cambece
Full Member
Posts: 11
Joined: Wed Jul 19, 2006 6:04 pm

Hydrangea color

Can the color of Hydrangeas be changed with soil additives or is the color purely a genetic thing?

GreenBayMike
Full Member
Posts: 48
Joined: Tue Jul 25, 2006 1:08 am
Location: Green Bay, WI - Zone 5a/4b border

Colored (non-white) varieties of hydrangeas can be changed from blue to purplish to pink depending on the acidity and availability of aluminum in the soil. There are several posts on this site relating to this information in more detail.

In the simplest of terms:
More acidic and aluminum available = blue flowers.
More basic (alkaline) and less available aluminum = pink flowers.

It is hard to maintain a purple hydrangea - you can keep them at one extreme to the other, but its hard to balance for purple. Most soils tend to have available aluminum so fighting the aluminum can be hard. Use Aluminum Sulfate to maintain available aluminum and slight acidity to keep them blue. But be careful when adding aluminum sulfate, because too much is a bad thing! Hydrangeas tend to be pastel in color and the depth of color you can obtain is limited.
-Mike
From the Frozen Tundra

cambece
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Posts: 11
Joined: Wed Jul 19, 2006 6:04 pm

thank you

Flowerpots
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Joined: Tue Oct 03, 2006 4:07 am
Location: Melbourne, Australia

Yhe blueing agent you can buy, when do you add to the soild and how long does it take to work ??

opabinia51
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Posts: 4659
Joined: Thu Oct 21, 2004 9:58 pm
Location: Victoria, BC

Blueing agent would be something like (in a so called organic form) pine needles or other acidic leaf from your area. You can also buy little acidic pellets.

GreenBayMike
Full Member
Posts: 48
Joined: Tue Jul 25, 2006 1:08 am
Location: Green Bay, WI - Zone 5a/4b border

The blueing "agent" I use is Aluminum Sulfate, which can be purchased at any good nursery or landscaper. It's about $4-6 for a 4# bag.
-Mike
From the Frozen Tundra

Flowerpots
Full Member
Posts: 41
Joined: Tue Oct 03, 2006 4:07 am
Location: Melbourne, Australia

Thanks got some over the w/e and have starting to blue the odd one here and there

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