How to Make a Snowball Plant Change Colors

From Pink to Blue

• 1

  Test your soil pH to determine by how much you will need to increase its acidity -- lower the soil’s pH -- to achieve a color change.

• 2

  Lower soil pH naturally -- by 1 point -- and slowly by working 2.5 pounds of peat moss, 5 pounds of well-rotted manure or 14 pounds of compost into the top 12 inches of soil in a 1-square-yard area. Perform this soil amendment in winter when the shrub is dormant; you will need to gently remove then replace the plant.

• 3

  Work elemental sulfur into the soil to a depth of at least 6 inches as another way to change pH slowly. In sandy to sandy-loam soils apply 0.8-pound per 100 square feet to reduce soil pH by 1 point. In heavier loamy or silty loam apply 2.4 pounds per 100 square feet.

• 4

  Incorporate iron sulfate into the soil as a much faster alternative, which will start changing soil pH within a few weeks. In sandy to sandy-loam soils apply 4.8 pounds per 100 square feet to reduce soil pH by 1 point. In heavier loamy or silty loam apply 19.2 pounds per 100 square feet but split this into four applications at least four weeks apart. Water frequently to prevent soluble salt buildup.

• 5

  Use commercial soil-acidifying fertilizers, such as Miracid, to temporarily lower pH. Dissolve 1 tablespoon of Miracid or a similar product per gallon of water and saturate the root area. Reapply it every two weeks.

From Blue to Pink

• 6

  Test your soil pH to determine by how much you need to decrease its acidity -- increase the soil’s pH -- to achieve a color change.

• 7

  Apply dolomitic lime to increase soil pH, following the product instructions. How much you apply depends on the soil type -- clay soils require more than sandy soils -- and also on how big the pH change needs to be.

• 8

  Work wood ashes into the soil as an alternative but in any year do not add more than 2 pounds for every100 square feet of planting to avoid potassium overload, which can interfere with the uptake of essential nutrients.