It's a nasty rainy day in Highlands. Granted, it is much needed because the month of April, we only received 2.9" of rain during the entire month. Combine that with the lower than normal humidity and wind, there were some challenging days trying to keep sod and turf alive. Even our monthly average rainfall total for 2021 is low, at 8" per month.
Rainy days allow us time to do other things that fall by the wayside when it's sunny and our time is spent mowing turf. Rainy days are a perfect time to feed the soil, or fertilize greens with a variety of nutrients that need to be irrigated into the soil. Two such products we are putting out today is standard Gypsum and KCS 0-0-18, from the Plant Food Co. The pelletized gypsum is a greens grade prill, that can be found at any home improvement center. Gypsum is a product that adds Calcium and Sulfur to the soil but doesn't have an effect on the soil pH like dolomitic limestone would.
I get this question a lot... "How much lime should I put on my yard each year?" The answer is, I don't know. The only way to truly answer that question, is looking at a soil report analysis from the yard in question. Dolomitic Lime or Calcitic Lime are products used to raise the soil pH. In Highlands, our native soils can be rather acidic, so applying lime to your lawn won't necessarily hurt, but putting out 1 or 2 bags over a 5,000ft2 lawn will do very little other than give you a little bit of calcium. Without getting into the specifics of the chemistry and math involved, raising the pH of a soil often takes a lot of lime over time. One bag per year isn't even going to move the needle. It also takes the soil-lime reaction over 6 months to occur. It's not overnight.
It's also worth noting for entertainment value alone, that the pH soil reaction that occurs after applying lime, is the exact same reaction that occurs in your belly, after you eat a 'Tums.' Both products (Tums and Calcitic Limestone) are the same thing...calcium carbonate. The carbonate ties up Hydrogen ions (which is the acid) giving off H2O (water, of course), CO2 (carbon dioxide) as well as freeing up a calcium amendment for your soil. Ever wondered why you burp after eating a Tums... that is the CO2 byproduct of the same reaction. So yes, you can throw Tums on your lawn to effectively raise the pH and you can also eat dolomitic limestone from the fertilizer isle at Lowes, to calm your acid stomach. While this is 100% true, I wouldn't recommend it. Not only will it taste bad, you might get cited for shoplifting.
So what if you're soil pH is perfect in the ideal range of 6.5-7.0 but you still want a good, inexpensive calcium amendment? That's where Gypsum comes in. As I said above, Gypsum offers a calcium amendment without the change in soil pH.
And finally, why does the soil pH matter anyway? The acidity or alkalinity of a soil will impact what other nutrients are available to the plants growing in that soil. You can see by the graph below, that most all nutrients are most readily available when the soil pH is within the 6.5-7 range. A lot of times, when a particular stand of turf, like a yard, isn't meeting the expectation of the homeowner, the condition of the soil can play a huge part in that.
If you are ever struggling with your lawn, never underestimate the benefit of a soil test.
