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A Guide To Soil PH

16:36 Mon 24th May 2010 |

When planting new flowers and shrubs planning ahead is very important. One vital thing that you will have to establish is the PH of the soil that you are going to be working with.


What is PH?


PH is one of those things you might remember from science lessons when you were back at school. We aren’t dealing with lemon juice and litmus paper now though. With soil, PH refers to the amount of hydrogen present in it. This rating defines whether a soil is:

• Acidic with a PH of 1 to 7
• Neutral with a PH of exactly 7
• Alkaline with a PH of 7-14.

The acidity or alkalinity of a soil basically decides what can be planted in it. Consequently testing soil before you plant in it is crucial. If a plant is placed in the wrong soil type it will die as a result of higher vulnerability to disease and less absorption of nutrients.

 To analyse your soil you need to get your hands on a PH testing kit. A cheap one of these can generally be picked up for under £10. They provide a quick and convenient way of establishing a soil’s PH. Just make sure you follow the instructions which come with it.


Which Plants Suit Which Soil Types?


The PH requirement for the majority of plants is fairly close to neutral; often ranging from around 5.0 to 7.0. At this level they find nutrients easiest to absorb. As most British soil’s PH generally fits into this band the majority of plants have little trouble growing anywhere. Yet there are exceptions:


Acid Soils

Many Plants prefer slightly more acidic soils. Examples of these are flowers like the Daffodil, Fuschia and Pansy. Also fruits like Strawberries and Raspberries grow best in these conditions


Alkaline Soils

Many other plants prefer high alkalinity soils. For example the Crocus and Snowdrop can easily survive in PH 8.0 soil. As can fruits like the Blackberry and vegetables like the Leek and Asparagus.


Changing a Soil’s PH 

If you wish to grow a certain plant but your soil’s PH does not match its rating then all is not lost. A soil’s PH can be raised by adding agricultural lime or quicklime. This generally increases PH by around one unit making it better for higher acidity-soil plants.To lower a soils PH you can add products like rock sulfur or certain fertilisers.

Unfortunately changing PH is a fairly involved process with short term results. Therefore doing it on a large scale is a bad idea. The best way to grow plants which have a different PH to your soil is to go out and buy an acidic or alkaline compost and grow them on a smaller scale. For example if you wanted to grow a plant in acidic soil peat compost is a good option.

With this in mid you should be able to plot out your perfect garden.

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