Seed experiment #5: What liquids help seeds grow?

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After my kids and I sprouted seeds to see what the process entailed, we decided to carry out a series of seed experiments to learn more about seeds. Our seed experiments were designed to answer questions about what kinds of conditions seeds grow best in.

In previous posts I shared the results of our experiments that asked the questions:

In this fifth seed experiment, we have been addressing the question: “What liquids help seeds to grow?“

Note: For more seed activities your kids will love, see my Botany Unit Study page.

For the purposes of this experiment, we decided to test how seeds grow when given one of four different liquids:

plain water
salt water
sugar water
vinegar

For any experiment, it is important to set up conditions so that the only difference between the conditions is related to what you want to test. Because we wanted to test how seeds grow in a variety of liquids, it was important that all of the growing conditions for our seeds be the same EXCEPT for the liquid added to the dirt.

We started with four plastic cups, each filled about 1/3 full with dirt from our yard. To all cups we added three different seeds: a broccoli seed, a lettuce seed, and a pea seed. (The seeds were part of this set of heirloom seeds I purchased.)

Then we added labels that said “plain water,” “salt water,” “sugar water,” and “vinegar.”

To create our salt water, we added two teaspoons of salt to a cup of water.

And to create our sugar water we added two teaspoons of sugar to a cup of water.

Then to each of the seed cups we added the indicated liquid. We then placed the cups on our kitchen window sill to see how the seeds would grow. Over the next several days we continued to add liquid to each of the cups as needed to keep the dirt moist. I used the extra salt water and sugar water we created to continue watering the seeds in the salt water and sugar water conditions.

After one week, we noticed the following results:

Plain water: all three seeds had begun to sprout, with nice leaves already forming from the broccoli and lettuce seeds
Salt water: none of the seeds had begun to sprout
Sugar water: one of the seeds had just barely begun to sprout
Vinegar: none of the seeds had begun to sprout, although a strange, off-white colored substance had formed on the surface of the dirt

So after conducting this experiment, how would we answer our question “What liquids help seeds grow?”

The results of our experiment indicate that plain water is the best growing liquid for seeds. However, seeds may also grow in sugar water. Per our expectations, the seeds failed to sprout in either the salt water or the vinegar. Apparently mother nature, with her plain water, does know best when it comes to providing for seeds!