Hydroponic gardening is a great way to grow food—without soil—in smaller spaces. Here’s what you need to know.
Whether you’re interested in growing a small food garden at home or looking at larger-scale farming, hydroponic gardening provides a way to grow fresh, nutrient-rich food, free of pesticides, in a quickly changing world with limited resources. That’s because hydroponic gardening is on water and nutrients instead of soil, a finite resource, to grow plants.
Growing hydroponically has the added benefit that it can be done in places that were previously off-limits to gardeners and farmers, like small spaces and areas without healthy soil. It also typically uses less water than traditional gardening and farming. Different types of hydroponic gardening systems are available, making it accessible to anyone who would like to grow some of their own food—hello, year-round leafy greens and herbs!
“Hydroponic gardens are a part of the future of agriculture,” says Lance Beecher, PhD, aquaponics, aquaculture and fisheries specialist at Clemson University. “With limited space and resources, mainly water, hydroponics can fill a niche within agriculture where food can be grown in areas not thought of before and provide fresh food to places where people need it the most.”
If you’re curious about the easiest foods to grow at home or want to create a container garden or vertical garden, rest assured that you can grow your own food regardless of how much space you have. Consider some of these hydroponic garden kits so you can have a fresh and continuous supply of sustainable food.
What is a hydroponic garden?
Because a hydroponic garden uses water instead of soil, plants can grow indoors, year-round, in less space than traditional soil-based gardens. This means if you live in a tiny apartment or don’t have an outdoor area, you can still grow fresh food, such as leafy greens and herbs. Hydroponic grown plants usually grow faster, can yield a bigger harvest than plants grown in soil and use less water. You can purchase a ready-to-go hydroponic garden or build your own. Here’s what you need to know about DIY hydroponics.
How does hydroponic gardening work?
Plants need sunlight, water and nutrients to grow. Typically, plants get nutrients from soil, but “the basis of hydroponics is rooted in growing the food in nutrient-enriched water,” says Rick Vanzura, CEO of Freight Farms. A hydroponic system can be programmed to ensure a plant receives adequate water, nutrients, light and even the correct pH level to provide each plant what it needs to survive and thrive.
Depending on the type of hydroponic system, roots are placed either directly in the water with dissolved nutrients or in a growing medium, such as clay pebbles, perlite, peat moss or coconut fiber, where they will receive all the nutrients they need to grow. If you’ve been learning about organic food, you can grow and harvest your own with a hydroponic garden.
What plants can grow hydroponically?
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A variety of different foods can be grown in a hydroponic garden. Microgreens are among the easiest plants to grow. “Microgreens are resilient and more cost effective to experiment with, making them the ideal trial-and-error crop,” says Vanzura.
Similar to what you can grow in a backyard hanging garden, “the more popular vegetables grown in hydroponics include leafy greens and lettuces,” says Beecher. However, more complex systems can produce fruiting vegetables such as tomatoes, cucumbers, peppers and more,” he says.
You have to consider which plants can do well in a small space and don’t weigh too much.”Hydroponic farms typically support produce that thrives in nutrient solution and isn’t too heavy to be grown vertically,” says Vanzura. But if you’re interested in growing root vegetables, such as beets, potatoes or even kohlrabi, you’ll need to plant them in soil. Beecher explains that growing tuber vegetables in a hydroponic setting is nearly impossible, though Vanzura says his hydroponic farm is able to grow radishes and turnips.
What are the benefits of a hydroponic garden?
In addition to being able to grow food without soil and in small spaces, hydroponic gardening can contribute to solving social and environmental issues.
In regions with food deserts—areas where people don’t have access to fresh fruit or vegetables—a hydroponic garden or farm can be part of the solution. Hydroponic gardens “can bring food deserts and local communities fresh produce close to home at a more affordable, environmentally friendly cost, says Vanzura. “They can help to offset rising food and farmland costs and create a better way to grow some of our staple produce.”
Vanzura lists other benefits as well: “Hydroponic plants can grow 40% to 50% faster and produce 30% more than the plants growing in soil—not only growing more produce in a shorter amount of time, but also, in some cases, growing produce that is even more nutrient dense.”
What are the drawbacks of a hydroponic garden?
Like most things, hydroponic gardening does have a few downsides. For one, a hydroponic garden requires continual vigilance to ensure that the plants are receiving adequate nutrients and have sufficient water. Beecher explains that the hydroponic system can be complex and costly. There are also limitations on what grows well, so you can’t grow everything under the sun. For example, if you want to have a successful crop of potatoes or other root vegetables, you’ll need to grow them in a soil-based garden. You probably can’t grow indoor fruit trees, either. Other drawbacks, Beecher explains, include the risk of airborne diseases, as well as greater use of electricity to run the system.
How do you build a hydroponic garden?
You can build several different types of hydroponic gardens. “My choices for beginners would be the deep water culture, which can be performed using a floating raft in a reservoir or in a bucket,” says Beecher. “The designs can be constructed with relative ease and are inexpensive to start with for a hydroponic system.”
If you have more experience or want a creative project, you’ll want to consider a different system. “Individuals who are beginners but are looking for a slightly more advanced option should look to a horizontal ebb-and-flow shelf rack,” Vanzura says. “This type of setup is used for growing microgreens, and it gives you more freedom to experiment with environmental elements compared to compact systems.”
Consider the following systems before purchasing supplies.
The wick system is the easiest and simplest system to set up, with a reservoir, a growing tray and wicks. In this system, plants are placed in a growing substrate, such as perlite or a soilless mix, with the reservoir placed below. A string or rope wick connects the water-nutrient solution to the roots of the plant.
Plants that need a lot of water, such as leafy greens or tomatoes, won’t do well with this system, since it may not provide sufficient liquid nutrients fast enough. This system is good for herbs and microgreens.
What you’ll need:
- Fill up the reservoir with the liquid-nutrient solution.
- Place a couple strings or wicks at the bottom of the growing tray and connect it to the reservoir.
- Place the seedling or plant over the reservoir. The wick will transport water-nutrient solution directly to the roots when the plant is thirsty or ready.
Deep water culture system
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A deep water culture system is one of the more popular and easier hydroponic systems to use. The roots of the plants are submerged in aerated water so they receive sufficient water, nutrients and oxygen. This system requires an air pump and an air stone to keep the water oxygenated.
What you’ll need:
- Add water and nutrients to an opaque reservoir or container and fill to a depth of 12 inches or more.
- Place an air stone into the water and connect it to an air pump that is near (but not inside) the reservoir. The pump helps aerate the water so the roots receive enough oxygen.
- Cut your styrofoam to create a growing raft that can sit and float about 1 inch below the top of the container or reservoir. Cut holes into the styrofoam with enough spacing between them to allow plants room to grow.
- Next, place your plants in the net pots (also known as mesh planters) and then place the net pots in the holes on the styrofoam raft. The net pots let the plants’ roots grow out of the bottom and the sides, so they have easier and better access to nutrients and oxygen. The roots of the plant need to be submerged in the aerated water of the reservoir. If they don’t receive sufficient oxygen, the roots can drown.
Ebb and flow
This system is more technical and complex but also offers greater versatility. It functions by flooding and draining the reservoir periodically, based on the needs of the plant, its growth cycle and even the air temperature. During the flooding process, oxygenated water moves through the system and provides hydration and nutrients to the plants. When it drains, the water nutrient solution goes back into the reservoir to be used again. A pump is necessary to flood and drain the growing tray.
What you’ll need:
- Place the reservoir directly below the flood tray. Place your seedlings in pots with plenty of drainage holes and ensure the pots are taller than the flooding tray.
- Use a fill tube and drain tube to connect the reservoir to the flood tray. The other end of the fill tube connects to the submersible pump, which allows you to set a timer and control the flooding. The drain tube is on gravity to drain the water back into the flood tray.
- Set up a submersible pump and use the timer to schedule how often to flood and drain the plants.
Should you build or buy a system?
Choosing whether to build or buy a hydroponic garden system comes down to personal preference, patience and time. Consider whether you want to spend time DIYing or prefer the ease of purchasing a ready-made hydroponic garden. If you have an engineer’s mind or want a project, building your own hydroponic system can be fun, rewarding and slightly less expensive than purchasing a ready-made system.
If you want to start growing immediately and want to see if hydroponic gardening is a good fit for you, opt for a premade system. “Countertop hydroponic systems are a good starting point to explore how light and water affects plants grown hydroponically,” says Vanzura. “These systems are built for beginners and usually include add-in nutrients, which is a good way to understand which nutrients are needed for plants to thrive and why, and at what levels.”
Tips for maintaining your hydroponic garden
Beecher recommends having patience and being willing to learn from mistakes before embarking further into hydroponics. Beecher and Vanzura offered a few more of their best tips for hydroponic gardening:
- “One of the most important things you can do to maintain a hydroponic system is to change the water on a consistent basis,” says Vanzura.
- “It’s also important to practice taking sensor readings for electrical conductivity (EC) and pH to ensure your nutrients and pH-down are dosing correctly,” Vanzura says.
- “Always gather as much information as needed before diving in,” says Beecher. “Information from reputable sources is vital for success.”
- “Understanding the relationship between the plant and the nutrients is essential to success,” explains Beecher.
- “Build a small, inexpensive system and get used to the new growing technique,” says Beecher.
Want a few more ideas about getting started? Be sure to read these gardening tips for beginners.