Dan Gill — LSU Ag Center
I have always thought of gardening as a “green” activity. Indeed, the horticulture industry that includes wholesale nursery growers, retail nurseries and landscape installation and maintenance companies has long been known as the “green industry.”
Times are changing, however, and the term green industry is now being used to include any business or industry that focuses on sustainability and protecting the environment, such as alternative energy sources, energy conservation and recycled or sustainable building materials and techniques.
When it comes to gardening, it could be argued that some of the things we do, including using gas-powered equipment, over-applying fertilizers or the careless use of pesticides, are not necessarily “green” as we think of the word today. Gardeners can, however, so things to make their gardens and gardening efforts more sustainable and have less of an environmental impact.
Reduce pesticide use
The first thing we can do is raise our tolerance to damage from insects and diseases. If a pest problem is not life-threatening or liable to cause serious damage and if the plants will eventually get over it on their own, then using pesticides is not critical. We also can choose to use plants in our landscapes that are not prone to major insect or disease problems.
Native plants should be used whenever appropriate. Although they get their share of insect and disease problems, natives are adapted to the pest problems here. They most often will tolerate the pest and recover on their own. Using natives in the landscape also provides plants that are fed upon by native animals and helps replace native vegetation that is lost through building and development.
When pest control is needed, seek out and use control methods that do not require the use of pesticides – chemical or organic. This might include biological controls such as beneficial insects or Bacillus thuringiensis, hand picking, barriers and traps. When pesticides are needed, select the least-toxic effective product and apply it carefully just to the affected plants.
Herbicides are, perhaps, the most commonly used pesticides in the landscape. They can be invaluable in helping to control difficult weed problems. Where you can apply mulches, however, which is really just about any place in the landscape except lawns, they are our best way to prevent weeds without using herbicides.
Keeping lawns healthy and vigorous with proper care will help minimize the need for herbicides in the lawn. Personally, I’m not that bothered by a few lawn weeds. But if you feel a situation warrants using an herbicide, choose one that does not include fertilizer and reduce the amount you use by only applying it to the areas of the lawn where the weed is an issue. This is called spot treating.
Reduce the use of gas-powered equipment
Lawnmowers are the most commonly used piece of power equipment for landscape maintenance. The larger our lawn areas, the more we have to use our mowers – using more gas and creating more pollution. We need lawns for playing, outdoor living and aesthetics, but reducing the size of lawn areas by planting shrubs or ground covers or by using mulches reduces both the amount of time spent mowing and pollution. Areas that are mulched or planted with shrubs or ground covers also generally reduce the use of water, fertilizer and pesticides, such as weed killers.
Electric or manual versions of tools such as mowers, string trimmers, chain saws and hedge trimmers are available. Electric versions can be considered for use where power outlets and using extension cords are convenient. Manual tools are more appropriate for smaller rather than larger landscapes.
Reduce the use
Gardeners have somehow gotten it into their heads that the abundant use of fertilizers is important or even critical for healthy plants. Many gardeners probably fertilize far more than is needed.
The regular use of fertilizers is most important for plants growing in containers. Their roots are confined to a small volume of soil and frequent watering leaches out nutrients rapidly. A slow-release fertilizer is the best way to fertilize container plants.
Vegetables and flowers are expected to perform at a very high level, so adequate nutrients are important for good results. But even here, moderate fertilizer applications are generally all that are needed. And organic sources, like compost and manures, can provide these nutrients while recycling yard wastes and livestock industry byproducts.
It is rarely critical to annually fertilize established trees and shrubs.
While shrubs may be removing nutrients from the soil as they grow, both the leaves the shrubs drop and the organic mulch you have in the bed help replenish those nutrients without adding fertilizers.
The overuse of fertilizers, both chemical and organic, but especially highly soluble chemical fertilizers, can contribute significantly to the pollution of lakes, ponds and streams. In addition, plants pushed with an overabundance of nutrients may produce weak growth more prone to pest problems.
Small changes add up and can do a lot to make your landscape and gardens more environmentally green.
Dan Gill is a horticulturist with the LSU AgCenter and is known as a reliable source of helpful, useful advice on lawn and garden topics. He can be reached at DGill@agcenter.lsu.edu