Step 1
Planning
Order Seeds
Place an order through the website to receive seeds. You will need to log into your Let's Talk Science account before ordering. If you do not have an account, you can create one from the login page.
If you are participating with more than 10 classes, please contact tomatosphere@letstalkscience.ca directly to make special arrangements with the coordinator.
Familiarize yourself with the Tomatosphere™ resources
Read through this guide (Seed Investigation) fully then explore our supporting resources. The learning resources below provide guidance on how to introduce the activity and extend the learning beyond the Investigation. They offer suggestions on how to develop inquiry skills and cross-curricular concepts. They include lessons to extend the investigation and articles with background information on related topics. You can search the resources by curriculum or keyword, or find resources based on topic such as plants and space.
Plan time to do the Investigation
Once you have chosen some resources to use with your students, you can move onto planning time to do your investigation.
If you are in a classroom setting, plan to plant the seeds on a Wednesday or Thursday. It usually takes 5-7 days for the first seeds to germinate. By planting them on those days, the first signs of germination should occur on a school day when the students are present, and not over the weekend.
Do not plant the seeds prior to a school break, such as the traditional spring break or religious holidays, when you might not have the opportunity to water the plants properly, or when the temperature in the school may be lowered (which may affect growth).
The table below should help you plan the investigation.
| Task or Event | Estimated Timing |
|---|---|
| Seed planting | 40-60 minutes, depending on the age of students |
| Observing, measuring and recording | 5-10 minutes per day, every day preferably at the same time |
| Germination | 5 to 7 days in ideal conditions, but can take up to 3 to 4 weeks |
| Submit and review results and learn the identity of the space seeds | 5-10 minutes through the Tomatosphere website, more if submitting results with students. |
Step 2
Prepare
Supplies
Tomatosphere™ will provide you with two packs of seeds per class, each marked with a different letter. One package contains the "control" seeds (untreated) and the other package contains the “experimental” seeds (treated), which have been flown to space or have experienced space-like conditions. You will not know which pack is which until after you submit your results in order to maintain a blind test.
You will need to source the following planting materials per participating class or group:
You can use any growing medium such as potting soil, peat pellets, seedling plugs, or rockwool cubes (if using a hydroponics system). These can be purchased online or at a local garden or dollar store.
Did you know? Peat pellets are the easiest and tidiest solution for planting with young students. However, they are bound in a plastic mesh that does not decompose in the garden.
Containers can be any small container such as empty yogurt or pudding cups, egg cartons, fiber pots or origami paper pots. Ideally, containers should be about 7.5 cm (3”) deep to allow for roots to grow.
If you plan to use a repurposed plastic container, make sure to make drainage holes in the bottom. These also need to be very clean to avoid disease and should be washed by a teacher before use.
Seeds need water, oxygen and warmth to start growing so make sure you put your seeds somewhere warm! A drafty windowsill is not be the best place to germinate your seeds.
You can find these reproducibles on the Teaching Suggestions by Grade pages.
Step 3
Start the Investigation
Introduce the project
How you introduce Tomatosphere™ is up to you. The Introductory Learning Activity Suggestions in each of the Teaching Suggestions by Grade has age-appropriate suggestions and scenarios that can be used to initiate and engage students in the Seed Investigation.
Plant the seeds
- If using peat pellets, soak them in lukewarm water until fully expanded (about 4 cm tall). This can take an hour or more depending on how fresh the pellets are. It is best to do this before planting with a group of students.
- If using soil, place some soil into each container or seedling tray with cells. Do not fill the containers to the top, leave a little room for water. If using another planting medium, follow the instructions that come with it.
- Place your pots or peat pellets into a tray to catch any excess water. Label the planting containers and/or the trays accurately with the letter on the seed package. You should have two groups of pots/pellets, one for each seed pack.
Reminder
Ensure your labelling is accurate so that the seeds do not get mixed up. This is very important for accuracy of the final results.
- Individually, have each student press one seed into each pot or pellet to a depth that is about the same as the length of the seed (2-3 mm). Do not plant the seeds too deep in the soil as they will not be able to emerge.
- You do not have to plant all the seeds in the pack if you do not want to. There will likely be a different number of seeds in each seed pack. It is fine to plant more of one group of seeds than the other as long as you record how many seeds you have planted for both groups.
Reminder
Make sure to record how many seeds you have planted for each group. You will need this information to submit your results later.
Step 4
Seed Care
Watering
The growing medium should be kept moist during the germination phase. Check the seeds daily to ensure the soil is damp to the touch, but not soaking wet. Add water accordingly as needed. The watering schedule may vary depending on the humidity of the room.
Remember to water the peat pellets or soil before leaving for the weekend and as soon as possible upon return. It is important that the peat pellets or soil does not dry out.
Fair Test Alert
To ensure a fair test is conducted, make sure both groups of seeds are exposed to the same conditions (i.e., heat and water).
Germination and Growing Conditions
You will need a place in your classroom/learning environment that provides the best conditions possible for your seeds. Click on the topic below for more detailed information.
Seeds need a warm environment to germinate. Tomato seeds will not germinate below 10°C. Their ideal temperature range for germination is between 16-30°C.
If you are planting your tomato seeds while it is cold outside, do not leave your planted seeds in a window, especially at night. Seeds do not need light to germinate, but they do need a warm environment. Keeping them away from drafty windows will increase your germination rates.
Tip: If your seeds are not germinating, they might not be warm enough. Keep them away from drafts and place a lamp with an incandescent light bulb (or other gentle heat source, such as a seedling mat) near them to help keep them warm. (Picture of goose neck lamp).
Warmth
Seeds need a warm environment to germinate. Tomato seeds will not germinate below 10°C. Their ideal temperature range for germination is between 16-30°C.
If you are planting your tomato seeds while it is cold outside, do not leave your planted seeds in a window, especially at night. Seeds do not need light to germinate, but they do need a warm environment. Keeping them away from drafty windows will increase your germination rates.
Tip: If your seeds are not germinating, they might not be warm enough. Keep them away from drafts and place a lamp with an incandescent light bulb (or other gentle heat source, such as a seedling mat) near them to help keep them warm. (Picture of goose neck lamp).
As well as warmth, seeds need a damp environment to germinate. Make sure you are watering your seeds consistently and do not let them dry out. The soil should be kept moist, but they should not be sitting in water for extended periods of time, as they could start to rot. Monitor younger students if they are watering the plants. If your seeds do get too much water, remove the extra water from the bottom of the tray as needed.
Tip: For seeds that have not sprouted yet, you can leave the seedling dome of the tray on over the weekend. This will help keep them warm and will keep the water from evaporating too quickly from the growing medium over the weekend, especially if your learning environment is dry.
Tip: It is Ok to leave a little water in the bottom of the tray over the weekend once the seeds have sprouted. This will help keep them damp until they can be watered again.
When watering your plants, it is better to use room temperature or slightly warm water. Do not use very cold or very hot water.
Water
As well as warmth, seeds need a damp environment to germinate. Make sure you are watering your seeds consistently and do not let them dry out. The soil should be kept moist, but they should not be sitting in water for extended periods of time, as they could start to rot. Monitor younger students if they are watering the plants. If your seeds do get too much water, remove the extra water from the bottom of the tray as needed.
Tip: For seeds that have not sprouted yet, you can leave the seedling dome of the tray on over the weekend. This will help keep them warm and will keep the water from evaporating too quickly from the growing medium over the weekend, especially if your learning environment is dry.
Tip: It is Ok to leave a little water in the bottom of the tray over the weekend once the seeds have sprouted. This will help keep them damp until they can be watered again.
When watering your plants, it is better to use room temperature or slightly warm water. Do not use very cold or very hot water.
Seeds do not need light to germinate. Once seeds have germinated and leaves have appeared, place your seedlings in a window that gets a lot of light or put them under a grow lamp. Tomato plants need a lot of light to grow properly and produce fruit. If you are planning to use your plants to further the investigation or want them to eventually bear fruit, make sure they get at least 8 hours of full light in a window or under a grow lamp. Make sure to move them away from the window if it is cold outside at night.
Light
Seeds do not need light to germinate. Once seeds have germinated and leaves have appeared, place your seedlings in a window that gets a lot of light or put them under a grow lamp. Tomato plants need a lot of light to grow properly and produce fruit. If you are planning to use your plants to further the investigation or want them to eventually bear fruit, make sure they get at least 8 hours of full light in a window or under a grow lamp. Make sure to move them away from the window if it is cold outside at night.
Seeds need a warm environment to germinate. Tomato seeds will not germinate below 10°C. Their ideal temperature range for germination is between 16-30°C.
If you are planting your tomato seeds while it is cold outside, do not leave your planted seeds in a window, especially at night. Seeds do not need light to germinate, but they do need a warm environment. Keeping them away from drafty windows will increase your germination rates.
Tip: If your seeds are not germinating, they might not be warm enough. Keep them away from drafts and place a lamp with an incandescent light bulb (or other gentle heat source, such as a seedling mat) near them to help keep them warm. (Picture of goose neck lamp).
Warmth
Seeds need a warm environment to germinate. Tomato seeds will not germinate below 10°C. Their ideal temperature range for germination is between 16-30°C.
If you are planting your tomato seeds while it is cold outside, do not leave your planted seeds in a window, especially at night. Seeds do not need light to germinate, but they do need a warm environment. Keeping them away from drafty windows will increase your germination rates.
Tip: If your seeds are not germinating, they might not be warm enough. Keep them away from drafts and place a lamp with an incandescent light bulb (or other gentle heat source, such as a seedling mat) near them to help keep them warm. (Picture of goose neck lamp).
As well as warmth, seeds need a damp environment to germinate. Make sure you are watering your seeds consistently and do not let them dry out. The soil should be kept moist, but they should not be sitting in water for extended periods of time, as they could start to rot. Monitor younger students if they are watering the plants. If your seeds do get too much water, remove the extra water from the bottom of the tray as needed.
Tip: For seeds that have not sprouted yet, you can leave the seedling dome of the tray on over the weekend. This will help keep them warm and will keep the water from evaporating too quickly from the growing medium over the weekend, especially if your learning environment is dry.
Tip: It is Ok to leave a little water in the bottom of the tray over the weekend once the seeds have sprouted. This will help keep them damp until they can be watered again.
When watering your plants, it is better to use room temperature or slightly warm water. Do not use very cold or very hot water.
Water
As well as warmth, seeds need a damp environment to germinate. Make sure you are watering your seeds consistently and do not let them dry out. The soil should be kept moist, but they should not be sitting in water for extended periods of time, as they could start to rot. Monitor younger students if they are watering the plants. If your seeds do get too much water, remove the extra water from the bottom of the tray as needed.
Tip: For seeds that have not sprouted yet, you can leave the seedling dome of the tray on over the weekend. This will help keep them warm and will keep the water from evaporating too quickly from the growing medium over the weekend, especially if your learning environment is dry.
Tip: It is Ok to leave a little water in the bottom of the tray over the weekend once the seeds have sprouted. This will help keep them damp until they can be watered again.
When watering your plants, it is better to use room temperature or slightly warm water. Do not use very cold or very hot water.
Seeds do not need light to germinate. Once seeds have germinated and leaves have appeared, place your seedlings in a window that gets a lot of light or put them under a grow lamp. Tomato plants need a lot of light to grow properly and produce fruit. If you are planning to use your plants to further the investigation or want them to eventually bear fruit, make sure they get at least 8 hours of full light in a window or under a grow lamp. Make sure to move them away from the window if it is cold outside at night.
Light
Seeds do not need light to germinate. Once seeds have germinated and leaves have appeared, place your seedlings in a window that gets a lot of light or put them under a grow lamp. Tomato plants need a lot of light to grow properly and produce fruit. If you are planning to use your plants to further the investigation or want them to eventually bear fruit, make sure they get at least 8 hours of full light in a window or under a grow lamp. Make sure to move them away from the window if it is cold outside at night.
Step 5
Observe and Record
Observe
The primary objective of the Seed Investigation is to determine the number of seeds that germinate compared to the number planted for each of the two types of seeds (treated and untreated).
A seed can be considered to have successfully germinated when two (2) distinctly separate embryonic leaves (cotyledons) can be seen.
Record
Record how many seeds germinated each day for 2-3 weeks or until 5 days after the last seed germinates. Use a marker such as a stir stick or toothpick, to mark once each seed has been recorded. See the chart below.
| Group A | Group B | |
|---|---|---|
| Number of seeds planted | 29 | 31 |
| Date of planting seeds | April 9 | April 9 |
| Date on which first seed germinated | April 18 | April 19 |
| Date on which last seed germinated do not count seeds that did not germinate |
April 30 | May 4 |
| Total Number of seeds that germinated | 28 | 29 |
Step 6
Reveal the Identity of the Space Seed
In order to learn the identity of the space seeds, you must submit your results. All results are valuable, even if your seeds did not germinate!
Submit your Results
To submit your results, you will need the following information:
Your Let's Talk Science account username and password
How many seeds of each group you planted
How many of each group germinated
Review the results
Once you have submitted your results, you will learn the identity of the space seed, the national germination average for each group and more information about the journey of the space seeds.
Celebrate your Contribution
After you have submitted your results you will receive a Certificate of Participation that you can print off for each of your students. The certificate is signed by former Canadian Space Agency astronaut, Dr. Robert Thirsk, and the principal investigator for the Tomatosphere™ project, Dr. Michael Dixon, University of Guelph.
Share your experience
Share pictures of your experience with us on X @LetsTalkScience or through email at tomatosphere@letstalkscience.ca. You can also share your feedback about the project with us by filling out the project survey.
Planning for Next Year
Remember to order seeds every year. You can join our mailing list to receive reminders to order your seeds.