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Continued issues with high phosphorous and alkaline soil in flower garden #878896
Asked July 26, 2024, 12:29 PM EDT
Ramsey County Minnesota
Expert Response
Thank you for your question. It has been referred to me.
I could not open the 2022 soil report. Could you please try sending it to me again. Based upon the 2024 report, I do not see anything that would be of significant concern. The pH and organic matter level are acceptable. Don't be concerned about the phosphate levels. These can be highly variable and can quickly fluctuate. The potassium level is also within acceptable levels. In short, I do not see much in the soil report that might be responsible for the poor performance of your flowers. For the time being, do NOT add any more potash. Hold off on the coffee grounds as there is not reliable evidence that it is beneficial. It certainly does not lower pH to any significant extent. It is very difficult to change soil pH. Addition of peat moss does help but don't expect a significant decrease in pH. I don't know what "acidifier" you are using. Could you please clarify this.
Could you please send me some pictures of your garden and the specific flowers that are affected. I think something else is going instead of soil issues.
Good morning, I have now been able to look at your soil reports for both 6/22/22 and 7/9/24. Let me try to summarize where I think we are at.
1). The phosphorous levels in 2024 were certainly higher than in 2022. However, I don’t think that you should be concerned about these levels. Soil phosphorus can vary markedly on almost a daily basis. I don’t believe that phosphate is negatively impacting your garden and plants.
2). Adding blood meal and peat moss are good things to continue. Don’t make further additions now (early August 2024) but do this around the first of September. Check the source of the peat moss. It should come from Canada. Work about three inches of peat moss into three inches of existing soil. Both your soil reports (2022 and 2024) suggest adding 0.15 pounds of nitrogen/100 square feet of your gardens. If you purchase blood meal at a gardening center, look at the product label. You should see that it contains about 13% by weight nitrogen. This means that in every pound of blood meal, there is 0.13 pounds of nitrogen. Close enough to the 0.15 pounds of nitrogen. So for every 100 square feet of your garden, add about 1 pound of blood meal. Water it in well. See:
https://eising.ca/mixing-peat-moss-with-soil/
3). At this time (early August 2024), do nothing about the potassium levels. They are currently acceptable.
4). The pH levels (7.5 in 2022 and 7.4 in 2024) are slightly on the high side but not seriously. If you do the peat moss additions that I suggested, and possibly repeat in spring 2025, the pH should drop slightly. Forget about coffee grounds and any other acidifier. They will not be necessary if you add peat moss.
5). If you do the blood meal (think nitrogen) now, I don’t see any reason for further additions of fertilizers. Maybe this fall, in addition to the blood meal, you may want to work into your gardens some fallen leaves. These will add to the nitrogen content of your soil.
I would greatly appreciate your thoughts regarding these suggestions. Thanks for consulting with us.
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