Plants Can’t Swim
Lesson Overview
Goals
- Describe why proper drainage is important
- Identify specific negative effects on plant development
Outcomes
Teaching Primer
Plants love water. In fact, they can’t live without it.
But like the famous quote from Mark Twain states “Too much of anything is bad…” Of course, the second half of that quote is “but too much good whiskey is barely enough.”
Though there is little evidence of the impact of whiskey on plants, it is well documented that too much water has dramatic and costly effects on plant development.
Gardeners and farmers must walk that fine line between too much and not enough. But there are techniques that can be applied to watering that when combined with a properly designed drainage system will produce that balance with little effort.
Like many other aspects of growing edible plants, knowing when to water, how much to water, and how to properly assess the situation comes easier with time and experience. Knowing the consequences of over watering or poor drainage will make any gardener cringe at the possibilities.
Teach the Teacher
Tools & Materials
- 8 Solo Cups or recycled plastic containers
- Water
- Knife
- 4 stopwatches
- Soil
- Notepad and pencil to record results
Vocabulary
- Root rot
- Stunted
- Leaching
Method
Introduction (10 minutes)
Begin the lesson with an overview of the importance of drainage and then highlight the various effects that poor drainage has on plant development.
Activity (20 minutes)
Prepare an experiment using four plastic containers – Solo Cups or recycled yogurt containers work well – each with a different composition of soil. Punch a series of small holes in the bottom of each container to allow the water to drain through. Fill each container halfway with soil. One should have loose soil from the raised planters, one with the same soil but compacted by hand, one with a heavier clay soil, and one with a loose sandy soil. Pair each container of soil with a second cup of water so that each pair has the same level of soil and an equal amount of water.
Select four Students to be pourers and four to be timers. Pair a timer with each pourer and have all four pourers begin pouring their water into their soil at the same time. The timers will record the time from the start until water begins to drain out the bottom of the soil container and then also until all of the water has drained.
Discussion (10 minutes)
Which soil composition drained the quickest? Why do you think that is? The water draining out was no longer clear. What do you think was in the water? How will that affect the plants over time?
Assessment (5 minutes)
Use the following questions to assess the Students before and after the lesson. Tally the responses of the group in the Assessment Tracking Log for comparison:
- By a show of hands, how many of you can explain the importance of proper drainage?
- Now that you know why it’s important for plants to have proper drainage, how many of you think you could tell if the raised planters are draining properly?
Related Lessons
Give the Intermediate or Advanced lessons a try now that you’ve completed the Beginner Lesson!
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