QuestionQUESTION: We live in far northern Minnesota. Our lawn is three years old. We put-in a sprinkler system this summer because of dry weather the past two summers. Several areas of the lawn turned brown and the grass has died or is dying. We have fertilized twice, and I intend to do it again soon. What has caused this problem, and what to do about it? We have a very gravely, rocky soil.
ANSWER: If these brown areas have cropped up after you put in the irrigation system, then the problem is associated with the sprinkler system; coverage is inadequate either because heads are not matched or overlapped enough or the system needs to be run longer each time. If you apply fertilizer and irrigation does not reach any area, the grass will be 'burned'. Recalibrate the system to obtain a 25% overlap, match the heads (note 1) and time the system to run long enough to apply half inch of water each time (note 2).
If the brown grass matches the pattern of watering then the water source (lake or well) might be contaminated.
Notes: 1. Matching heads means simply that if one head is doing a full circle while others are doing a half circle, then the full circle head ought to have double the gpm of the half circle heads because it has to cover twice the area in the same time.
2. Stop the system if water starts to run off on to the sidewalk or street. If the timing is not enough, run the system later to make up.
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QUESTION: I don't think it's the sprinkler system. It seems as if it is some type of fungus....or such. It is very patchy, and doesn't seem to allow grass seed to grow in those areas. The grass and lawn around it seems to be doing fine. We're talking about several patches about 20 square ft. in area(each).
Answer A lawn problem is not a question of what you or I think it is; it is caused by factors which come under the headings:
1. Cultural: what we do and how we do it. Mowing, irrigating, fertilizing, spraying and the like.
2. Environmental: freezing, flooding, shading etc. You can also include here things like fluid spills, parked vehicles.
3. Pests: a) animals like nematodes, insects and rodents.
b) plants like dollar weed, crabgrass etc.
4. Diseases: on lawns these are caused by fungi chiefly e.g. brown patch. Also caused by virus e.g. St. Augustine Decline. Bacteria cause diseases on grasses not associated with lawns e.g. leaf scald on sugar cane (yes, it is a grass). On other plants e.g. tomatoes, they cause wilts.
When you ask me about a plant problem, I try to determine the cause from clues which you give. From there it becomes a joint effort; together we eliminate the causes, one by one; starting with the simplest. Between us we arrive at a solution which you will have to undertake. It will cost money and time. I empathise with that because I am poor and busy.
Therefore I try to be as thorough and accurate as I can.
Now, can you tell me that it is definitely not a watering problem because you have checked it out?
