Plant Root Systems

Taproot System:

The dandelion plant has a tap root system, which consists of a main root that grows straight down. This root is much larger than the roots branching from it. The smaller branching roots are called rootlets, and these roots grow laterally.

Plants with a tap root are difficult to transplant. When you pull on the plant, the shoot system often breaks away from the securely anchored taproot. This is why dandelions are hare to get rid of.

Taproots generally grow deeper into the soil than do fibrous roots.

Dicots generally have a tap root.

Fibrous Root Systems:

Grass has a fibrous root system, unlike a taproot, fibrous roots don’t really have a central root. If it is there it is not easily identified because all of the roots are about the same size. These roots branch out in all directions, forming a tangled mass that hides anything that might be called a main root.

Teaching Tips

Prepare examples of these two types of root systems.

1. Use the trowel or spade to dig up at least one  dandelion plant for each group of kids that will be observing them. Make sure that you get its entire taproot.

2. Wash the soil from the roots. You may have to soak the roots in a bucket of water to loosen the soil.

3. When the roots are relatively clean allow them to dry. To speed up the drying lay the plants on newspaper and/or blot the plants with paper towels.

4. Repeat steps 1 through 3 to collect and prepare grass roots. Again, make sure that you have all or as much of the root system as possible.

Examine and Compare Root Systems

Kids can use magnifying lenses to observe the two types of root systems.

46870: Janice VanCleave"s Plants: Mind-Boggling Experiments You Can Turn Into Science Fair Projects Janice VanCleave’s Plants: Mind-Boggling Experiments You Can Turn Into Science Fair Projects