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tnflowerlover

Soil Test Help?

Carolinaflowerlover NC Zone 7b1 hour ago

So, I did my solid test as recommended by various people due to rudbeckia not blooming. Here is what I got. I am researching, but I would be grateful for insights. I noted how old the boxes are in (). For obvious reasons, it was recommended I use only N fertilizer in all areas and some lime in a few areas. I wonder what causes the phos and potassium to be so high and if I need to worry. Something is definitely wrong, as I have several plants that take 3-4 years to bloom or do not bloom after one year or are stunted.

I use Miracle-Gro soil in raised boxes, so very little or no clay is in there...except the yard sample, which is all clay with leaf mulch/soil dumped on top due to no topsoil.

I rarely fertilize. I do use willow/pin oak leaf mulch every fall and remove some in the spring (I leave most of it down in the hydrangea box). I used Miracle-Gro 2-3 times between April and June or July, but that was it.....I will not use it anymore. I occasionally use fish fertilizer on a few plants. I do use Holly-Tone every spring for hydrangeas. Otherwise, no fertilizer and no compost (I am trying to get a compost pile going).

I used my hands to get the soil (except the yard) and rinsed very well between samples, so there should no contamination.

I called my county ag office...nice, but not much help. Any help understanding how it is this year and what I should and should not do would be great. :)

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Other (3-4 years old): Phos 108 K 96 pH 5.4

Hydrangeas (3-4 years old): Phos 510 K 91 pH 4.8

Front yard box (6 months old): Phos 73 K 87 pH 5.6

Lawn: Phos 99 K 158 pH 6.8

Comments (12)

  • 11 years ago

    Phosphorus is not very leachable (in contrast to N) so it tends to build up with continuous additions of compost or fertilizer. I think there is a limit beyond which it can be detrimental but I can't tell you exactly where that is. Someone will chime in. The best way to deal with that is to not add any more. Cut down on compost additions (use something low in P like peat moss or shredded bark if you need to refill the containers). If you need N use only fertilizers with little or no P. The lawn has fairly high K also, so if you fertilize, use urea (29-0-0 or something like that) instead of the 29-3-3 that is often found.

    I assume the county ag extension were not the ones who did the test for you, or they would have/should have provided recommendations.

    TNflowerlover Zone 7a thanked toxcrusadr
  • 11 years ago

    It was the state Dept of Ag that did the test. I called my local office. They can be hit or miss in their knowledge, unfortunately.


    Thanks for for the tips. I did wonder if I should not do the leaf mulch, since the box with the best Phos/K reading is the one that has never had any leaf mulch (it is the newest box). The box with the highest Phos reading is the one that rarely has the leaf mulch removed. My fear is that I will lose plants without that covering....but, something needs to give. (Sighs)

    I was going to buy blood meal since it only has nitrogen, but it said it would lower acidity? Maybe it was just that kind. I am going to use fish fertilizer and bought a hose end sprayer for it. It is 5-1-1....not high in nitrogen, either, but I have loved it in the past. I am looking for a good iron spray, too, since I read high Phos can inhibite iron uptake.

    Thanks for pointing that out about the lawn. We will look for something besides the winterizer we were going to use.

    Thanks, again, for the thoughts. I am open to more from you or others, too. :)

  • 11 years ago
    last modified: 11 years ago

    For most of the year soil tests in North Carolina can be obtained for free. http://www.ncagr.gov/agronomi/sthome.htm

    Topsoil is, quite simply, the top portion of soil, the top 4 to 6 inches of soil (depending on the definition) so the only thing your North Carolina clay soil might lack is organic matter. Clay soils need organic matter to separate the soil particles so plant roots, moisture, and nutrients can flow or be found, otherwise the clay will hold the moisture and nutrients and not let the plant roots have them.

    Miracle-Gro potting soil is not soil but is a soilless mix and requires, most often, some fertilizer applications since the materials used do not have any readily available nutrients to feed the plants.

    Perhaps this publication might be of some help, http://content.ces.ncsu.edu/a-gardeners-guide-to-soil-testing.pdf

    kimmq is kimmsr

  • 11 years ago
    last modified: 11 years ago

    I had not heard that about blood meal lowering pH (it actually increases acidity rather than lowering it). I would think the effect would be small since you don't use a whole lot of blood meal and it's mostly organic matter (i.e. weak acids). But I don't know the mechanism of the effect, maybe it has something to do with the iron content rather than organic acids. In any case it might be best to avoid on all your low pH beds. Urea is another alternative that is N-only, or ammonium nitrate or sulfate (but check the pH effects of these before using). Also, you could add lime...

    TNflowerlover Zone 7a thanked toxcrusadr
  • 11 years ago

    Kim, I only have clay in the lawn....rest are raised boxes with Miracle Gro garden soil. I see I didn't specify it was garden soil, not potting soil. :) My test was through NC, where you linked to. I had not seen that booklet p, though, and I see it explains the other minerals, so I really appreciate that. Thanks!

    GG...yep! I agree on all accounts. Thanks for the explanations. I hate messing with clay, but I know many people do so quite well. I definitely do not need to use MG anytime soon, though. Lol


    Tox...thank you, again. I guess it was that specific product. I will look for the urea instead. Thanks!

  • 11 years ago

    If you lower a soils pH you increase the acidity. If you have a soil with a pH of 7.0 and add sulfur that pH will drop and you have increased that soils acidity. Blood Meal does lower a soils pH or increases the acidity of that soil.

    Miracle Gro Garden Soil is not real soil but is a soil amendment and is meant to be added to the mineral component of soil. This product is not meant to be used in pots or containers (think raised beds) but is to be mixed into soil.

    For gardengal http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/newsroom/features/?&cid=nrcs143_023543

    Perhaps the above linked article might be of some use.

    kimmq is kimmsr

    TNflowerlover Zone 7a thanked kimmq
  • 11 years ago

    Wow....I somehow missed that about the garden soil. Not sure if those directions were there 4-5 years ago, or maybe I didn't read them. Lol Thanks for pointing that out. I do not regret solely using it, b/c my soil is awful and nearly impossible to mix stuff in (we wanted to do it for the new box this year). Plus, the yard (pretty much just regular dirt) results are fairly similar to the box results. However, it is good to know for the future. Thanks!

  • 11 years ago

    I'm rather surprised that a soil report from an extension agency just gives numbers and doesn't say whether they are high, optimum or low. And they should be more helpful in terms of what to add (or avoid adding). Not that we mind giving advice, I'm just a little mystified about the service you got.

  • 11 years ago

    The report did say they were "above optimum." I just was looking for help on if they are only kind of bad or really bad (since the bar graph only goes to 100), if I can do anything to lower them, etc. I should have phrased that better in the original post. Too bad I cannot edit.

  • 11 years ago

    No edit button? I seem to have one on each of my posts. Not sure why I would and you wouldn't.

  • 11 years ago

    I have one on each comment, but not on the original post.