Your Browning Lawn - To Water or Not?

Meander through any Hamilton County neighborhood today to take note of the varying degree of browning of the non-irrigated lawns. We can speculate why some lawns have fared better than others (higher mowing heights, proper seasonal fertilization, better soil conditions, etc.) but exact reasons remain unclear. One major factor affecting that effects lawn survival during extended dry periods is supplemental irrigation or rainfall in your area. Lets look at how a homeowner knows it is time to take the next step and irrigate their lawn to prevent permanent damage from these dog days of summer.

Most lawns in our region primarily contain cool-season grasses that grow best when the air temperatures are between 60 and 80 degrees F. Well cared for mature grasses can tolerate extended dry periods. When these dry periods are coupled with higher temperatures, there can be additional physiological stresses which can be irreversible.

Water should be applied only when lawns show signs of moisture stress. During this time, one may notice a bluish gray tint to blades; footprints that remain some time after walking; and wilted or curled leaves are indications that it is time to water. At this point a delay in watering can result in permanent damage unless you have decided to allow the lawn to go dormant.

Established lawns should be irrigated with 1 inch of water every week to ten days to keep it growing actively. I prefer early morning watering because it reduces the risk of disease, water loss through evaporation, and improper water distribution. If you decide to allow your lawn to go dormant, irrigate every two weeks with 1/2 inch of water.  This strategy allows the turf to go dormant but will keep the plant crowns hydrated during drought. If you need some help determining whether your lawn is dead or has transitioned into dormancy, click here for a good article with pictures to help your decision.  

Exerts taken from the following Extension Publications.  Click links below for more information. 

Purdue Turf Program: Summer Drought Info

Home Lawns During Drought

Tar Spot on Maple

This week I have had numerous calls about black tar-like spots on maple trees throughout Hamilton County. The spots are not truly tar, they are in fact fungal leaf spots that are becoming noticeable that likely started forming after the rainy start we had earlier this summer.

Tar spots on maples are caused by fungi in the genus Rhytisma. Although tar spot disease may cause premature defoliation of leaves, seldom are they detrimental to the overall health of infected trees. Tar spot diseases are best managed by raking and destroying fallen leaves since the fungi overwinter on leaves.

There are a few other common foliage leaf infections found on maples, click here to read more about these diseases.

Annual Native Tree Sale

Hamilton County Soil and Water Conservation District is currently taking orders for their  annual tree sale. The organization is offering over 30 varieties of native trees and shrubs to enhance your landscape. Their website also offers an abundance of resources to help you decide with plant is right for your individual situation. For more information, click here for the 2015 Native Tree Sale website. All orders and payments must be received by Thursday September 3rd.

Weather Extremes Can be Tough on Landscape Plants

If for no other reason than usual weather, 2015 will go down in the history books as a year to remember. We have experienced abnormal rains and extended dry periods within a few months. Over the past few weeks, Hamilton County homeowners have been calling the Purdue Extension office about stress symptoms on oak, maple, and other tree species. Some of the samples received include leaf scorch - the browning of leaves - branch die back and premature defoliation.

Click here to read the full article from Purdue University.