Summer Planting: pH readings
Is your spring garden, now that you are harvesting the fruits of your labors, overgrown with giant weeds? If you compare the weeds health to your vegetables you may think that there is a difference in fertility, or maybe a difference in plant needs.
Let us start with making seed starting soils as demonstrated in the latest video about commercial fertilization. Commercial potting mixtures have an average of potential hydrogen (pH) less than 7 on a 1 to 14 scale. This is good for most maturing plants and even works well, as we demonstrated in the video for starting seeds. But the more advanced secret is do you know the exact pH of your soil mixture?
Most plants want a pH measurement of 6.5 to 6.8 on the scale. Some plants are really fussy and want either a higher alkaline scale, such as brassia (cabbage types) just bordering on pH 7, or others in the acid range such as Stevia.
The advantage of bed growing is that each bed can be adjusted for a specific plant’s pH, ensuring maximum fertilizer intake and healthy growth. If you have a plant that is growing painfully in the wrong pH measurement no matter how much fertilizer you mix, the plant cannot absorb it.
To get a better idea of this, let us assume you are a small market gardener specializing in tomatoes. You set out a hundred plants and you expect maximum production for those tomatoes will be sweet, so sweet that people for miles around will come to buy your tomatoes. To do this we must measure the bed or growing area with an inexpensive pH meter and adjust accordingly to the scale of growing tomatoes.
Since tomatoes are either hybrid, or heritage, from Russia, or China, these plants may have slightly different pH ideals. This is where you select the best genetic specimen in the garden bed, of the different varieties, and test each plant. Assuming that you keep a record in your Gardener’s notebook, you will be ahead of the game.
PH, the acidity-alkalinity scale of 1 (very acid) to 14 (very alkaline), with 7 being neutral.
You probably will not get so picky as stated above and for home use, just adjust the soil for tomato growth at 6.5. I do think, for the purposes of discussion you become aware that each indexed number becomes exponentially larger as we run up the scale. It does not seem like a big difference between 6.5 and 6.9 but that is 3X more in absorbsion that the plant may or may not desire. You have to keep the plants happy.
You can purchase an inexpensive pH meter in garden centers, or as I do at Amazon.com. Meters are hand size with a movable meter scale in numbers. They are offered in dual wire probes, three wire probes and single wire probes. No matter which probe you choose they all measure electric current in the test sample. I prefer the model with an electric connection via a short 12” or so wire between the meter and the probe, as it is easier for me to read. (Old eyes, and such). Otherwise I have used a dual probe directly connected to the meter to read the sample. They all work.
If you do not want a meter you can purchase a liquid chemical test kit-which I recommend for testing separate Nitrogen, Phosphorus and Potash fertilizer values for critical work. These liquid chemical kits also test pH. These small kits can be inexpensive, averaging $25.00 or a thousand dollars. They all do the same thing.
Forgetting all else you can purchase at the drug store a litmus paper roll that will also measure pH.
Let us return to the pH meter for about $15.00 with two prongs. You cannot just stick it in the ground. You have to prepare the ground (soil samples) first.
In the garden bed or big flat conventional garden plot you first have to till up the space selected. You will take several readings. Tilling up mixes old organic residues (which have fertilizer and pH values) along with the master gardener (earthworms) contributions.
You will take small plastic bags, fill with soil but scooped from a spoon. Your hands have acid residue.
Each bag is labeled with a marking pen where the sample was taken. I use a basic broad checkerboard pattern for the garden, or for the beds, 80’ X 5’ a diamond shape each 5’ in length. All this is recorded in your Gardener’s Note Book for comparison in years to come. Plus it keeps you busy and in touch of changes trending.
You will need a gallon of pure pH7 water, distilled water is cheap and the best maybe a dollar. You can take a sample of the soil and place it in a clean cup. Pour in water to make a thick soupy glop. Now, insert the pH meter probes and you will have conductivity between the probes wires giving you a reading. Record this as to location in the Gardener’s Note Book map.
Since the probes become coated with residue continued insertion into samples would be inaccurate. Borrow a small sample of steel wool from the kitchen dishwasher person and
Wipe each probe shiny and it will give you an accurate reading. Record this.
I might add that most soils going into the cup are lumpy. I have a small screen sifter I made to sift it fine.
All this reading sounds like a big project but it is not. The above is for meters, litmus paper, or chemical readings.
To adjust the pH readings is to add dolomite limestone powder as a sifted spread over the area to raise the pH 1 point at a time. The general rule is 1lb, per hundred square feet. To lower the pH to a more acid level you have to be very stingy. Use your screen sifter and add sulfur at the teaspoon rate per 100 square feet. Acidity is very difficult to lower and once you lower it, to adjust up is a pain.
Measurement of the limestone pH change takes about a week or two to be correct. Acidity adjustment with sulfur can be tested the next day. When dusting with sulfur it will burn the eyes with discomfort. Wear eye protection. Wash hands twice.
Both dolomite and sulfur must be tilled into the soil.
Live long and prosper. God Bless.
COPYRIGHT: Back2theLand.com, all rights reserved. 8/10/2014