People that suffer from allergies know only too well how the misery of watery or red eyes, a runny nose and sneezing can make them feel. More often than not, environmental elements from dust, moulds and spores can be the culprits.
Dioecious plants are those with separate sexes; yes, male and females of the same variety.
Examples of trees that are dioecious are red and silver maples, holly, willow, aspen, poplar, mulberry, cedar, juniper, ash, yews and even asparagus from the vegetable patch has both sexes. In the case of hollies, a male is needed nearby for pollination of the flowers on the female and nurseries generally will have a piece of each in the same pot. If you have a holly that’s never flowered and produced the crimson red berries, it could be that there isn’t a male in the area for pollination to take place.
Female trees produce fruits and seeds while the males commonly sold as ‘fruitless’ or ‘seedless’ varieties produce large amounts of allergenic pollen. The berries from a female tree such as the mulberry can be messy on the ground, staining sidewalks and cars and other places as birds carry them off to consume. This could be the lesser of two evils though since they don’t produce pollen and in fact actually trap and remove it from the air.
Pollen particles are so fine that they can pass through a window screen. For the safety of children and elderly people, it is advisable to keep trees and shrubs that produce pollen away from windows. Trees or plants that are desired by the homeowner and do produce pollen can be planted as far away from the house as possible and down wind.
Pets can be allergic to pollens too and if they exhibit symptoms in the spring, this is one thing to consider when determining their ailment.
Besides choosing the sex of a tree for the garden, consider planting disease and resistant varieties. An unhealthy tree that develops mildew, rust, or black spot that is reproduced by spores is bound to add to the allergens in the air. Just look at the Norway maples planted along boulevards that inevitably get black spot every year and one has to wonder how they are affecting our environment.
Plants plagued by aphids will have their residue called ‘honeydew’ on the stems and stalks that is a breeding
ground for moulds and mould spores. Washing them off with a blast of water also gets rid of the honeydew and a spray bottle of water tucked behind plants in the garden is readily accessible when they’re spotted.With the introduction of bylaws in Ontario against the use of insecticides, fungicides and herbicides we now have less exposure to chemicals that were causing allergies from inhalation or contact. Organic methods might seem tedious but in the long run are a much healthier alternative.
The last thing to mention is that remember what you plant can also affect your neighbours, especially if they have young children.