FDA VIII Students Learn About Different Soil Mediums


Students at Frederick Douglass Academy (FDA) VIII are learning all about the various methods used to grow plants. Garden Educator Jacqui Roytman started her winter program introducing students to hydroponics, using water instead of soil to germinate seeds. After a few lessons, the middle-schoolers have learned that hydroponics uses different mediums to cultivate vegetation, such as Hydroton clay balls, Rockwool cubes and Peat Pods.

Over the course of the winter, Roytman has explored a multitude of ways to germinate seeds indoors with the students, so that these plants can be transplanted into the Spring Creek Recreational Fund’s (SCRF) Urban Garden Classroom (UGC) in the spring. Their last class featured sunflower seeds being planted inside of a medium called Peat Pods, which is made from sphagnum peat (a type of moss) and a special fertilizer all enclosed in a small net. These tiny disk-like pods expand when soaked in water for several minutes, and they make the perfect tool for seed starting. Since it takes several weeks for the sunflowers to germinate into seedlings, Roytman showed the students how to make their own soil.

One of the many components in preparing for spring gardening is not just germinating seeds, but creating compost and soil for the garden beds. Every few years the soil needs to be replaced within the garden beds because it tends to disintegrate overtime and loses key nutrients. Roytman explained to the class that they can make their own potting soil by adding perlite or vermiculite and either peat moss or coir.

Roytman told the class that perlite is an expanded volcanic rock that is made up of light material, which holds more air and provides excellent drainage. Vermiculite is another option to use instead of perlite. Some people prefer vermiculite because it holds in water, nutrients and air, while perlite can only hold in more air. Adding peat moss to the mixture gives the soil a course texture, providing both aeration and the ability to hold water so that the soil does not dry out quickly. Coir could also be used instead of peat moss and is a natural fiber extracted from coco-nut husks. Coir is rot resistant, has excellent aeration and retains moisture.

The students took turns examining the different mediums to create a potting mixture, and then they helped combine the materials together. Roytman compared mixing the potting soil to baking a cake. Each ingredient must be measured carefully because too much of one thing could cause the soil to dry out or retain too much water. In addition, the students learned that the seaweed, kelp, makes for an excellent fertilizer, providing plants with a lot of nutrients.

Next week, Roytman will be teaching her classes how to build their own hydroponic units using recyclable materials, such as seltzer water bottles.

Photos by Amanda Moses