roses (unscented are fine), carnations and pinks, clematis, jasmine, honeysuckle, wisteria, privet, elder, tomato and lavender.

Mould and fungi
Some people may get through the spring and summer fine only to get clobbered by the autumnal allergic sledgehammer of mould and fungi. And some unfortunate people will get hit by both...

Mould or fungal spores grow on decaying plant material: compost heaps, piles of dead leaves, rotting wood in wood piles or decking. The spores are extremely light and all but invisible and can travel for thousands of miles. They tend to settle on hedges and lawns and can be released in clouds after heavy rain or thunderstorms. Some mould spores, Aspergillus in particular, are especially bad for asthma sufferers and can lead to severe chronic asthma.

Way to go...
• Keep your garden meticulously clear of autumn leaves and any rotting material - no compost heap, sadly...
• Avoid wooden surfaces, which could rot.
• Avoid hedges and lawns, which could trap fungal spores blown on the wind from other people’s compost heaps.
• Close windows and stay inside after rain or a thunder storm; if you must go out, wear a mask.

Contact/skin allergies
Some plants are, of course, actually poisonous (laburnum, delphiniums, iris etc) but many others have sap or tiny hairs which can cause allergic reactions - eczema, urticaria, contact dermatitis and photo-dermatitis.

In photodermatitis the combination of contact with the plant and sunlight can produce redness, itching and blistering, which can last for weeks and may leave the skin discoloured. The herb rue (Ruta graveolens) is particularly bad for this.

These allergens are easier to deal with than inhaled ones because they are easier to avoid, Ideally, they should be banned from the garden but if you cannot bear to do that, make sure that you always wear gloves which cover the wrist and that you do not touch your face or arms with the gloves that have been in contact with the allergenic plants.

Some of the worst offenders are marigolds, geraniums, castor oil plant, euphorbia, hellebores, daisy, primulas, ivy, daphne, fremontia, privet, fig, rue, dandelion, couch grass.

More information
Disappointingly there is no more information available on low-allergen gardening than there was when we last looked at it three years ago - which is not to say that the two books which are available are not excellent guides.

Creating a low allergen garden by Lucy Huntington was first published in 1998 but remains an excellent and comprehensive guide to low-allergen gardening. Some copies are still available from Amazon.

The American garden designer Tom Ogren has written a couple of low-allergen books. In Safe Sex in the Garden and Other Propositions for an Allergy-Free World, Tom Ogren berates town planners and garden designers alike for planting ‘tidy’ but heavy pollen-shedding-male trees, which do not litter city street with fruits and seeds but do inflict endless misery on asthma and hay fever sufferers.
(You can find all of Tom's books on allergen-free gardening here on Amazon in the UK and here on Amazon in the US.)

Meanwhile, if you would like some help with planning your low allergen garden, who better to ask than Rob Frier. You will find him on 0161 905 3871 or check out www.charlesworthdesign.com.

Plants to avoid:
Fallen leavdes
Ferns (except sterile cultivars)
Flowering cherry
Roses - depending on variety

Plants to use:
Japanese quince

First published in 2007

Articles on allergen-free gardening


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