Beating Insect, Disease Pressure in The Garden

February 12, 2018 - When we care for our landscape and gardens around our homes, we often must fight a number of pests. 

Pests that include insects, fungus, mites, viruses, animals and more. 

And there is a great deal of debate on what is the best way to fight such pests. We can treat with conventional methods, organic pesticides, home-brew recipes or even simply do nothing at all and let the fittest survive!

Too many folks get all wrapped up on what is the best way to “kill” off a pest when there are several other methods to avoid, repel, or simply prevent pests in the garden. 

The technical verbiage of using the least toxic approach to pest control is Integrated Pest Management (IPM). IPM can be applied to lawns, flower beds, vegetable gardens and many other areas. 

Step one is selecting the right plant for the right location. More subtle than using a tropical plant in our zone that clearly gets too cold, take a look at where the sun and shade occur. Sun-loving plants will do poorly is heavy shade. Also study the soils. Dry climate or xeric plants won’t do well in a water-logged soil. 

Pecans and peaches are notorious for needing full sun and well-drained soil, but we often seem bent on planting them in yards where they are doomed to fail because conditions don’t match their needs. The result is a stunted and disease-ridden tree that bears poorly. 

Secondly, select disease resistant plants. Every rose gardener is quite familiar with the fungus, black-spot. Our climate in East Texas favors the growth of black-spot like none other! Be sure to research and plant roses that have been proven resistant to this common pathogen. 

Next, water at ground level, not over the top. Roots are the part of the plant that will pull up moisture. Spraying the entire plant will make it wet in an already humid region. Fungal disease will certainly thrive in areas that are kept moist. The common culprit here are gardeners get off from work in the afternoon and go outside to water shrubs or vegetable plants with an overhead spray. 

Indeed, all plants need water, but be sure to give it to them thru drip irrigation or at least with a bubbler or other ground delivery system. Water droplets on the leaves serve no good purpose other than signaling to every fungal spore that they have a place to start. Keep water applied to the soil so that the roots can absorb it. 

When you see dead plant material, go ahead and remove it. Especially this time of year as we come out of our recent hard freeze, prune out and discard the dead plant tissue. Any old tissue that is not living is a safe harbor for insects and disease. Sharpen up your pruners, cut it out and get it out of the landscape!

Be sure to soil test for nutrients needed. Surely this is the oldest gardening advice, but one that can still certainly pay off. How does one know what nutrients are lacking? How does any gardener know what to add? The big three nutrients in complete fertilizers (nitrogen, phosphorous, and potassium) can vary widely. Too much (and not enough) of any of those will lessen the strength and resilience of your vegetation. 

Proper watering is also a major factor. I believe we kill as many plants by drowning them as die from drought. As mentioned earlier, plants vary on their tolerance to moisture stress. 

Finally, inspect your plants regularly for insects, disease or other problems. In large farms, producers scout the fields for all manner of pestilence before it can get out of hand. Look under the leaves of your tomatoes for the hornworm. Study the spots you see on your roses. Know what is happening and keep track of where and how it spreads. 

Lane Dunn is the County Extension Agent for agriculture and natural resources for Shelby County. His email address is jldunn@ag.tamu.edu and he can also be reached at 936.598.7744