Hydrangea (Hydrangea macrophylla)

I love the idea of Hydrangeas in the garden and am constantly being asked where they will grow best in the garden.

Where to plant your Hydrangeas in your garden:
When planting give them room to spread. All hydrangeas will bloom and grow well in morning sun and afternoon shade. No Hydrangea will grow well in heavy shade or under a shade tree. The blooms will be sparse and not develop well.

Choosing the colour chemistry:
If you want the pink and lavender blossoms grow in neutral soils and in slightly acidic soil, they’ll be deep blue. If you live in a hot climate, it is unlikely you will ever see a “true red”
much lime is added to the soil, one can only achieve a very deep or dark pink, 
but not a true red. 
It is much easier to change a hydrangea from pink to blue than it is from blue to pink by adding aluminum to the soil one can change a hydrangea from pink to blue. Changing from blue to pink by removing aluminum from the soil f the soil naturally contains aluminum and is acid (low pH) the colour of the hydrangea will automatically tend toward shades of blue and/or purple.

The choice of fertilzer will also affect the colour change. A fertilizer low in

Phosphorus and high in potassium is helpful in producing a good blue color (25/5/30 is good. Potassium is the last number).Superphosphates and bone meal should be avoided when trying to produce blue.
To obtain a blue hydrangea, aluminum must be present in the soil. To ensure that aluminum is present, aluminum sulfate may be added to the soil around the hydrangeas. Water plants well in advance of application and put solution on cautiously, as too much can burn the roots.To make the aluminum available to the plant, the pH of the soil should be low (5.2-5.5). Adding aluminum sulfate will tend to lower the pH of the soil. Another method for lowering the pH is to add organic matter to the soil such as coffee grounds, fruit and vegetable peels, grass clippings etc.

WHITE HYDRANGEAS can not be changed to pink or blue by the grower.


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