browser icon
You are using an insecure version of your web browser. Please update your browser!
Using an outdated browser makes your computer unsafe. For a safer, faster, more enjoyable user experience, please update your browser today or try a newer browser.

Projects you can start this year, for next year. Idea #3 = Plant Projects

Posted by on June 9, 2012

If you know how to do a project AND you know you want to, or need to, do one for next year – why not start one now?

It is the perfect time to start a plant-themed science fair project because there will be sufficient time for the plants to grow by a measurable amount. Plant projects also automatically earn extra points for effort because they are an example of a project that could not have been done the night, or even weekend, before the due date.

Typically a plant project’s DEPENDENT VARIABLE will be some indicator of growth. That could be height, weight, surface area, volume (e.g. for a succulent), and/or the number of blades, leaves or flowers. If you start with seeds the dependent variable could be the number (expressed as a count or a percentage) that germinate and if you start with plants it could be the number that survive or the number that die. Color could also be selected, but remember that color is a QUALITATIVE variable and the top projects almost always have QUANTITATIVE dependent variables.

The INDEPENDENT VARIABLE is a much more difficult choice. Plant projects usually suffer from a lack of creativity because there are only so many ways you can water or light a plant. Very common examples include watering plants (seeds/seedlings/plants) with tap water, rain water, distilled water, bottled water, carbonated water, salt water, pond water, flavored water, etc. or other common liquids like coffee, milk, soda, tea, juice, bleach, etc. Also, a project that shows up at almost every fair I have ever judged includes growing plants under different colored lights. I highly recommend trying to design a creative project that stays away from these ideas.

To design your own plant-themed science fair project, try one of these strategies to find a creative topic:

1. Think about your desired end result:
• Do you want to ENHANCE plant growth to increase yield? This result might help certain regions of the world grow more crops. What aspects of growing a plant could be systematically manipulated to increase production of the targeted food?
• Do you want to REDUCE plant growth to eliminate a specific species? This result might help with weed control or removal of invasive species. What apspects could be systematically manipulated to discourage growth?

2. Think about plants in their environment:
• Are you interested in PLANT-ANIMAL INTERACTIONS? Remember there are some observational studies that are allowed using vertebrate animals such as birds, squirrels, bats, etc.? What aspect of the plant attracts or detracts animals? Can you suggest and test a suitable alternative?
• Do you wonder how plants discourage insects from eating their own leaves (did you know plants have “weapons”)? Research PLANT-INSECT COEVOLUTION and PLANT DEFENSES. Find one that interests you and test how effective it is.
• Did you know some plants compete with each other (for space, light, water, pollinators, etc.) while others help each other grow (symbiosis)? Look into ALLELOPATHY. How could allelopathy be used to help farmers?

3. Focus a project on the development of a part of the plant:
• Plants have many parts: Fruits, seeds, leaves, stems, shoots, roots, flowers, etc.
• Research PHOTOTROPISM, HYDROTROPISM, THIGMOTROPISM – Ask: How does the plant “know” where to grow? Can you outsmart the plant by altering an aspect of its environment? What practical application might this have?

4. Focus on a unique plant type
• Grasses are easy to grow, but mostly boring. Research: Mosses, Ferns, Vines, Epiphytes – what are their UNIQUE ADAPTATIONS that faciliate their success? What would you expect to happen if you manipulated their environment?
• Carnivorous plants; Research their unique ecology and ask: is there food preference among or within carnivorous plant species?
• Aquatic plants; Research their unique adaptations and ask: how much does that adaptation contribute to growth?
• LICHENS (OK – these are not plants, but if you live near or have access to the woods – you could do a very original projection on lichen growth and ecology)

4 Responses to Projects you can start this year, for next year. Idea #3 = Plant Projects

  1. Lauren Dougherty

    I am trying to help my son do a science project with succulents. Any ideas on what we can do? We started to propagate them and now need to plant them soon. Was thinking of planting in different types of soil, and using direct light versus indirect light? I know you said to try to stay away from this type of project. Please help

    • Dr. Maille Lyons

      I think this project would be a great idea, just remember to only vary one variable at a time and make sure you have at least three propagations per treatment.

  2. irma


    my daughter would like to do a science project on terrariums but she is stuck on the “pose a question” portion of her science fair project. We’ve thought of topics like, water usage of a succulent garden vs grass, water cycle, watering plants with little water and conserving water. I don’t know how to help her and i am unsure if the questions I would pose are either too difficult, not science oriented or too easy. can you help us?

    • Dr. Maille Lyons

      Have her focus on things she can measure, so that she has a quantitative dependent variable.

      If she has a long time, then it could be growth of the plants inside the terrarium. Remember that you will need at least six terrariums (3 for the control and 3 for whatever aspect she will change to see if it has a measurable effect on the dependent variable) and many succulents grow relatively slowly.

      If you are using sealed terrariums, you could put thermometers inside and measure temperature or you might be able to measure water generated… but that might be difficult.

      Ask her what she likes most about terrariums… maybe that will help her find a question.

      What is the effect of (one thing she is interested in) on (something she can measure).

Leave a Reply

Your email address will not be published. Required fields are marked *