To farmers, corn in a soybean field is a weed; to gardeners, last year's tomatoes sprouting in the green bean patch can be called weeds. Generally, but not always, weeds are hard to eliminate. So, what can you do about these pesky plants that grow where you don't want them? There are several ways to control them. First, consider prevention. Removing undesirable plants before they flower and develop seeds will reduce the number of weed seeds added to your garden. Most weeds produce a huge number of seeds. When adding mulch or compost to your garden, be sure that it is weed free. Old weedy hay may be a cheap source of mulch, but it could add unwanted weed seeds that you would have to deal with in future years. While hot composting may kill many seeds, cold composting may not. Remember too, that many seeds lie dormant in the soil for years, so prevention will not guarantee a weed free yard. Secondly, consider control methods. Mulching is effective in preventing weeds from growing in gardens. Mulch smothers weeds by depriving them of sunlight. Organic mulches such as grass clippings or compost are effective in improving the garden soil by increasing the amount of organic matter. Wood chips can deplete soil nitrogen unless fertilizer is added. To be effective, mulches should be applied several inches thick--additional mulch may be needed later in the growing season. If weeds still poke through the mulch or grow in your lawn, try elimination. Depending on the type and number of weeds, various approaches can be used. Many weeds can be removed effectively and safely by physical control methods such as hoeing or pulling. This usually works for a few dandelions or in vegetable gardens when weeds are small. Usually, they are easy to pull when mulch is used. The last method is chemical control. For some hard to destroy or creeping types of weeds, this can be the only way to get rid of them. When using chemicals, follow directions carefully. If the chemical is misused, drifts in the wind, or washes into storm sewers, it could cause death or injury to desirable plants as well as to pets, wildlife, or people. If all else fails, live with them! The weed free perfect lawn is a relatively recent phenomenon. Sometimes the effort needed to maintain a "showcase" weed free lawn is more trouble than it's worth. With the widespread use of bluegrass and the application of broadleaf weed killers routinely applied to many yards, no wonder it is increasingly difficult to find that proverbial four-leaf cover!