Your Soil Condition

Soil Condition

 

Last weekend I was approached by a member and asked how he could reduce the acidity of his soil. He had purchased a soil testing kit to check the pH of his soil and it indicated that his soil was acid.

So, sit up straight and pay attention whilst I try to explain in layman’s terms what the pH means and how to tell if your soil is acidic or alkaline.

I have always been of the view that if the crops I planted all grew, were heathy and tasted fine, then everything was ok.

To test the pH of your soil you need to buy a reasonably priced testing kit and follow the instructions.

Technically, pH is a gauge of the hydrogen-ion concentration (potential Hydrogen) in a substance. For the gardener’s needs, it is enough to know whether your soil is alkaline or acidic because certain nutrients can only be accessed by plants when the soil pH falls into an acceptable range and no amount of fertilizer is going to improve their health until the pH has been adjusted. Soil pH is a measurement of the alkalinity or acidity of soil. Soil pH is measured on a scale of 1-14, with 7 as the neutral mark. Anything below 7 is considered acidic, or sour, soil and anything above 7 considered alkaline or sweet, soil.

Most plants prefer a somewhat neutral pH, anything from 6.2 to 7.0. However, there are many plants that are more specific in their pH needs, such as blueberries and azaleas which like a very acidic soil, andlilacs and clematis that prefer a more alkaline soil. There are even some, like hydrangeas that change flower colour depending on the soil’s pH.

Generally speaking, if your plants are growing healthy, with no signs of problems, your soil pH is probably in an acceptable range. However, if your plants are looking stressed, discoloured, or not growing vigorously, one of the first things you should do is test your pH.

How to Correct Your Soil’s pH 

It takes time to change the pH of soil, often months, and it will need to be an ongoing process. Left alone, soil will eventually revert back to its natural pH. However, you won’t have to adjust all your soil, unless it is extremely acidic or alkaline. You can adjust just the areas where you are growing plants that need a different pH. For example, if you want to be successful with blueberries you need to plant them in ericaceous peat and water them with rainwater only.

Basically, the pH of acidic soil is raised by adding lime. The pH of alkaline soil is lowered by adding some form of sulphur (horse manure is just as good), How much to add depends on your current soil pH, the texture of your soil (clay, sand, humus) and what you will be growing.

Once you get your soil pH into an acceptable range, you will need to reapply either lime or sulphur on a regular basis, to keep it there. This is best done in the autumn or off season, so that the amendment hastime to work its way into the soil slowly, without harming plant roots. It’s also a good idea to re-test your soil about every 3 years, to see if adjustments need to be made. Of course, your plants will have the final say. If they are going well, it’s hard to argue for changes. Most soils nutrients are readily found in the soil provided that the pH level is within the 6 to 8 range. However, when the pH level rises, many nutrients (like phosphorus and iron etc.)  may become less available. When it drops, they may even reach toxic levels, which can adversely affect the plants.

Your plants will tell you if they like the soil they are growing in.

Just because you have got the pH of the soil correct doesn’t mean to say they do not need to be fed to give them that extra boost whilst growing. We have all looked at rows of fertilizer in the shop and wondered what is NPK and how do I know which plant wants what.

NPK is Nitrogen, Phosphorus and Potassium and the numbers on the label represent the percentage of each. For example, 20-5-5 mean the fertilizer has four times more nitrogen in it than phosphorus and potassium.

Nitrogen – largely responsible for the growth of the leaves of the plant

Phosphorus – responsible for good root growth and flower and fruit development.

Potassium – is a nutrient that helps the overall functions of the plant perform correctly.

Knowing the NPK values of a fertilizer can help you select one that is appropriate for the type of plant you are growing. For example, if you are growing leafy vegetables you may want to apple a fertilizer that has a higher nitrogen number to encourage leafy growth. If you are growing flowers, you may want to apply a fertilizer that has a higher phosphorus number to encourage more blooms.

That’s it. Science lesson over now go take a headache tablet and have a lay down.

On the plot.

This week the weather has been quite reasonable, and I am sure many of you have taken advantage of the little sun we had to get your plot in shape. Broad beans, Onions, Garlic and Peas are still doing well, as are my pots of sweet peas. Still picking Kale as Brussels as and when we need them. I have cut all my Autumn Raspberries down to ground level and given them a good covering of home-made compost. I fill my compost bins with horse manure and leave for 12 months and the end result is a fine compost alive with worms.

Dennis Flaherty

Allotments secretary