pH measures the acidity or alkalinity of your soil and can make the difference between happy, healthy and luscious plants and a wilting, high maintenance, unsatisfying garden. Knowing the pH of your soil is essential for anybody beginning to grow in a new area. Luckily, testing the pH of your soil is simple.



The pH scale runs from zero to fourteen with seven being the marker for neutral soil. Soil with a pH lower than 7 is acidic soil and soil with a pH above seven is alkaline. Most plants are happiest in neutral soil; it provides them with the essential nutrients they need. However, there are a few acid loving plants such as blueberries, rhododendrons and azaleas that grow best in soil with a pH of between four and a half and five and a half plus some plants such as delphiniums, clematis and privet will flourish in more alkaline soils.

How can you test the pH of your soil?

Soil pH testing kits are readily available but for those who don’t require an especially specific reading you can save some cash by using basic kitchen items.

One sure fire and very simple way of testing the pH of your soil is by using baking soda and vinegar. You’ll need two samples of soil from your garden in separate containers. Add vinegar to one of the samples; if it fizzes it means your soil is alkaline. If there is no fizz, add water and then baking soda to the other sample and if this fizzes it means your soil is acidic. If neither of the samples fizz you can conclude that your soil is probably a neutral pH around seven.

If you wish to know further the specific pH of your soil, use a red cabbage. Chop it finely and add it to boiling distilled water. Let it simmer for roughly ten minutes before draining the cabbage pieces, leaving just the now violet coloured liquid: this liquid will roughly have a neutral pH of seven.

Now comes the really clever part. Add a couple of spoonfuls of soil to a few inches of your violet coloured liquid and leave it for about half an hour. When you return the colour may have changed: the colour of the liquid indicates the pH of your soil. If it remains a violet or purple colour your soil is a neutral pH of seven, pink will mean your soil is acidic and has a pH of between one and seven, whilst alkaline soil with a pH of between eight and fourteen will be indicated by blue or green colours. The brighter the pink or green colour is, the more acidic or alkaline your soil is.

How can you change the pH of your soil?

Most gardens will have soil with a pH of between six and a half and eight pH and as a general rule dryer areas are more alkaline wheras moist areas tend to have more acidic soil. Depending on what you plan on growing, you may wish to add either sulphur or limestone to your soil.

If you wish to make your soil less acidic then limestone is what you need. I’d recommend dolomitic limestone if you can find it; it’s less expensive than the pelletized pulverized kind and contains magnesium which is as essential for plant growth as calcium is.

For making your soil less alkaline you’ll need to get some sulphur. Usually it only comes mixed in with other nutrients such as magnesium or ammonium. Remember that for best results you should till any additives to a depth of between four and six inches.

Whether it’s sulphur or limestone you wish to add to the soil you’ll need to make sure you do it properly. A drop spreader is an economical and efficient way of achieveing good results. It’ll spread your sulphur or limestone evenly, but you will still need to go back and make sure everything is worked into the soil afterwards.

If you have a large garden this could seem like a lot of work. It may take a while, but it is one hundred percent worthwhile. The key to healthy, happy plants and establishing a productive, good looking garden begins with the soil. Get it right and you’ll reap the benefits in no time at all.

Posted in: Gardening Tips