Question
What is killing my lawn? It was fine in the spring, and now this summer, it is looking dead in patchy spots.
Answer(s)
There are several diseases that could be affecting your lawn during the hot summer months. Brown patch (Rhizoctonia) causes irregular brown patches on the lawn. Fading (Curvularia sp.) also causes irregular dead areas. Both of these diseases can spread rapidly during high temperatures, especially when turf is stressed. Brown patch can infect the entire plant if conditions are suitable or can cause a crown and root rot. Both pathogens survive on dead leaf blades and debris that reside in the thatch layer of the lawn.
The best way to manage both diseases is to improve the health of your soil and turf. When mowing during the hot summer months, keep the grass height at 2 ½" to 3" to alleviate stress. Remove clippings to reduce sporulation on decayed leaves, and mow to a shorter height at your last mow in the fall, when the grass has stopped growing. Fertilize only in the fall.
An excessive thatch layer can contribute to disease development. Thatch should be kept at ½ ″ thickness so that water and air can penetrate to the roots. Aeration can improve air circulation to the root system. Be sure to use an aerator that takes soil cores out of your lawn. The machines that punch holes in your lawn only increase compaction. This should be done in the spring or fall when the weather is cool and provides a less stressful environment for your turf to recuperate.
Proper watering is very important. Ideally, water your lawn deeply about once/week when natural rainfall does not occur. Apply the water in the morning to allow the leaf blades to dry quickly. This reduces the moisture available for the fungus to develop and allows for better moisture retention in the soil. Infrequent and deep watering promotes root growth which supports the crown and leaves.
Other Questions In This Topic
- I have a 25-foot tall scrub oak that appears to be dying. If it is anthracnose that is killing it, can it be saved? There are some commercial, injectable products that claim success. Is it possible?
- What herbicide/killer do we use to eradicate "salt cedar" & cheat grass??
- Yesterday I applied "Scotts Turf Builder Plus 2 Weed Control" to my lawn. Unfortunately, I had the drop spreader set incorrectly. As a result I later discovered that I had accidently applied 4-5 times as much fertizer as specified on the bag. Will this damage the lawn? Is there anything I can do to prevent damage?
- What is anthracnose?
- I have a curly willow that was topped about four years ago. Now it needs to be trimmed. Can I cut the branches back to where they were cut last?
- I made the mistake of fertilizing my newly planted trees. I had heard that the salty, clay soil I have needs iron useable for the trees. I used chelated. Anyway two of the trees, a candian red cherry and a zelkova tree have dry crispy leaves on the north side of the tree. We have had very hot, windy weather. I have two other canadian cherries that look fine.
- What do the numbers on the fertilizer package mean?
- We planted a new yard with several pine trees this last Fall - including sub-alpine, a young cedar, douglas fir, and a couple of sequioa .... along with the traditional small conifer bushes. With the recent wind and the sensitivies of the sub-alpines and sequoia I wanted to be sure that I fertilized, etc., a needed (watered them a little today due to strong winds).