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Reducing pH for blueberries – the easy way.

The main requirement for growing blueberries is that the soil have a low pH. But how can this be done easily.

Well first we must define pH. pH is a chemistry term that describes a solution (soil) where there is either a greater amount of H+ ions (acid molecules) or OH- (basic molecules). For blueberries we want the soil to have a greater amount of H+ ions (acid molecules). When there are more acid molecules reactions happens that convert elements like iron, potassium and nitrogen into the right formulations and amounts needed by the plant. In fact blue berry bushes are unable to absorb needed iron without a greater concentration of acid molecules. This is often seen in the plants as yellowing of the leaves – which if left uncorrected will lead to the death of the plant.

In order to achieve a higher amount of H+ ions we have to add amendments. The 3 most effective amendments are Sulfuric acid (battery acid), elemental sulfur and aluminum sulfate.

It is possible to use Sulfuric acid – but it is dangerous to handle and if the correct dilution is not used your bushes will die a quick and painful death! It is used by experienced horticulturalists to quickly lower pH around large established bushes.

Elemental sulfur is the cheapest option. Elemental sulfur is acted upon by the bacteria in the soil and produce a safe concentration/dilution of sulfuric acid. This is an easy way to reduce pH when growing blueberries. Elemental sulfur can be applied to established plants but is most effective when added to soil – 1-2 months prior to the planting of blueberries. Add 1-2 lbs of elemental sulfur per plant area. Usually on elemental sulfur packaging recommended amount of sulfur per plant or planting area is stated. Elemental is best for larger planting areas.

Aluminum sulfate works similar to elemental sulfur where soil bacteria act upon the sulfur in aluminum sulfate to produce plant safe sulfuric acid. Aluminum sulfate is more soluble( mixes easily with water in soil) than elemental sulfur. Because aluminum sulfate mixes so easily with water it lowers pH quicker. Aluminum sulfate is most effective for smaller soil solutions (i.e. container planting). Aluminum sulfate packaging will recommend amount of aluminum sulfur to apply according to plant size and planting situation (i.e containers vs. raised bed)

So the easy way to reduce soil pH is to use Elemental sulfur for large planting areas and aluminum sulfate for blueberry container planting. Elemental sulfur is best when applied 1-2 months prior to planting. However both amendments can be used immediately on established plants. Always follow package recommendations. Note: It is also important to add organic items like pine bark and peat moss to soil bed when planting blueberries. These also help with increasing soil acidity.

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