Expert: Kenneth Joergensen - 8/7/2004

Question
So if I use an organic fertilizer such as Ringer, do I need something to control insetcs/pests?  What should I use and how often?

In Orlando Florida, Chinch bugs and fire ants are a big problem.  I don't have any specific problems myself (only in the house 3 months) but I like to do some preventative maintenance.

I was going to just do what the Scotts reccomends on the back of the bags and fertilize about 4 times a year (even though they reccomend 5 andwith different types) until going the organic route.

Thanks or your help :-)

Answer
Organic lawn care is a good idea.

When it comes to keeping bugs at bay, especially chinch bugs which can be a great problem on st. augustine grass in southern florida, cultural practices, including proper mowing, fertilization, and irrigation, can greatly reduce the susceptibility of St. Augustinegrass to chinch bug infestations.

St. Augustinegrass should be kept to a height of 3 to 4 inches to ensure a strong root system, which will increase the grass tolerance against chinch bug infestations. Lawns should be mowed frequently enough so that no more than 1/3 of the leaf blade is removed at each mowing. Furthermore, mowing with a sharpened blade will reduce the stress on the grass, thus making the lawn less susceptible to chinch bug outbreaks .

Large applications of inorganic nitrogen fertilizers can cause rapid grass growth and heightened chinch bug susceptibility. Using a slow release fertilizer like Ringer is a good first step.

Moisture stress in lawns also encourages chinch bug infestations. So make sure you water regularily, but avoid over-watering. The recommended way to water st. augustine is to water infrequently, but deeply. Irrigate only after wilting begins, when the edges of the grass leaves start to curl. Less than an inch of water is usually sufficient to rewet the top 8 to 12 inches of the root zone. Excessive water and fertilization can cause a thick layer of thatch to accumulate directly above the soil surface. Thatch, a spongy mat of shoots, stems, and roots, provides a prime habitat for chinch bugs to feed and lay their eggs. If a significant layer of thatch covers a lawn, it may be removed mechanically by vertical mowing or power raking.

Since most chinch bugs have become resistant to moderen insecticides it is better to use cultural initiatives to keep them away from the lawn, and the lawn healthy enough to withstand some damage.

Note: a deep layer of thatch may prevent insecticides from reaching the root zone.

If you notice browning, several insecticide applications may be needed, but as mentioned, they are not always effective. There are various products on the market, including Scott's, but applying them preventiatively is not a good idea.

Before resorting to insecticides, make sure you have identified that it is indeed chinch bug damage.

My recommendation is to fertilize your lawn regularily using a low release fertilizer, water infrequently, but deeply, and mow the grass 2.5-3" tall.