We first started learning about hydroponics last spring when my aunt gave us a cutting of a Dracaena house plant. She told us to leave it in a pot of water until it grew roots. This literally took months. As of now, the roots are only a few inches long. Over the summer we experimented with adding soil and discovered that it grew better with just water. That's when we decided to look into growing methods that omit soil.
If you'd like to learn more about hydroponics on a smaller level, I'd definitely suggest the AquaFarm from Back to the Roots. It's a fish tank that allows you to also grow six plants right above the tank. You could have a mini herb garden in your kitchen! The AquaFarm is a great example of a small scale aquaponics system, which is a food production process that combines aquaculture (raising fish in tanks) with hydroponics. The fish feed the plants and the plants clean the water. This closed-loop ecosystem is also a great way to learn about symbiotic relationships in an environment!
Wikipedia image of a hydroponics system.
Wikipedia image of an aquaponics system.
To start your own hydroponics growing system, you'll need to choose your plant (it will be harder to start from seed), a bucket and/or Net Cup, a medium (could be sand, Clay, Rockwool Cubes, or nothing at all), and a nutrient rich water source (like FloraGro Fertilizer). You can easily find these materials at Home Depot, local gardening stores or even online (Amazon has some decent deals). It will cost about $30 to buy all the basic materials to start a small hydroponics system. Hydroponically grown foods are said to taste better and are more nutritious. You can also control what goes into growing them and you'll pollute less, which is good for the environment!
The method we use is the static solution culture. We plan to expand on our project in the spring and create a garden outside using plastic tubs to grow herbs and vegetables. Currently we have green onions, celery and our Dracaena plant growing on our windowsill. We do not use a nutrient fertilizer, but we will once we set up the garden outside. The green onions and celery simply regrow every time they are cut (right above the bulb or 1-2 inches above the roots). We always buy organic vegetables that we plan to regrow in our windowsill. We replace the water at least once a week and clean the roots to make sure there is no algae growth or root rot. Too much water can actually damage the roots, so I always leave a small amount of the roots above the water to aerate them. Many people who use the hydroponics method at home use a bubbler system that aerates the water for them. We use a hand pump with a tube to add air to the water once or twice a day. The kids love helping! We only do this for the Dracaena plant.
Why do we learn about hydroponics at home? We are homeschoolers and enjoy learning about science in real life situations. Life science is especially fascinating to Bean and she likes reading books about plants and how they grow (her favorites are Science With Plants and How Flowers Grow). Hydroponics is relatively low maintenance (depending on the type of system you put together and how many plants you decide to grow) and is an easy way for children to learn about growing their own plants and food. We also feel that it is important to teach them how to care for plants at a young age so they will grow up knowing how to grow their own food.
We keep track of growth by measuring the roots, stems and leaves about once a week. If we are especially busy (like in December), we will skip the weekly checks and see what the end of the month shows. We track the growth using a calendar, noting the days that we change the water (we measure it when it is out of the water on a clean surface), along with the weather for the day. This helps us compare the growth, such as slower growth on cold weeks, and more growth on warmer, sunny weeks. This spring we will finally transition the Dracaena to a large planter. In the meantime we will continue to learn about hydroponics and try other techniques to see what system works best for us!
Be sure to visit Little Bins for Little Hands to find more posts in the A-Z Kids STEM Activities Series!