4/5/2020 – With the KEL meter checked the pH of the original yard garden (not the area added today up to the rail fence) and was surprised to find it from 3.5 to 5.5. The area tilled to the fence today was 6.2 to 6.8. That must be why nothing Mary, Piper, and Olivia planted has come up.
Why did it get so acidic? Maybe because I spread 50 lbs of cottonseed meal to add organics. Cottonseed meal is spread around blueberries to make the soil more acidic and maybe that is what made the big change.
Epic Gardening’s article on cottonseed meal recommends: “Before planting, a good rule of thumb is 2-4 lbs per every 100 square feet of soil. If your soil is particularly poor, you can go as high as 8-10 lbs.” So, their max is to spread 10 lbs/100 sf and at the rate over our 315 SF would have been 31.5 lbs. BUT, I spread 50 lbs.
Plan to return to a normal pH.
Using advice from Baker Lime’s site here and from following SF Gate’s article, Raising pH; When pelletized lime is used to raise pH, the application rate depends on the current soil pH and the desired pH…. The following approximate application rates will raise pH from 5.5 to the optimal 6.5: for sandy soil, 25 pounds per 1,000 square feet; for loam, 75 pounds per 1,000 square feet; and for clay soil, 100 pounds per 1,000 square feet. If the current pH is even lower (near 4.5), these rates should be multiplied by a factor of about 1.8. Sandy soil, for example, would then require about 45 pounds (25 x 1.8) per 1,000 square feet.
- Original Garden is 9’x35′ = 315 SF
- Need to raise the pH to 6.5 from 3.5/4.5 or 2-3 points
- To raise it 2 points we need 2 X 50 lbs per 1,000 SF (averaging for a sandy loam)
- Our 315 SF space is approximately 1/3rd of a 1,000 then, if the pH was not so low, we should spread about 2 times 1/3rd of 50 lbs or about 34 lbs.
- But, we need to include the 1.8 multiplier for very low pH so that is 1.8 X 34 = 61 lbs.
- Relocated all the seedlings planted a week or so ago back to their pots. Left the onions. Every one of them immediately perked up.
- Spread, tilled, and watered in well, about 40 lbs of pelletized lime over the 315 SF. That is less than what was calculated above but it seemed like a lot. Plan to check it monthly and track the pH returning to normal.