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Science Project: How Does Salt Affect Seed Germination?

VirginiaLynne is an educator and mom of 5. Her science fair articles are from projects that competed successfully (local, state, national).

The amount of salt in soil is a major problem for growers.

The amount of salt in soil is a major problem for growers.

Excellent for Junior or Senior High

This is the research plan my daughter used for her junior high project. She won first place at our regional contest and competed at state. She also won some special awards because she tackled a real-world problem.

The reason this simple project did so well is that she was able to explain how important it is for farmers to be able to determine when the salt concentration in soil hurts the germination of plants.

Another child in our family did a variation of this project in 5th grade for her school project, so I know that this experiment also works with younger children, but be sure that your child has at least one to two weeks time for the experimental process.

Experimental Question

The question is what you are going to test. You can do this same experiment in many different ways and create an entirely different experiment by changing one or more of the following:

  • The amount of salt in water.
  • The number of seeds you use.
  • The type of seeds you use.
  • How you grow the seeds.
  • Where you put the seeds to grow them.
  • What you use to grow the seeds on.

Sample question: How do different concentrations of salt in water affect the germination of radish seeds? If 100 radish seeds are put in coffee filters in Ziplock bags, and then the filters are saturated with water that has had different amounts of salt added to it, how does the germination rate change, and at what amount of salt do the seeds stop germinating?


Your hypothesis is your guess about what your experiment results will be. After doing your experiment, you will compare your hypothesis with the data from your experiment. That comparison will be your conclusion.

Sample hypothesis: The more salt added to the water, the fewer seeds will germinate. The radish seeds will not germinate at all in a solution with more than 3 teaspoons of salt in 8 oz. of water.

When soil has too much salt, crops won't grow well.  This experiment studies how salt affects seed germination.

When soil has too much salt, crops won't grow well. This experiment studies how salt affects seed germination.


  1. 10 Ziplock Bags
  2. 1000 radish seeds
  3. 10 coffee filters
  4. tap water (tap water is the control)
  5. distilled water
  6. table salt
  7. measuring spoons
  8. 10 cups
  9. 8 oz. measuring cup
  10. Science journal and pen (or computer document)
Radish Seeds in Salt Water

Radish Seeds in Salt Water

Radish Seeds Germinating in Bag

Radish Seeds Germinating in Bag


Take ten separate cups. Label them A through J. Fill them as follows:

  1. Solution A: 8 oz. tap water
  2. Solution B: 8 oz. distilled water
  3. Solution C: 8 oz. distilled water with ½ teaspoon of table salt. Stir to dissolve the salt.
  4. Solution D: 8 oz. distilled water with 1 teaspoon of table salt. Stir to dissolve the salt.
  5. Solution E. 8 oz. distilled water with 1 ½ teaspoons of table salt. Stir to dissolve the salt.
  6. Solution F. 8 oz. distilled water with 2 teaspoons of table salt. Stir to dissolve.
  7. Solution G. 8 oz. distilled water with 2 ½ teaspoons of table salt. Stir to dissolve.
  8. Solution H. 8 oz. distilled water with 3 teaspoons of table salt. Stir to dissolve.
  9. Solution I: 8 oz. distilled water with 3 ½ teaspoons of table salt. Stir to dissolve.
  10. Solution J: 8 oz. distilled water with 4 teaspoons of table salt. Stir to dissolve.

2. Place the 10 Ziplock Bags down on the counter at room temperature. Label the top and bottom of each bag with the letter of the solution to be used in each one (A through J).

3. Unzip the bags and put a coffee filter in each one.

4. Pour one tablespoon of solution on the filter in the bag with the same label, making sure it soaks the whole coffee filter.

5. Divide the 1000 seeds into groups of 100. Put 100 seeds on the filter of each Bag. Make sure the seeds are scattered evenly over the filter.

6. Zip up the Bags. Place all 10 bags at room temperature out of direct sunlight (seeds don't need light to germinate and light can cause fungus to grow).

7. Observe the bags daily and record the number of seeds that have germinated in each and any other changes in the seeds.

8. Record results in your science journal.


In truth, this experiment doesn't really require any particular safety procedures. However, if you are required to include this section in your project notes, you can write something like the following:

Sample Safety Procedures: You need goggles so the salt water doesn't splash in your eyes and gloves so you do not transfer bacteria to the seeds.

Farmers sometimes flood their fields to leech out the salt that accumulates in the soil through water evaporation. That takes a lot of water and contributes to droughts.

Farmers sometimes flood their fields to leech out the salt that accumulates in the soil through water evaporation. That takes a lot of water and contributes to droughts.


As you conduct your experiment, you should record what happens every day on a chart. When your experiment is finished, you will look at the results and write out what happened. You can choose to talk about this in different ways:

  • Describe what happened day by day to each bag.
  • Describe the overall results and then talk about particularly interesting things that happened.
  • Talk about the results for each bag and then compare them.

Sample Table for Results

Solutions:A: number sproutedB: number sproutedC: number sproutedD: number sprouted

Day 1


Day 2



Day 3



Day 4


What do you think about your results? In your conclusion, you explain:

  1. Whether your guess was right or not.
  2. How your results compare to your hypothesis.
  3. Your ideas of why your results came out the way they did.
  4. How you would revise the experiment to make it better.
  5. What experiment would you do next to get more information?
  6. The importance of your experiment to real-world problems.


An abstract is a short summary of everything in your experiment. It explains your procedures, your results, and your conclusion briefly. Scientists rely heavily on abstracts when they are researching. They will read the abstract to get an overview of that experiment and decide if they need to read the full article.

Sample Abstract of Experiment and Results: The problem was to determine the effect of salt water on germinating radish seeds and also to determine if there was a maximum concentration that could be tolerated.

To do this, coffee filters were wet with 1 tablespoon of salt water from cups that increased in concentration by 1/2 teaspoon of salt in each cup of 8 oz. of water. The filters were then placed in the plastic bags. The 50 seeds were then placed on top of the coffee filters inside the bag. The seeds that germinated were counted and charted. Tap and distilled water without salt were used as controls.

The results were that the germination was 100% with the controls, tap and distilled water. In the groups exposed to salt water, the germination decreased as the salt concentration increased, and no germination occurred at amounts of 1.5 tsp. of salt or higher. This supported the hypothesis, which was, "The more salt in the water, the fewer seeds will germinate."

This information could help gardeners and farmers to know when saline reaches dangerous levels for radish seeds.

Experiment Tips

  • Start early: It is always a good idea to start your experiment early so that you have time to re-do it if you have any problems. Two of my children did versions of this experiment for our state science fair. Maggie, who did the experiment first, found that none of her seeds germinated! Luckily, she had started her experiment early enough that she had to time revise her procedures, adding less salt in the water, and re-do her experiment.
  • Tell the whole story: In her conclusion and results, Maggie wrote the whole story of her experiment, the original failure, and her second try, which is exactly what my husband does when his experiments don't work the first time!
  • Be honest: Scientists are always honest about their results. If your experiment doesn't work out but you did everything you said you would do, and you don't have time to revise and do it again, you should still publish your results exactly. What you can put in your conclusion is how you would alter the experiment next time.


  • Plants not seeds: You can do a variation on this project by watering plants with water with different concentrations of salt to see how salt water affects the growth of plants. As the coordinator of an elementary science fair, I've seen students do lots of plant watering experiments using different kinds of water, or liquids other than water. but I've never seen a salt experiment.
  • Different types of seeds: Radish seeds sprout quickly, but many other types of crop seeds could work as well.
  • Plant the seeds: You could do a longer variation of this project by planting some of the seeds that sprout and continuing to water them with the same salt concentration.

Questions & Answers

Question: What are the variables?

Answer: The concentration of saltwater is the variable.

Question: How could we find out how much salt mung beans can tolerate?

Answer: Do the same experiment but use mung beans.

Question: Do you need a lot of seeds to see how salt affects seed germination? Is it okay to use about four seeds in each Ziploc bag?

Answer: I would not recommend using only a few seeds for each bag because you will not have enough data for your results. These are very inexpensive seeds. I'm sure we got them for under a dollar. I would suggest using at least fifty per bag.

Question: How does salt affect the growth of a radish seed?

Answer: That is a good title for this project. Your experiments will give you the results. Here are the types of things that farmers would be concerned about:

1. Does the seed germinate less quickly?

2. Does mold develop on the seed?

3. Do fewer seeds germinate?

4. Does the sprout die after germination?

5. Does the sprout look stunted?

Question: How often you water the seeds, if at all?

Answer: Check each bag every day to make sure that the paper towel or coffee filter is moist but not wet. If you see a lot of water in the bag, it is probably too much water. If you see there is some dryness, then add just enough water (of the appropriate salt concentration) to make it moist again. Each bag will be a little bit different because the number of germinating seeds will change the amount of water needed. Since you need to check the bags daily to count the seeds that have germinated, it is easy to also check each bag to see if it needs more water. Keep your water concentrations in covered containers so that you don't need to make any more of them. The containers need to be covered so that they don't evaporate and cause the salt concentrations to increase.

Question: Will mung beans work in this seed germination experiment?

Answer: I have not done this experiment with mung beans, but I have grown them. They should work in the experiment, but because they are not generally grown in the ground, the importance of salt concentration is not quite as relevant. If you want to test this project with an emphasis on agriculture, you should probably choose a seed crop that is grown by farmers in the ground.

Question: Why don’t Mung beans grow with salt water?

Answer: This project could be done with all kinds of seeds that sprout easily on wet paper towels or coffee filter paper. Mung beans, which are used as "bean sprouts" when they have sprouted would be a good substitute in this experiment.

Question: What is the link between lack of germination and plant death?

Answer: If the seeds don't germinate, then they can't produce a full-grown plant. Another way to do this experiment is to water full-grown plants with different concentrations of saline water.

Question: If the seeds need to be watered, do we have to water with their relative solution? Like if the solution C for Zip Lock bag C is water with 1.5 teaspoons of salt in it, do we have to use that for watering them daily?

Answer: Yes. If you need to add water to the bag, you need to use the same solution to ensure that the experiment is the same. You might want to save the solution you make in a sealed container (so it does not evaporate and change the salt concentration) in case you need to do this. However, if you have the bag closed tightly, you will probably not need to add more solution.


John on April 18, 2019:

I conducted this experiment.

Now I need to start my Lab report. For my introduction, I need to include background research. Do you have any suggestions on what I can put so that it is good for people who are reading it who have no understanding of biology at all?

Virginia Kearney (author) from United States on April 02, 2019:

Hi Faizhan--You probably used too high of a salt concentration. We did that one time too, and none of them grew. Try reducing the salt concentrations by at least half.

Faizhan on April 02, 2019:

For some reason, my control fully grew within 4 days except the ones with salt and 1 of them disappeared. I did 4 trials or 4 levels : .5 tsp, 1 tsp, 1.5 tsp, and 2.

Please help me out and tell me what I should do I still have a week and 2-3 days left to conduct this experiment.

Virginia Kearney (author) from United States on March 28, 2019:

I am not sure you can complete the whole project in less than two weeks. If you do try, you should probably take them home on the weekend so you can have more days of observation.

Faizhan on March 27, 2019:

OK, thanks for your reply.

I have till April 11th to complete this so do you think it's possible that I could finish this by April 4th? And I'm also planning to do it at my school with a partner. And since I'm working with a partner I would need to do 10 trials, and have 4 Independent variables too. So please advice if you could.

Virginia Kearney (author) from United States on March 27, 2019:

Hi Faizhan, you can either do salt and amount of sunlight, with or without putting them in a plastic bag, or use soil/plastic bag.

Faizhan on March 27, 2019:

I need to have 2 variables what suggestion could you give?

dynamite_bloom on March 04, 2019:

Why don’t Mung beans grow with salt water?

Nobs on September 22, 2018:

Good work

Virginia Kearney (author) from United States on September 12, 2018:

Hi Thomas, I have not tried lettuce seeds but I would assume this project would work with any type of seed that sprouts fairly quickly.

Thomas Scott on September 11, 2018:

Does it work with lettuce seeds?

Virginia Kearney (author) from United States on March 26, 2018:

Thanks for the comment Bob. I just answered a question about whether you could do this with mung bean seeds. I assume that this would work but I don't know how sensitive mung beans are to salt concentrations. The very first time we did this experiment, we found that we had put all of the salt concentrations too high. It may be that is your problem too. Go back and do salt concentrations that are half your original and that will probably work. You do that by putting half the amount of salt in the water, or by putting double the amount of water for each amount of salt.

Bob on March 26, 2018:

Trying doing this experiment with mung bean seeds, seeds with salt arnt growing, I closed the bag for first two days and then opened them, control grew but everything else didnt

Virginia Kearney (author) from United States on January 21, 2018:

Hi Kimi--If none of your seeds with any of the salt concentrations have germinated, you may need to try again using a solution which has less salt.

kimi on January 21, 2018:

my seeds which have salt in it has not germinated at all. is it wrong?

Virginia Kearney (author) from United States on January 09, 2018:

Hi Selena--The amount you put in the bag depends on the paper towel or filter you are using that absorbs the water and keeps the seeds moist but not wet. Too much moisture is going to cause problems with fungus or bacteria growth. Since different papers absorb differently, you will need to adjust the amount to fit your paper. We determined 1 TB worked best for our paper. This is how to do it: put your paper in the bag and add water one teaspoonful at a time. When the whole paper is wet, you have enough. A little extra is all right but you don't want lots of extra water.

Selena on January 09, 2018:

If you put about 20 seeds in each bag, would you recommend still adding 1 Tbsp of solution to each bag?

Virginia Kearney (author) from United States on January 08, 2018:

Hi Conny--we bought the seeds at our local seed store. These are ones used by farmers or home growers. Any seeds appropriate to your area would be fine, including ones that are available at Lowes, Home Depot or any garden store.

Conny on January 08, 2018:

what type of radish seeds did you use?

Virginia Kearney (author) from United States on September 04, 2017:

Hi Elle! You'll have to do the experiment to find out. You will write what happens each day in a table and then look at those results to write a narrative about your conclusion, which is how your results compared to the hypothesis.

Elle on September 03, 2017:

hi, i was just wondering what you would write in the results section of this experiment? thanks

Virginia Kearney (author) from United States on August 28, 2017:

Hi, Vaishali, Zip Lock bags are plastic bags that close at the top. You could use any container that can be closed so that the water doesn't dry out. Instead of coffee filters (which is thin but strong paper that you use to put coffee in and then drip water through it to brew the coffee), you could use any paper towel or napkin. Anything which would hold the water in but not soak the seeds too much. Too much water or just leaving the seeds in water could make them get a fungus.

Virginia Kearney (author) from United States on August 28, 2017:

Vaishali--Yes, that was our original plan, but our science fair coordinator did not want us to have two variables. I still think that would make a better experiment, however.

VAISHALI SANGANI on August 28, 2017:

What r ziplock bags , coffee filters then 8 oz. measuring cups....what r these...

Actually mam these materials r not available in India so plz mam can suggest some other materials so to perform my IP projects....for my practical exam

I am in 11 th std

Science student


VAISHALI SANGANI on August 28, 2017:

Can we use two specimens of plants... and daily putting both the solutions...

In first trying with concentrated and in second trying with distilled water or normal tap water which we use in our daily life....

Virginia Kearney (author) from United States on August 15, 2017:

Hi Farhiya! Actually, some people grow plants hydroponically, which means in water without soil. However, you do need to make sure they have all the nutrients they need. You might want to look up hydroponic plants. Actually, that would make an interesting experiment to see if you can get a plant to mature and grow fruit without soil.

Farhiya on August 15, 2017:

I was wondering if seeds need soil to grow or can it grow into a mature plant without soil.

Virginia Kearney (author) from United States on August 04, 2017:

Good question Lucy! You want to avoid letting them dry out and also avoid having them develop mold. Luckily, the salt tends to prevent the growth of fungus and mold. We generally kept them sealed shut but if you think you've gotten them too moist, you could leave a corner open to let them evaporate a bit.

lucy on August 04, 2017:

Just wondering if the ziplock bags need to be sealed shut, or should they be open for airflow?

Virginia Kearney (author) from United States on May 14, 2017:

Hi Vilda, you probably ought to allow at least 2 weeks for this project, although you might get enough results earlier, depending on how fast the seeds germinate.

Vilda on May 14, 2017:

Hi! This is a very interesting project. I am wondering how long time it took in total, from the seeding until finished.

Virginia Kearney (author) from United States on April 29, 2017:

Hi, Amber--Yes, oz. means fluid ounces.

Amber on April 29, 2017:

When you say oz. do you mean fluid ounces?

Virginia Kearney (author) from United States on April 17, 2017:

Hi Amber--that is a very good question. If the seeds are too wet, they can develop mold and that will mean you will have to start the project over again.

Amber on April 17, 2017:

Why should the seeds be kept damp and not wet?

Virginia Kearney (author) from United States on February 06, 2017:

Hi Brianna! This is an easy experiment to do that is actually about a very important problem that we need to solve. I hope you enjoy doing this and learn something about the environment and how we need to protect it.

Brianna Brown on February 06, 2017:

I was looking all over for a project like this one. I never new that I was going to find it I love it thank you!!!

Virginia Kearney (author) from United States on April 21, 2014:

Glad you like it Chelsea. One of my younger daughters just did a version of this one for her science fair project in 6th grade. It is easy but has a very important point. Right now in California they have a terrible drought. One of the problems with the fields in California is that they have a lot of salt in them. One of the ways they get rid of the salt is to flood the fields with water to let the salt leech out. Of course they can't do that when they don't get enough water. So finding out about how salt inhibits germination and growth is important.

chelsea on April 21, 2014:

I love this experiment

Virginia Kearney (author) from United States on April 09, 2014:

Aaliyah--I'm not sure what you mean by dependent and independent variables. The variable in this project is the amount of salt in the water. Everything else is constant. The plain tap water is the control.

Aaliyah on April 09, 2014:

Please tell me what are the dependent and independent variables

Virginia Kearney (author) from United States on November 20, 2013:

Ladruzzi--Check the filters daily. Only add water if they are getting dry. You want them damp and not wet. Two weeks is just about right.

landruzzi on November 20, 2013:

Sounds like a great experiment. My question is, do we dampen the filters on a daily basis or skip a day? I wasn't sure how long you would continue this project as well. Is it about a two week time frame of observing the seeds? Thank You.

Virginia Kearney (author) from United States on November 10, 2013:

Yash, If you are looking for an easy way to do it, you might want to have several bar graphs representing the progression of days with the numbers of germinated seeds indicated by different bars under the different salt concentrations.

Yash on November 10, 2013:

Can you help me make a rough graph of seed germinated vs. salt conc. ?

That on November 29, 2012:

Awesome I'm so doing this

Virginia Kearney (author) from United States on March 01, 2012:

Nova--thanks so much for telling me! I will pass this along to my daughter, she will be excited to hear about it. My son had his science fair at region yesterday and won first in his category--he gets to go on to state again now. I'm so glad that we have competitions which keep kids interested in science!

Nova on March 01, 2012:


My daughter did the experiment about salt n seeds ,she followed some of your ideas and she won first place in her science fair this yr in 2nd grd. Thank you so much, keep posting such inspiring experiments.good job.

Virginia Kearney (author) from United States on January 24, 2012:

Great! I'd love to have you come back and share how it worked for you. My daughter got 1st place in her regional for this project and also went to state.

learnlovelive from U.S. on January 18, 2012:

No problem, Virginia. I want to thank you for being so professional in your demonstration. The scientific method is so important, people don't even understand. And, "You Rock!" was both a pun and a double entendre. Your Hub was about salt, hence the rock pun and you posted a comment about the effects of music on plants. This is awesome, hence the part about you rocking...and you were actually talking about rocking out with the plants. That rocks, quite literally. Keep up the good work, your approach is well-appreciated and you are good at demonstrating thorough processes.

Virginia Kearney (author) from United States on January 18, 2012:

Thanks for stoping by learnlovelive! Hey keithlinpke--I've seen that one too! Or an experiment where people put some plants in a room with rock music, and other plants with classical. Interesting!

keithlipke from Fort Wayne, Indiana on January 17, 2012:

My science project was talking to plants :)

learnlovelive from U.S. on January 16, 2012:

Awesome. You rock.