To grow a plant by vegetative propagation and understand why it might be advantageous to do so.
This lesson is the second in a two-part series on plants. In these lessons, students research and carry out reproduction in plants and come to understand that most plants reproduce sexually, but can be forced to reproduce asexually.
The first lesson in the series, Plants 1: Plant Parents, discusses sexual reproduction in plants, while this one discusses asexual reproduction. Asexual reproduction in plants is referred to as vegetative propagation. In this lesson, students will do a project in which they choose a plant and try to propagate it. The project will take about 6 to 8 weeks to complete. During this time, students will research propagation, attempt to propagate a plant, keep a journal, and write a summary when the project is finished.
This project will be done individually by the students. It will require some time in the library and access to the Internet to research vegetative propagation and the specific plant that they hope to propagate. It is recommended that the students have at least two class periods (45 minutes each) in the library to complete this research. Once the research is complete, students will attempt the propagation at home. They must write and follow directions for the propagation, and keep a journal that tracks the progress of the plant for approximately six weeks.
Ideas in this lesson are strongly related to those found in the 5F Evolution of Life benchmarks. Especially relevant is the notion that individual organisms with certain traits are more likely than others to survive and have offspring, and that changes in environmental conditions can affect the survival of individual organisms and entire species. These ideas are useful in understanding some of the beneficial applications of vegetative propagation. This lesson can also be used to reinforce ideas in 5B Heredity, demonstrating in a concrete way the ways in which plants can reproduce asexually.
Prior to doing this lesson, students should have an understanding of both sexual and asexual reproduction and how genetic information is passed from parent to offspring in both cases. It is also important for the students to be familiar with the parts of the flower and their roles in sexual reproduction, which are concepts presented in the first lesson of this series.
Also, students will need the Plant Propagation Project Packet. This packet can be used as is, or as an example to create a packet that would suit the needs of your particular students.
This packet includes:
- Title page
- Student guidelines
- Plant journal pages
- Letter to parent (It is recommended that parents be notified by letter so they are aware of the requirements of the project. Emphasize to the parents that the grade for the assignment depends on the research, effort, journal, and writing assignment, not on keeping the plant alive and propagating it successfully. The letter should also ask parents/guardians to assist with knowledge and materials, but not to do the project for their children.)
In addition, it would be helpful to have reference books on plant reproduction available for use during class discussions. Gardening books may also be useful to students as they try to propagate their own new plants.
Review the concepts presented in the first lesson of this series, Plants 1: Plant Parents. Be sure that the students are familiar with sexual reproduction in plants, including the parts of a flower and their roles in sexual reproduction.
Ask students questions such as:
- Have you ever started a new plant from seeds? Describe what happens.
- Do all new plants start from seeds?
- Where do seeds come from?
- Do you know of any other ways to start new plants? Have you ever tried these?
Students could use reference books you have made available to find the answers to these questions, or expand on what they already know.
Explain to students that most plants propagate through sexual reproduction; but not all plants, and not all of the time. Some plants reproduce by asexual means. Emphasize that in asexual reproduction, all of the genetic information comes from only one parent. Many plants reproduce this way naturally.
Say to students: In this project you will be finding out about vegetative propagation in plants. Whenever plants reproduce asexually by any means, either naturally or artificially, the term vegetative propagation is used. It means that vegetative plant tissues (or parts of the plant that are not used in sexual reproduction) are used to produce new plants.
An introduction to various methods of propagating can be found in Flower Power: Kerin Lilleeng-Rosenberger. The body of the article is an interview with a nursery manager and gardener at the National Tropical Botanical Garden who has been instrumental in the quest to rescue Hawaii's growing list of endangered native plants.
Students can read this article and then discuss the following questions:
- What plant propagation techniques does Kerin Lilleeng-Rosenberger use to try to preserve native plants?
- What are some of the obstacles she faces?
- What does she mean when she talks about using both seeds and cuttings to preserve plants?
Refer students to the following two resources from the Plant Physiology at Eastern Connecticut State University website. These articles can be used to help introduce the lesson and as reference materials during the course of the six-week project for further understanding of vegetative propagation:
Distribute the Plant Propagation Project Packet and explain the project to students, answering any questions they have. Emphasize to students that they should select plants that they have access to and would be interested in propagating. Depending on the time of year, indoor houseplants may be more successful. During the winter in colder climates, outdoor plants are dormant, and will not propagate.
Once parents are informed and students have selected plants, students should be given ample time in the library to do the research. The journal includes pages for plant characteristics, but remember the suggested information listed in the journal is by no means an exhaustive list of information that the students could or should include.
The student packet also includes the following list of suggested Internet resources for students:
- Natural Vegetative Propagation
- Artificial Vegetative Propagation
- Vegetative Propagation of Houseplants
- Plant propagation leaflets
Check student journals to be sure that they have enough information about their plants and about vegetative propagation. Student journals should include step-by-step procedures for doing the propagation.
Within one week of completing the research, students should have finished the propagation and recorded their first observations in their journals. Stress that the journals should be as descriptive and precise as possible. The observations should not read, "The plant turned brown."; but rather, "A one centimeter circular brown spot appeared on the center of the leaf." An entry for what was done to the plant should not be, "I watered it."; rather, "The plant was given 50 ml of water."
Students should care for the plants according to the information they find in their research. They need to be sure that the plant is getting the proper amount of light and water, and the proper type of soil. The plants should be monitored and observations (including drawing or photographs) recorded at least twice a week. (Check the journals each week to be sure that the students are keeping adequate records and checking on the plant at least twice a week.)
If a plant dies early in the project, have them attempt it again. They must note in the journal that the plant has died, and a new attempt is being made. If a plant dies later in the project, it will be up to your discretion to decide if the student will have enough time to attempt a second propagation.
At the end of six weeks, the students should know if the propagation was successful. It is time for them to write a summary and evaluation of the project as described in the journal.
Students should bring their plants into class, dead or alive. Students often want to share their successes and failures. Again, the assessment of the project should not be based on whether or not the plant survived; it should be based on the research notes, journal, and written paper.
A suggested rubric is provided with this lesson, however, you should adjust this rubric to reflect the aspects of the project that are most appropriate for your classes. There are several resources on the Internet that describe the use of rubrics in the K-12 classroom, a few of which are highlighted here.
To learn more about rubrics in general, see Make Room for Rubrics on the Scholastic site.
For specific examples of rubrics, more information, and links to other resources, check out the following sites:
- Kathy Schrock’s Guide to Everything: Assessment and Rubrics
- Assessment: Creating Rubrics
- Rubrics for Web Lessons
Finally, you can go to Teacher Rubric Makers on the Teach-nology.com website to create your own rubrics. At this site you can fill out forms to create rubrics suitable for your particular students, and then print them instantly from your computer.
Arrange a field trip to your local garden center or nursery. They can show you how plants are propagated commercially in their greenhouse.
A classroom garden is also a great way to foster interest in plants. There are a lot of resources on-line that help with classroom gardens. Check out Kidsgardening for ideas.
The Vegetative Propagation Project is an excellent model for an alternate way to conduct this lesson. Originally found at the Activities Exchange located on the now defunct Access Excellence website, the project can still be found at the Internet Archive.