Here are this week’s gardening questions and answers, provided by Parker County Master Gardeners. To submit a question, send it to firstname.lastname@example.org. For more information about Parker County Master Gardeners, or to become a member, call 817-598-6096 or visit www.pcmg-texas.org.
I have large, round areas turning brown in my lawn. What should I do?
Brown patch is caused by a fungus. Cooler weather combined with rain or excessive watering creates ideal conditions for this disease.
Brown circular patches with a yellowish smoke ring of withering grass at the edge will grow larger as this disease spreads. Unlike Take All Patch, Brown Patch will have a scattering of green blades of grass within the affected area.
This disease is easily controlled by using good lawn watering and mowing practices, as discussed below. If you choose to treat, use a fungicide containing pentachloronitrobenzene and carefully follow label instructions.
The blades of grass in my lawn have dark spots on them, and the grass is dying. What should I do?
Leaf spot is caused by a fungus that is present in all lawns. Fungus becomes problematic when grass receives too much water, leaving it too wet for too long.
This fungus first appears as oval gray spots on the blades of grass. As it progresses it may spread throughout the crown and roots of the plant. Tiny black fungal spores develop, and fungus then spreads to other blades of grass.
Repeat infestations can lead to widespread loss of your turf grass. This disease is easily controlled by using good lawn watering and mowing practices. If you choose to treat, use a fungicide containing mancozeb, myclobutanil, pyraclostrobin or propiconazole and carefully follow label instructions.
Healthy habits for your lawn
Grass should be mowed frequently and at the recommended height for your variety of grass. Mowing too short or removing more than 1/3 of the blade at a time will promote disease. Never mow when grass is wet. Fungal diseases are spread by foot traffic and mowing. When mowing diseased grass, catch grass clippings and dispose of them.
Water infrequently and deeply during early morning hours. Watering in the afternoon or late evening is problematic. Grass that is freshly fertilized is particularly susceptible to disease. Fertilize only as recommended for your variety of grass, at the right time and in the proper amount.
When reseeding, choose varieties that are resistant to fungal disease. Plant a blend of resistant grasses to reduce the chance of loss from disease in the future. For a thorough discussion of lawn care in Texas go to http://aggie-turf.tamu.edu.