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grassypants

Grey Leaf Spot

grassypants
16 years ago

I noticed under a different post " Mother Nature is killing my lawn" that I also have Grey Leaf Spot. I mow at 4 inches, and haven't needed to water my grass since we have been getting so much rain here. I apply corn meal every month because my St. Augustine was prone to Brown patch and Take all root rot diagnosed by the Natural Gardener here in Austin with a microscope, now it looks like I have Grey Leaf Spot...what can I do?

Comments (13)

  • dchall_san_antonio
    16 years ago

    Take a look at my post in reply to Mother Nature is killing my lawn. If your symptoms are the same as his, you don't have gray leaf spot; you have an iron shortage. Use greensand at 40 pounds per 1,000 square feet to resolve the issue. Give it 3 weeks to work.

    Check with the Natural Gardener and he will confirm.

  • skoot_cat
    16 years ago

    Im not so sure! I agree that the photos show signs of an Iron deficiency by the yellowing, but they show much more, especially in the close up (photo 3), Mother Nature is killing my lawn post.

    No where on the WWW was I able to find anything about leaf spots associated with an iron deficiency. This spotting appears to be Gray Leaf Spot. Yes, its hard to tell as many of the disease look the same

    Nitrogen deficiency can also cause yellowing of the leafs.

    Here is a link that might be useful: Gray Leaf Spot

  • grassypants
    Original Author
    16 years ago

    Photo #3 in Mother Nature is killing my lawn post looks like my grass in some small areas.

    I have checked out the link and my St. Augustine is similar to plate #17 in 3 area's that are 2 x 4. What organic choices do I have? I noticed only fungicides.

    All of my cultural practices are fine and I already put down corn meal every month.

    I will put down the greensand as Dchall has recomended. Should I just wait and check back in 3 weeks after spreading the greensand?

    I have changed to organic this year and my St. Augustine is looking great! I just have these small area that I am still working on.

    On another note my neighbor and I are having a contest to see who's lawn looks the best Labor Day weekend He is spraying his lawn green and I am only using organic. Needless to say I will have lots of questions.

    Thank you!

  • skoot_cat
    16 years ago

    What organic choices do I have? I noticed only fungicides.

    In your case, I would say do nothing. From what you have stated, you are doing everything correctly. As with most diseases, Gray leaf spot appears to be a water related.

    The greensand is a good idea, it an excellent Organic source of potassium and other trace elements. It will really green up your yard, which will also be good for the contest.

    Hold up, wait a minute, I stand corrected. I just found this from the UF-IFAS Extension. "Potassium (K) seems to be an important component in the prevention of diseases, perhaps because it prevents plant stress." Looks like we have a winner (Greensand).

    You have a tough contest on you hands, especially since this is you first year in organics. Remember, with organics/grains it takes time. Your are building the health of your soil.

    What time of day, how often, and amount do you water?
    How much rainfall have you received?

  • grassypants
    Original Author
    16 years ago

    This will be a tough contest!

    For the I can't remember how many weeks we have recieved over an inch of rain a week, so I have not needed to water since mid-May. I was lucky enough to put 20pd/1000ft of corn meal down before all the torential(sp) rain a few weeks ago.

    When the soil does dry out, I will water 1 inch in intervals with the sprinkler system. I water my St. Augustine when it starts to show the first signs of stress. Or should I water every 7 days in the hot summer without the first signs of stress? I always been a little confused about that. I water at 4:AM.

    I'll put down the greensand ASAP. These 3 areas are really thin, not thick like the rest of my lawn. Any suggestions?

  • skoot_cat
    16 years ago

    These 3 areas are really thin, not thick like the rest of my lawn. Any suggestions?

    Compost, spread it about a 1/4 to 1/2in thick, Then use a push broom to sweep, or lightly rake it off the grass blades and down into the turf and then water in. Water these areas frequently by hand for the next couple weeks.

    As for watering; Frequent (daily), light waterings promote shallow root systems that do not result in healthy turf. If your lawn can go more than 1 week without water, Great. If it cannot, water longer next time. You should Let Your Lawn Tell You When To Water. Lawns should be irrigated when 30 to 50 percent of the lawn shows signs of wilt. Unless rain is forecast in the next 24 hours.

    What else (besides CM) are you feeding your soil?

  • grassypants
    Original Author
    16 years ago

    "What else (besides CM) are you feeding your soil?"

    I have only been putting down corn meal every month since April because of the massive brown patch and TARR that I had (20pd/1000). Since those 2 diseases thrive on N, I only used corn meal for total fear of it taking out my entire yard! UGH! Now, that I think my grass/soil is in better shape, today I put down the Alfalfa meal/pellets that I had at 20pds/1000ft along with coffe grounds I get from my Independent coffee shop. I was hoping the root/growth hormones associated with Alfalfa might help my case. Also, I noticed on one of your previous posts that it does have potassium which will help until I get the magic green sand I read so much about!

    Your right I need to add the compost....

    What is your opinion of my previous post Alfalfa meal/pellets with ethoquin? Morpheus(sp)certainly made me feel more comfortable using it.

  • lou_spicewood_tx
    16 years ago

    If you want to win the contest, Corn GLUTEN meal will give you a dramatic green up or darker green. Unfortunately, they are expensive and messy (powdery stuff). The speadable granulated type is even more expensive in the range of 20 dollars for 40 or 50lbs. If you still want to try them, put them down 3 weeks before your contest.

    I've never heard of those diseases thriving on nitrogen. I thought it had to to with too much water.

    Have you put down a thin layer (1/4th inch) of compost on troubled area? Corn meal won't work unless there is trichoderma fungi to feed on corn meal and grow in large numbers enough to overwhelm harmful fungi.

    Soybean meal is another good organic fertilzer. It has 2nd highest amount of protein behind corn gluten meal but apparently it doesn't have same affect as far as giving you the darkest green color. you might want to try 30lbs per 1000 sqft to see if you'd get a boost on green up from extra protein and still be cheaper than CGM.

    Try Lowe's for greensand. They have the best price by far. Try mixing with lava sand 50/50 to break up greensand and be a lot easier to spread by hand. Greensand tends to take forever to dry out enough so I've never tried using rotary spreader plus it would take forever with 80lbs per 1000 sqft.

  • skoot_cat
    16 years ago

    I've never heard of those diseases thriving on nitrogen.

    Gray leaf spot and brown patch diseases are water related. It is suggested that you Avoid readily available forms of nitrogen such as soluble liquids or quick-release nitrogen sources just prior to or during these periods. Instead, use slow-release nitrogen sources.

    You should be safe in applying any of the grains listed above. I would go with the SBM, since you just put down alfalfa. Say, the beginning of August. The CM you've been applying is excellent for fungus control, but is a very week fertilizer as you probably know.

    Be careful how much (even organics) you put on your yard. The microbes in your soil are only able to process so much at a time. In the first year you would be safe with monthly applications of grains/organics.

  • grassypants
    Original Author
    16 years ago

    I've never heard of those diseases thriving on nitrogen.

    From the research I did on Brown Patch and TARR (which of course I deleted all my bookmarks from Texas A & M and a lot of other places, so I can't find them now to make my point!)it was due to compacted, alkaline soil, moving too short and the use of excessive high nitrogen fertilizer and of course water for the brown patch. Which is odd because we did not have a sprinkler at the time, really didn't fertilize at all but we were mowing to short and had compacted and what I believe to be alkaline soil.

    I found a study by 2 profs from Texas A & M who treated lawns with Take all Root Rot in Dallas by applying 1 cubic yard of peat moss/1000Sft which changed the PH of the soil. This controlled the TARR so that it did not spread. In another area they applied 40pds/100sft of Hu-More manure compost. The Hu-More compost was less effective over time, which surprized me. But then maybe it was the quality of the compost that effected the study. I will try to find this link for you.

    From this study I put down the peat moss as directed (I know most everybody here dislikes peat moss), sprayed compost tea on all my poor St. Augustine and applied 20pd/1000 corn meal which I found from this forum and The Dirt Doctor. The difference is amazing. I wish I had pictures for you. 3 weeks and BAM just like everybody said. The corn meal is weak, but let me tell you it did wonders on my grass. But maybe my St. Augustine was just that awful!

    I will put down greensand mixed with lava sand as Lou recomends to spred by hand.

    I will put down the compost in the really spindly thin but finally green St. Augustine.

    I was worried about applying SBM & CGM because I thought the high protein value which equals high N value that it would promote too much top growth and not enough root growth? Am I wrong??? I do want to win my contest and have the best yard on the street! Looks like I'll be busy 2nd week of August. :)

    Thank you for taking the time to answer my posts.

    Great link by the way, really liked the section on drought stress important in these parts you know.

    ~grassypants

  • skoot_cat
    16 years ago

    I was worried about applying SBM & CGM because I thought the high protein value which equals high N value that it would promote too much top growth and not enough root growth? Am I wrong???

    Yes and no!

    The rapid top growth mainly applies to synthetic fertilizers where the (N)pk values are very high. example (30-3-3). Synthetics gives your grass/plants NPK whether they need it or not. Overdoing it will have predictable long term results. The grass will not be able to develop the root system it needs to support that canopy.

    With Organics, your feeding the soil. You provide your lawn/soil with a slow acting, beneficial source of nutrients. You will not get explosive top growth with the organic/grain approach. Well, you might with the CGM, but I've never used it, too expensive.

    With what you've mentioned above, you are applying an excellent balance of food for your microbes to enjoy.
    Corn Meal- excellent fungus control/ mild fertilizer/ fungal food
    Alfalfa- typical NPK 2-1-2 plus high availability of trace minerals/ bacterial food
    Greensand- contains 6% total potash/ minerals/ very slow acting/ great for overall plant health
    Soy Bean Meal Typical NPK 7-2-1/ fungal food

    Once you've applied the above amendments, I would hold off until your last feeding in fall. Do not feed your lawn in the winter months, as S.A. is a warm season grass. If your worried about the Brown Patch returning, you could continue applying CM monthly at 10lbs/1000sqft.

    Check out the link below, Great organic Fert, plus not very expensive. I'm going to use this for my fall feeding.

    Here is a link that might be useful: luscious lawn & garden 3-1-5

  • skoot_cat
    16 years ago

    Heres another, its from Colorado State University. Very good info about NPK/nutrients and uses of grain/organic ferts

    Download Organic Fertilizers 234-pdf.

    Here is a link that might be useful: Organic Ferts

  • lou_spicewood_tx
    16 years ago

    Grassypants,

    I can see how you are concerned about nitrogen being too high. My advice is forget you've learned about chemical. Chemical and organic are two very different things. You should get a book called Teaming with Microbes by Jeff Lowenfels. Barnes and Nobles might have it otherwise Amazon or other websites (google it) will have them. Very informative for beginners.

    your schedule should look like this..

    Mid Feb - Soybean meal and cornmeal (20lbs/1000sqft each)

    Mid May - soybean and corn meal

    Mid august - Soybean and corn meal

    Mid November - soybean and corn meal

    You could put down 40lbs of greensand per year.

    Optional - unsulfured molasses/apple cider vinegar mix using ortho dial sprayer every time you put grains down. 4oz mix per 1000sqft, i think at 2 oz setting.

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