When it comes to pests, think before you spray

This time of the year is when people start to notice damage to their plants from a variety of insects and diseases.

The first rule of diagnosing a plant problem is to identify the plant, and then you can begin to identify what caused the problem.

Always, no matter what, always identify the cause of the problem before getting out the pesticide spray.

In the past, people used to call our Horticulture Helpline and tell us they have a problem and they have “sprayed everything” but nothing seems to help.

Don’t be this gardener! Identify the source of the problem and then, even before picking a pesticide, determine if it’s even necessary.

For instance, I have written about tomatoes and the various leaf diseases you might see.

Once you see the symptoms of the disease, it’s too late to spray.

You may be able to spray the new growth with a fungicide to prevent further damage — but the leaves that are damaged won’t recover.

When you get to this time of the year and see damage, the question that begs to be asked is, “so what?” At this point in the season, will a pesticide make any difference?

If you don’t do anything, will the plant die or will it come back again next year?

For instance, if you have a linden tree and you live in the Miami Valley, chances are you are seeing a lot of damaged leaves.

The damage is done, the beetles are pretty much done feeding, and why spray when it wouldn’t really make a difference at this point? If you are going to spray for Japanese beetles you have to start early in the season when they first arrive.

Let’s say you have a large oak tree and you notice that the leaves have holes in them. If you can’t find the critter that is causing the damage, don’t bother using pesticides.

And even if you do find a critter, think about the time of the year. They may do a little more damage to the leaves, but it’s unlikely that they will completely defoliate a tree.

Let’s say they eat all of the leaves today. I still wouldn’t worry, because the tree will soon lose all of its leaves anyway, and will likely come back next season just fine.

My point is, don’t use pesticides unless you think it’s necessary. Think about timing and the life cycle of the pest.

The later in the season you see damage, the less important it is to take action.

And if you do decide to take action, always determine exactly what is causing the problem before using a pesticide.

I truly believe that gardeners are getting much better at this than when I first started my career. People are thinking more about the plants, problems, and solutions before spraying.