Geranium Root Growth: (Laura Silverman)


Laura Silverman, 7th grade Science, Mulholland Middle School

Research Question and Hypothesis

Will root growth hormone increase the number of centimeters of root growth on a geranium clipping in water over a 4 month period of time?


Cell Biology

7.1. All living organisms are composed of cells, from just one to many trillions, whose details usually are visible only through a microscope.

f.    Students know that as multicellular organisms develop, their cells differentiate.


7.2. A typical cell of any organism contains genetic instructions that specify its traits. Those traits may be modified by environmental influences. As a basis for under­ standing this concept:

a.  Students know the differences between the life cycles and reproduction methods of sexual and asexual organisms.

Experimental Design

A geranium clipping is placed in water in a window sill with indirect light from October through January.  Root growth will be monitored each month and root length will be measured with a centimeter/millimeter ruler.

Independent variable

The independent variable is the amount of growth hormone.

Dependent variables

The dependent variable is the root growth.


We will be studying the length of root grown (dependent variable) as a function of time (independent variable) with various amounts of root growth hormone (series). 

Constants and Controls

The constant will be the amount of sunlight and temperature, and the control will be using no root growth hormone.


A plastic or glass container for about 200 - 400 mL of water for each group.  Labels for each group and a clipping of geranium branch for each group.  Root growth hormone.


Have the students hypothesize the length of the possible root growth and make a graph in their lab book.  Check every month on the growth and graph the growth in their lab book.  Compare their findings to other groups with more or less growth hormone.

Sample data and graphs

See above, will add photos of actual student lab books.

Analysis & Conclusions

The root growth will probably vary from plant to plant regardless of amount of hormone yet should show overall increase  as an average.  Also the days will get shorter but will be the same for all groups.  The conclusion will most likely be that root growth increases with more hormones.

Photographs and Movies

Here's the clippings...


Here's the root growth that occured after a couple  of months for some groups.  Other groups had their branches turn to mush.  We will see how the growth is after the new year, which will be month 3.

root growth

Root growth hormone:

hormone bottle

YouTube Video:  Time lapse of root growth...


Here is a site explaining this lab for a science fair project:

Here is where you can buy the root hormone online from amazon: