Springtime means gardening and lawn chores—mowing, mulching, planting, weeding.

For many weekend gardeners, this is also the time when chemicals make their annual debut—as fertilizers, pesticides, or herbicides. In pursuit of a greener lawn or a pest-free garden, homeowners often become chemists of sorts.

Recent studies, however, have raised a red flag on chemical use, pointing out a possible link between herbicides and pesticides and non-Hodgkin lymphoma, prostate cancer, soft tissue sarcomas, and possibly breast cancer and leukemia. Although experts say that more research is needed, what's important for the home gardener is to play it safe. It is important to completely read directions.

Fertilizers aren't dangerous to handle, but chemicals used to control pests and weeds can be highly toxic. Used incorrectly, pesticides can poison not only people but also kill off beneficial bugs and contaminate the soil and groundwater, experts say.

Before you bring out your chemical arsenal this year, experts suggest asking yourself several questions:

• What is the problem in the garden?
• Is it a weed, an insect, or a disease?
• Is the problem serious enough to need a pesticide?
• What is the safest pesticide to use, and when should it be used?

Does your lawn really need a fertilizer? Homeowners can get a soil test done before laying down any nutrients. Soil kits are available at gardening centers and county extension offices and tell you whether or not your lawn needs a fertilizer and, if so, what kind.

Too much fertilizer can make your grass grow too quickly and develop a weak root system. And fast-growing grass means extra mowing time!

You can also go overboard on fertilizer for flowering plants. Too much fertilizer will encourage the plant to grow more leaves—and cut back on flower production. More growth also means more pruning, and thus more yard litter to dispose of.

If you decide to use a pesticide or herbicide, experts say you should first zero in on the problem: What kind of weed is it? What kind of insect? What kind of plant is the insect attacking?

One product is not right for every problem. A chemical that works on tomatoes may not work on eggplants, even though those two vegetables are closely related.

Timing is also critical. If you're trying to control dandelions, make sure you use the herbicide at the right time of year. Too early or too late in the season may not be effective.

Some chemicals may require that you water the plant after applying the pesticide, to make sure that the chemical gets into the soil. Others may need dry conditions.

The experts also stress safety precautions when using any of these chemicals. Wear rubber gloves and long sleeves to prevent getting the chemical on your skin. You may also need to use a respirator, a hat, or foot protection. Leather gloves or hats should not be used because they can absorb chemicals.

Use separate spray systems for herbicides and pesticides, so that the residues don't mix together.

Mix only enough of the pesticide to treat the problem. Dry pesticides can be stored safely for a season, but liquid pesticides must be treated as hazardous wastes and disposed of through a county hazardous waste program. Never pour them down the drain.

Never carry a pesticide in the passenger area of your car, or place it next to food items in the trunk. Never store the chemicals in anything other than their original containers to prevent possible poisoning.

Mulching keeps down weed growth, especially for annual plants.

For pest control, an example of a nonchemical approach is a method used for tent caterpillars. When all the caterpillars are in the tent, cut out the tent.

Check with your garden center or extension office for more ideas on nonchemical alternatives to pesticides.

Another approach is vigilance. Pull out weeds as soon as they appear, and pick off bugs as soon as you spot them on plants.

Once you've identified the garden problem, gardening experts recommend buying a pesticide based on its relative safety, its ease of use, and its effectiveness for the problem. Here is a list of toxicity warnings and their explanations, from the Florida Cooperative Extension Service:

• Danger-Poison. These are the most toxic pesticides and should be handled with extreme care.
• Warning. These are moderately toxic materials. They should be handled with care.
• Caution. These are slightly toxic materials that are still poisonous. Handle as you would any poison—carefully.

The Florida Cooperative Extension Service offers these tips for safety when using pesticides:

• Use a 1- to 3-gallon handheld sprayer, and check with plain water before filling with pesticide, looking for leaks or a plugged nozzle. Do not use a backpack sprayer because it can leak onto your back.
• Be especially careful when mixing a pesticide. Always have another adult in the area in case of an accident. Follow the label directions precisely. Have water, soap, towels, and a hose on hand in case of a spill. Mix only in a well-ventilated area.
• Keep other people and pets away when applying the pesticide. The label will tell you whether children and pets should be barred from the treated area.
• Clean the applicator and sprayer thoroughly after use.
• Immediately after applying a pesticide and cleaning the applicator, wash your clothes in hot water with a strong detergent. Do not wash them with other clothing. Take a hot shower and wash your hair.