Don't be trigger happy with insecticides. Just because one plant has a problem insect on it, don't use this as an excuse to spray the whole garden as a preventative measure.
Don't spray insecticides on flowering fruits, vegetables or ornamental flowers during the warm daylight hours. Many insecticides also kill bees which are in fact protected by The Bees Act. As responsible gardeners, remember that bees are one of nature's best pollinators and help us in maintaining a vibrant and healthy garden. If you must spray insecticides, please wait until early evening when the bees have finished their daily forays to our gardens.
When confronted by insects in the garden, first decide whether the 'big chemical guns' are required. Remember that most insecticides are toxic to a broad range of insects, including the many beneficial ones, and linger on the plant until washed away by rain or watering.
Healthy gardens need a wide range of beneficial insects to pollinate the flowers and to prey on the insects which do cause problems. Therefore, always approach insect problems with the attitude that you are preserving the beneficial insects but controlling (because you can never irradicate) the problem insects.
The first line of action should always be to use non-toxic control methods first. Practice a daily 'Insect Patrol' of your gardens to check for insect invaders. Some insects, especially if you detect them when they first arrive in the garden, can be hand-picked from the few affected plants. Insect damage can be reduced by physically knocking the insects off the plant, by shaking or using a jet of water from a hose. Once on the ground they become easy prey for benficial insect 'eaters'.
Some of the safer chemical controls use a 'contact' chemical which kills the insect only if it comes in contact with the offending insect. Soapy water sprays are one of the safest insecticides to use for this reason. When they contact an insect, they plug up the breathing pores of the insect and suffocate it. While liquid dishwashing detergents can be used, products which are formulated with more effective detergents are on the market (e.g. Safers Soap). You should rinse the soap solution off the plant after about 10 minutes, because these same soaps can plug up the breathing pores of the plants and cause harm to them. Prepare detergent solutions by mixing 1 ounze detergent to 40 ounzes of water.
Part 2: Lawn Maintenance without Chemicals
Introduction.
Many people are concerned about using chemicals in their flower beds because they recognize that insecticides can also unintentionally kill beneficial insects and birds visiting their gardens.
I hope that this same concern applies to the rest of the property including the lawn. For years I have been involved with citizens' groups concerned about the impacts of locating turf farms and golf courses in wetland habitatas. The chemicals and fertilizers used in these industries are the same ones used by home owners. The following are notes used in a course we used to teach on 'Gardening with Perennials'.
Why Lawns? - A Little History.
Historically, (when forest-dwelling beasts, on all continents, threatened the day-to-day safety of humans) forest clearings and meadows allowed people to ‘see’ their territory and have some advance warning of advancing predators or enemies. Taming nature of its wildness and unpredictability had survival benefits for people. The concepts of lawns (i.e. well-kept meadows) and formal gardens gradually evolved from survival activities to beautification projects around the home environment.
Modern day employment practices leave little spare time for many families to undertake yard maintenance. This has lead to the phenomenal rise in reliance on lawn care companies to maintain the family grounds. The chemical revolution of the 1950's lead to time saving benefits by implementing 'chemical' lawn management practices. Long-term environmental consequences of this trend were 'swept under the carpet' by everyone - the homeowner included.
Today, with greater environmental knowledge, many people are looking for a re-connection to their natural environment and are questioning the need to carry on with outdated historical practices. Many people are looking for a chance to give something back to nature and recognize that they can do this by starting at home with environmentally friendly property maintenance procedures.
The extent of Lawns ( and thus the potential for environmental problems from chemical applications)
- In the U.S., each household maintains about 1/3 acre lawn (averaged).
- In the U.S., lawns cover over 20 million acres (the size of Pennsylvania). This makes 'lawns’ the largest single agricultural ‘crop’ and makes a significant contribution to the American landscape. In Canada, the same analysis applies but I don’t have acreages to report.
Recognizing some Basic Environmental Principles
- There is a growing recognition that human health is tied to what goes on around us and, most importantly, that ‘we are what we eat & drink’.
- Environmental thinking sees all life as part of nature. Manipulation of the earth’s surface should be carried out with the deepest respect for nature lest nature respond with an irrevocable altering of the very conditions upon which humankind is dependent for survival.
- We can not indiscriminately manipulate our lawns (by adding chemicals) without in some measure diminishing our local, regional and global environmental quality.
Our Home Environment: Lawn Care Companies (especially pesticide/fertilizer companies) Promotional Pitches.
- Ideal lawns contain only grass species - they are free of weeds and pests.
- Lawns which are continuously green and have a uniform appearance through regular mowing should be the target.
Consider some of the following when deciding whether to manage your lawns chemically.
Less than 1% of the estimated 500,000 species of plants, animals and microbes in the US are considered pests.
The other 99% carry out an array of essential functions such as decomposing organic waste, degrading pollutants, recycling nutrients, moderating the structure of the soil, preserving genetic diversity, and serving as vital parts of food chains.
In 1990, the U.S. Senate conducted hearings on the use of chemicals used to maintain a luxurious looking lawn. Considering how lawns are used by people of all ages for so many forms of recreation, some of their findings were startling:
If your lawn were a golf course or a turf farm, there are some chemicals that you would not be permitted to use.
Diazinon is one of these. Massive bird kills (especially Canada Geese that savor fresh-grown grass tips) have been linked to the use of Diazinon in public parks, golf courses and on sod farms. Since 1990, Diazinon has been banned, in the U.S., for commercial use on golf courses and on sod farms but home owners can still use them as they see fit. There are no controls on Diazinon use in Canada.
Fungicides, to control some of the common diseases of highly managed lawn grasses, also kill off the beneficial fungi which decompose materials such as lawn clippings and convert nutrients into forms which can be absorbed by the root hairs of all plants.
Many of the chemicals used to maintain a luxurious looking lawn are fat soluble and are not excreted by the organisms which consume them. This leads to a phenomenon called bio- accumulation whereby these chemicals are passed on to the next member of the food chain and eventually become very concentrated in the last member of each food chain. Few chemicals have been adequately monitored to see which have toxic effects on nature’s many food chains.
Chemicals such as the insecticide DDT (used for mosquito control) and the herbicide 2,4 D (a constituent of the defoliant ‘agent orange’ used in the Vietnam war) are notorious for their disastrous effects on the environment and people. DDT was long ago taken off the North American market, but 2,4 D is still a constituent of many lawn care herbicides and it continues to pose risks for producing cancer and birth defects.
Having the greenest lawn on the block is hardly worth the risk of contaminating our own drinking water supplies.
Impacts of Fertilizers and Chemicals used in Highly Managed Lawns
In the highly managed lawn, lush growth is maintained by fertilizers and watering. Rapid grass growth provides the very conditions favoring the growth of grass diseases and pests.
Interestingly, excess nitrogen fertilization actually increases the grass’s susceptibility to disease, reduces its ability to withstand drought and extreme temperatures, and discourages the growth of the soil’s microorganisms that are beneficial to lawn health.
In nature, lush growth is seldom a prolonged event - there is a hardening-off caused by increasingly severe temperatures and drought uring the summer. This has high survival value for the local ecosystem.
In the highly-managed lawn, regular fertilization results in nutrients being washing out of the soil into ground water and sewers (streams & lakes). Nitrogen, in the form of nitrous oxide gas (produced by biological conversions in the soil) is also lost to the atmosphere and is a further contributor to the greenhouse gases causing global warming.
In nature, ecosystems seldom have excesses of anything – they are in a balance. Natural systems retain and recycle their nutrients.
In the highly managed lawn, grass clippings, and therefore nutrients, are constantly removed. Nutrients are only replaced by the bagful of high-cost fertilizers.
In nature, seasonal cycles see that season’s spent growth, plus dead and decaying aged or diseased materials, returned to the ground where decomposer organisms beak down all biological materials to the basic nutrients ready for re-use by new organisms.
In the highly managed lawn, herbicides are applied to kill off designated ‘weeds’. But they also destroy other beneficial organisms, such as soil fungi, which help convert decomposing materials to food for the lawn.
Yard Maintenance for the Environmentally Concerned
1. Get lawns off high fossil-energy dependent materials - i.e. manufactured and trucked fertilizers, pesticides and even pumped water.
2. Cut the grass less often and at higher than recommended heights (3" to 4" rather than 2" to 3"). This helps develop tougher plants with more resistance to droughts and heat. Taller grass shades out some unwanted broadleaf ‘weed’ plants and protects the soil from the drying effect of wind and sun, thereby reducing the rate at which soils become dry.
3. Leave lawn clippings on the lawn to naturally decompose and recycle nutrients to the grass plants. An acre of lawn produces about 10 cubic yards of grass clippings a year. (= 1 large dump truck load). These clippings contain the equivalent of about 100 pounds of nitrogen. If they are sent to a waste disposal site, decomposition of the grass releases nitrogen that can seep into underground water supplies. Also, the anaerobic decomposition in a dump can produce methane gas that contributes to global warming. Exposed to the air on your lawn, this problem does not exist.
4. Create lawns that include clovers. Clovers are highly beneficial plants because they are able to convert nitrogen, found in the atmosphere, to a form used in plant growth. When nitrogen-converting plants like clovers die, they release nitrogen to the soil in a soluble form ready for uptake by the lawn grasses.
5. Minimize lawn watering. Frequent watering often leads to grass plant diseases caused by fungi that thrive in high humidity conditions. Frequent watering does not induce grass roots to grow deeply enough to be ready to withstand heat or drought.
6. Treat lawns with insecticides only when you are sure that it is essential. In a healthy, species-rich lawn, it is seldom required! If insect problems are severe enough to require treatment, use appropriate biological, rather than chemical, treatments. Milky spore disease, a biological disease of many insects, can be used for most insects that are a treat to the health of lawn grasses. . Few insects found in the lawn are a threat to the health of the lawn.
7. Reduce the amount of high maintenance lawn areas on your property and increase the amount of plantings of native grasses, flowers and shrubs to provide wildlife with food, resting and nesting (reproductive) areas.
8. Grow lawns where lawns can grow. In high shade areas, where grass plants seldom do well, plant other ground covers suited to shady sites. Many shade-loving plants prefer an acidic soil (similar to the soils of natural woodlands). Check the acidity of soils (using cheap, simple soil test kits available at most garden centers) in shady areas and make any soil modifications before planting to avoid disappointments from failed plantings.
9. For the smaller lawn, use hand-pushed reel mowers rather than gas or electric powered ones. New varieties on the market take only slightly more effort to push that the noisy, exhaust-producing versions. Gas-powered mowers have no exhaust controls and contribute higher amounts of pollution than those with exhaust controls.
10. Choose environmentally knowledgeable lawn care companies. Choose companies that feature low maintenance programs rather than ones offering a ‘calendar’ approach (we’ll treat your lawn monthly!) or offering one standard high-maintenance ‘formula’. Tell them that you have learned to accept dandelions and clover in the lawn as a sign that the lawn is a more balanced and a healthier lawn ecosystem. Dandelions are food sources for butterflies and moths that are part of the food chain of insect-eating birds.
For additional information:
Redesigning the American Lawn: A Search for Environmental Harmony. 1993. Borman, F. Herbert et al. Yale University Press. New Haven.166 p.
Weed Control in Lawns & Gardens. 1995. Ontario Ministry of Agriculture, Food and Rural Affairs. Toronto.
Internet users can access much pesticide use information at the following site:
http://www.pan-uk.org/pestnews/contents/Pn31.htm
