At the start of gardening season, I was confident this year would be no different than any other in regard to tomato blight. I made a point to calm fears about a return of the late blight epidemic that plagued gardeners last season.

But all this rain has changed my tune. Late blight has been confirmed in Beaver, Indiana, Somerset, Cambria, Blair and Westmoreland counties. It might also be in Allegheny County. It's not time to panic, but for the first time in years I've sprayed my plants just to be safe.

The key to battling any fungal disease is prevention; plants need to be treated with a fungicide before any signs of damage. As an organic gardener, I reach for two products.

The first is a copper-based fungicide, which is what I sprayed on my tomatoes at first but reticently. Even though copper is organic, it can negatively affect the environment, most notably by killing aquatic life. Keep it away from streams and ponds and follow the label instructions.

The other product is Bacillus subtillis, a beneficial bacterium that is sold under the brand name Serenade. There are other strains under different brand names. It's completely safe for the environment, it doesn't affect beneficial insects and it lets tomatoes be harvested the same day of spraying. But it needs to be applied often, every four to seven days.

Bacillus subtillis attacks the fungal disease pathogens, prevents spores from germinating and fights off late blight, hopefully, but the jury is still out on its effectiveness. That's one of the dilemmas of being an organic gardener -- trying to save the tomatoes and the environment.

Chemical gardeners have a host of products that will fend off blight. I would advise using the one that is the least toxic. Be sure to follow all safety precautions when applying and harvesting tomatoes. Whatever you use, it's more cost-effective and easier to buy a concentrate that's mixed and applied with a sprayer, especially if you have more than a couple of plants.

Last season, a front-page story advised readers to pull out the plants infected with late blight. I had countless voice mails the next day from concerned gardeners who did just that. The problem was only about half of them had late blight; the rest had early blight or another less-threatening fungal disease common to tomatoes.

It's an important lesson to learn: Diagnose the problem first before taking action, and don't panic. Early blight starts at the bottom of the plant, yellowing leaves and creating brown spots, and then gradually works its way up the plant. It's a common disease, and plants can outgrow it during the season.

Remove the infected foliage and apply fungicide as warranted. It's important not to spread the disease from one plant to the other while removing leaves. Disinfect tools or your hands between plants with a 10 percent bleach/90 percent water solution. Many years I've just let the early blight do its thing and harvested more than enough tomatoes. It's a soil-borne disease, so mulching is a way to keep fungal spores from splashing up on the leaves.

Late blight, on the other hand, is fatal to tomatoes and is airborne. After a freeze, it's gone, but it can survive in living tissue, which usually means potatoes left in the ground. If volunteer potatoes pop up in a garden where late blight was detected last season, they need to be destroyed. Either bag them and send them to the landfill or burn them.

Late blight is identified by black or brown patches on stems, leaves and/or fruit. If late blight is found on a plant, it needs to be destroyed. There's no recovery from the disease. Only tomatoes and potatoes are affected by the disease; other crops aren't infected.

It's too early to tell if late blight will take hold in our gardens this season, but with the advent of rain, late blight sightings and painful memories of a crop lost last year, it's better to be safe than sorry. Beth Gugino, assistant professor of plant pathology at Penn State, says that if you think you have late blight, you should contact your local Penn State Cooperative Extension office so they can confirm the disease.