Color Change in HydrangeasAc

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HYDRANGEAS??

Hydrangea macrophylla is a the species of hydrangeas more commonly known as ‘bigleaf’.

The Bigleaf Hydrangea:• Can be found in local

gardening centers• Is a common decorative

plant• Grows best in morning

sun & afternoon shade• Produces blooms that

are pink, blue, or a mixture of both.

Blue or Pink?

Aluminum is the variable which changes the pH level in soil. The presence of aluminum lowers the pH level (blue blooms), while the lack of aluminum keeps the pH level higher on the scale (pink blooms).

pH 5.0-5.5 pH 5.5-6.5 pH 6.5+

SETUPLeft: Base - Pink - Dolomitic LimestoneCenter: Control - Pink & BlueRight: Acid - Blue - Aluminum Sulfate

METHODS→

MATERIALS ↓

1. Sun and shade2. Record pH levels3. Water with

solutions

3 Hydrangeas (pink)pH MeterDolomitic LimestoneAluminum SulfateTap Water

www.gandermountain.com/

Changes of pH Level in Soil8 Weeks

Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Week 8

Acid 6.7 6.5 6.4 6 5.9 5.5 5.3 5.2

Base 6.6 6.6 6.7 6.7 6.8 6.6 6.7 6.7

Control 6.6 6.4 6.5 6.4 6.3 6 6 5.9

1

3

5

7

9

11

13

Chart Title

pH le

vel

Fina

l Res

ults

Left is the acidic

(blue)right is the alkaline

(pink).

Control plant has both blue and

pink blooms.→

Sources Cited1King, Judith. "Changing the Color of Hydrangeas." All About Hydrangeas.

Web. 2 Mar 2010. <http://www.hydrangeashydrangeas.com/colorchange.html>.

2King, Judith. "Planting and Transplanting Hydrangeas." All About Hydrangeas. Web. 2 Mar 2010. <http://www.hydrangeashydrangeas.com/planting.html>.

"Solutions." Modern Biology. Austin: Holt, Rinehart, and Winston, 2005. Print. "pH Preferences of Plants." GreenTerraFirma.com. 2007. Web. 3 Mar 2010.

<http://greenterrafirma.com/pH-preferences-of-plants.html>. "Life of the Garden Party." Southern Living. May 2010: 78-83. Print.