Garden Pests and Diseases – Do You Always Have to Spray?
With the onset of spring in the Southern hemisphere, and the bursting into life of so many of your garden plants, many unwanted organisms also make an appearance and feed off your favourite flowers, roses and others. The main visitors at this time are aphids and fungi such as powdery mildew. At the first sign of trouble though, do you have to resort to spraying pesticides on the affected plants? Do you want to?
Personally I’ve never met a home gardener who claims to enjoy using poisons Most are disgusted, rightly, even by the thought. The garden is supposed to enhance the quality of life, not be a battle ground for chemical warfare! Also, the more you use pesticides, the more you drive away wildlife from the garden, which help to keep the pests in check. Birds, lizards, many insects such as ladybirds, hedgehogs, and more, prey on the organisms which damage your ornamentals. So the aim should be to make the garden as bio-friendly as possible.
Are we trying to eliminate the pests? Absolutely not! There is one ecological fact worth bearing in mind. In any given habitat, the prey will always vastly outnumber the predator. You’ve all seen the nature films – thousands of zebras and half a dozen lionesses trying to catch one. So no zebras means no lions. And that means of course, no pests, no birds. But what happens then? As insects can often produce something like 20 generations in a year, the next generation of pests has less predators to contend with, resulting in a habitat which is actually more friendly to the pests!
This would be a good opportunity to share with you an interesting statistic I heard from an expert at the Israeli Ministry of Agriculture. He pointed out to me that his department offers emergency field visits to farmers complaining of some mysterious pest or disease eating up their crops. 50% of the “pests” turn out to be non biotic in origin, such as fertilizer or pesticide build-up in the soil.
Indeed once a former customer phoned me in a panic, telling me that his lawn was being eaten-up by “something” and that the neighbours’ gardener had already told them what pesticide to use. When I examined the grass, which was indeed browning-off, I discovered that the automatic irrigation system had been accidentally turned off. This in a country (Israel) where there’s no rain between April and October; a classic case of the problem with the lawn, having absolutely nothing to do with the activity of some pathogenic organism.
The main reasons why the home gardener should try to avoid the use of pesticides as much as possible can be summarized as follows:
* Spraying endangers the person who is spraying
* Pesticides, particularly organic phosphates, endanger members of the family using the garden
* Pesticides reduce the populations of wildlife visiting the garden, thereby affecting the balance in the garden in favour of the pests
In the meantime here are some eco-friendly, indeed family – friendly tips for coping with the uninvited guests:
* Spray the aphids which are dining on the leaves and young juicy stems, with the garden hose. You may have to run your fingers up and down the stems, in order to crush them as well. Will this get rid of all the aphids? No. But it can sufficiently reduce the damage caused. You can use the hose on many fungal infections as well.
After this wait for a hot dry period like the Sirocco in Southern Italy or the Hamsin in the Eastern Mediterranean. These kill off the remaining aphids.
* Prune the tips of affected plants. Aphids concentrate on new growth, and are therefore found at the growing tips of plants. This method of aphid control,is excellent on non – flowering plants, but it will reduce the number of flowers of course on roses for example.
* When pruning, always remove the pruned parts from the garden bed. Never leave them on the ground, because they can become a source for other pests such as boring insects. This applies to all prunings, not just to infested parts, good sanitation is an integral part of pest control.
* Time your watering when the humidity is naturally high, such as at daybreak. As fungi thrive on a mixture of warm and moist conditions, the worst possible time to water is often in the early evening.
* As a last but one resort, use non poisonous pesticides such as those based on detergents or plant extracts. These are less affective than poisons, but less nasty as well.
Prevention is always better than cure, and more and more gardeners are realizing that dealing with pests is a matter of general horticultural practice. Believe it or not, how we irrigate, feed and prune, even how the garden is designed, all affect the level of pests and diseases present in the garden, and the degree of damage caused.
This approach known as IPM – Integrated Pest management, is the one generally accepted today by horticultural and landscaping professionals. The good news is that what’s good for the garden is good for you and your family too!
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