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South Dakota Home Garden: Pests and Disease
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Erik Helland of Landscape Garden Center talks Pests and Disease in the Garden.


Today we'll talk about pests and diseases. The important thing to remember about pests and diseases is that they will develop when plants are typically stressed. The opposite of stress is making sure everything's healthy. And so the things that we want to remember is that when we have healthy plants, they've been watered frequently and consistently.  They're not being stressed by different droughts or different watering habits.  They've been fertilized, or they have the specific nutrition to be healthy. That is one of the most important things. 


Insects will attack plants that are unhealthy. By the time you see an insect attacking a plant, it is probably too late to react.   You're seeing that plant or that insect, they've been coexisting for quite some time. And so basically what you want to do is, okay, what stage of this bug are you dealing with? How do I treat that? And then, how do I make sure that I'm treating that for into the future? 


Now, if you know that you have consistently had issues with a specific plant or a plant in an insect, then what we recommend is doing a systemic insect control. Systemic insect controls are the best, and it's the easiest way to handle it. And that is done by having an insecticide that you are putting into water, a water-soluble condition.  Then, you pour that around the base of the plant. The plant actually absorbs the insecticide. When the insect attacks the plant, it is met with the insecticide. 


A lot of times when we have people come in and say, "Hey, what is this?" It's almost too late. So now it's like a, "How do we fix this?" "What type of artillery are we going to use?"   That is when you're going to have to get into the sprays and try to get a contact spray or a contact insecticide to spray onto the plant and onto the insect.  That way you take out that insect, then that way they don't lay their eggs for the next cycle of life. 


Japanese beetles have been hitting the Sioux Falls area, the Southeast South Dakota region very hard over the past couple of years. One of the things to do with those is to identify what you're dealing with. The Japanese beetle has got an Emerald green, shiny green back. The lady bug is orange and has dots on the back.  Once you identify that you do have the Japanese beetle, then the best thing to do is to try to collect those Japanese beetles and then destroy them. Because the last thing we want those to do is to be able to lay more eggs for the following year.  If we do a good job one year, it should help the following year. 


There are many beneficial insects that I can think of. We want to keep the bees around and hopefully the bees are out there and being very active. Ladybugs will take out aphids. Wasps are really good.  Some wasps will actually use other insects as their host. When the egg hatches it is using the insides of that insect as its food to continue. So, wasps are good. You just want to have them nesting in the right place. 

So now here's the other thing about diseases. When we're talking about diseases, diseases also happen to plants that are being stressed.  If plants are healthy, they will be able to resist pests and also resist diseases. So that's why we stress to make sure that we're water thoroughly, we have well-drained soil, and that the plant has everything that it needs to survive and thrive. When you want to run across certain plants, if it's been cool and damp, we might run into more powdery mildew and then we might have to spray. But at the same time, in not all cases when you have pests or diseases, does it call for a reaction.


In most cases, the best way to handle all of your pests and diseases is by sanitation. 90% of all of the diseases and insects are in the debris that have been left over from the year prior. Clean up your garden and around your landscape very well, remove all of the dead leaves and all of the materials that could actually let things live there.  That really helps to eliminate your pests and your diseases. Once you get done with a cleanup around your landscape or your garden, is time to mulch. Mulch is really good for a couple of different reasons, it'll help you through a drought and keep the soil cooler. And then it will also help from the standpoint of suppressing weeds, which then are not competing with the plants. 

I'm Erik with Landscape Garden Centers and keep it growing.