Hydroponic Gardening Is the (Brilliant!) Secret to Growing More Plants in Less Space

updated Jun 29, 2024
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head on shot of assorted hydroponic plants on plant stands, against a pink wall
Credit: Alex Lepe

If you’re looking for a way to add more plants to your home — whether they’re low-light-friendly houseplants or high-light-needed edible plants like herbs or vegetables — you might find that a major holdup is simply the amount of space you have. Fortunately, there’s a way to grow plants that requires no soil and can often be done in much less space: hydroponic gardening.

While plants are traditionally potted in nutrient-rich soil, they don’t strictly need to be. “Hydroponic gardening is the process of growing plants using water-based solutions instead of soil,” says Hilton Carter, a plant expert and Apartment Therapy’s resident Plant Therapist, who recently published The Propagation Handbook.

Hydroponic gardening systems can range from very low tech to very high tech (and very pricey), but if you’ve only ever grown plants the traditional way you might be a little intimidated. But don’t let the intimidation factor stop you! Below, Carter and a two other experts weigh in with tips on how to get started with hydroponic gardening.

What Is Hydroponic Gardening?

The etymology of the word hydroponic also gives clues to its definition. “Hydroponics stems from the words’ hydro,’ meaning water, and ‘ponos,’ meaning work,” says Shelley Matthew, the CEO and founder of FullCircle26, which offers supplies and education surrounding growing plants hydroponically.

Hydroponic means “working water,” and nutrients are typically dissolved in the water to feed the surrounding plants. 

What Types of Hydroponic Gardens Are Available?

The options for hydroponic gardening range from very simple (plants in water) to very complicated. Here’s what to know about each type.

Credit: Alex Lepe

Water-Only Hydroponic Gardens

The most basic form of hydroponic gardening is just plopping a plant in a container filled with water and periodically adding a nutrient mixture.

Credit: Alex Lepe

You can use a plant you’re already propagating in water, or you could transition a soil plant to water by thoroughly washing the roots in distilled water before placing the plant in a container filled with water that’s supplemented with nutrients.

The advantages of this method: It’s wildly easy and requires minimal effort, and you likely have everything you need already.

Credit: Alex Lepe

The disadvantages: If you don’t thoroughly wash the roots before adding the plant to water, the leftover organic material could lead to root rot.

Another issue with the plant-in-water method is that the roots could lack sufficient oxygen to keep them healthy. Some experts advise leaving the top bit of roots exposed to help with this issue.

Credit: Alex Lepe

Lightweight Expanded Clay Aggregate (LECA) Hydroponic Gardens

If you want to grow soil-less plants but want something that approximates the look and style of soil, LECA — porous balls of clay used to fill planters — might be for you.

To plant in LECA, make sure you wash the roots of your plants thoroughly to remove any organic matter (again, this decreases the chances of root rot).

Credit: Alex Lepe

Before using, soak the LECA balls per the instructions on the packaging. Partially fill your container with the balls before adding your plant, then gently add the rest of the LECA. You’ll need to top off your container with water and a nutrient mixture formulated for hydroponic gardening to keep plants healthy.

Nutrient Film Technique (NFT) Hydroponic Gardens

Growing plants hydroponically via the NFT technique involves continuously flowing a thin layer of nutrient-rich water over the plant’s roots.

“The roots absorb nutrients directly from the flowing solution, while excess water is recirculated back into the reservoir,” Carter says.

While it’s an efficient use of water and nutrients due to water recirculation, it relies on electricity, meaning that pump failures or power outages can harm your plants.

Carter recommends using NFT for herbs and leafy greens and avoiding this technique for large plants with extensive root systems.

You can DIY a NFT hydroponic garden using PVC pipes, or you can buy low-tech kits that come with everything you need to build. The Gardyn system is a high-tech version of the NFT system.

Wick System Hydroponic Gardens

The wick system is popular due to its passive nature and is one of the most low-maintenance type of hydroponic growing. “It doesn’t require pumps or electricity, and it’s pretty simple to set up,” Carter says.

The structure typically involves a wick that transfers water and nutrients from a reservoir to the plant, which is potted in a non-soil grow medium like vermiculite, perlite, or coconut coir.

One con is that the limited nutrient delivery isn’t ideal for large or rapidly growing plants, and wicking also causes plants to grow more slowly than other systems. This method is best for herbs and leafy greens.

You can buy basic pots with wick systems for a few bucks each, but fancier (and more expensive) versions are available, too — like this one from West Elm.

Deep Water Culture (DWC) Hydroponic Gardening

According to Carter, a DWC hydroponic garden is inexpensive and straightforward to set up.

“In this method, plants are suspended in a container filled with nutrient solution,” Carter says. “An air pump is used to oxygenate the water, preventing root rot and ensuring consistent oxygen supply.”

Unlike a wicking system, a DWC promotes rapid growth by giving roots constant access to nutrients and water.

However, you should monitor nutrient levels closely, as root rot can occur if oxygen levels drop. Carter also advises using a DWC for smaller plants with less extensive root systems.

AeroGarden planters are an example of a DWC system that’s suitable for kitchen countertops and other small spaces.

Drip System Hydroponic Gardening

A drip system may be the answer if you have raised beds or a penchant for a large garden. Water is delivered over a period of time via a continual timer base, which is ideal for plants that require specific nutrients.

A big pro is that a wide variety of plants do well on a drip system, but this setup is also expensive and prone to clogging thanks to all the additional pipes required. “Regular maintenance and cleaning is a must for this method,” says Carter.

While you can buy systems for this method of hydroponic gardening, they’re going to cost you hundreds of dollars.

Aeroponic Gardening

Aeroponics is similar to hydroponics, yet the difference is that the roots are misted instead of submerged in water.

Susan Brandt, the resident plant expert at Blooming Secrets, says that aeroponics is a highly efficient method of sustaining plants.

“This method provides excellent oxygenation to the roots, resulting in fast growth and increased yields,” she says. The negative aspect of aeroponics is that it’s complex and more challenging to maintain than traditional hydroponic methods.

The Nutraponics system relies on aeroponics.

What Types of Plants Can You Grow Hydroponically?

Carter, Matthew, and Brandt contributed their lists of favorites, which include several herbs that can be clipped for cocktails, teas, and everyday culinary creations.

  • Basil 
  • Mint
  • Oregano
  • Thyme
  • Parsley
  • Cilantro
  • Chives
  • Dill
  • Rosemary
  • Lavender
  • Sage

Houseplants are also an excellent option for growing hydroponically, as cuttings are often started in water and can thrive that way. Here are several that our experts recommend.

  • Pothos
  • Peace Lily
  • English Ivy
  • Philodendron
  • Coleus
  • Fiddle Leaf Fig
  • Begonia
  • Geranium
  • Spider Plant
  • Jade

One piece of good news is that if you are short on space, there are several easy-to-grow vegetables that do well in a hydroponic environment. 

  • Lettuce
  • Spinach
  • Tomatoes
  • Cucumbers
  • Peppers

FAQ About Growing Hydroponic Plants

Do hydroponic plants need to be given additional nutrients?

According to Carter, the answer is yes. “Hydroponic plants need additional nutrients since they are not planted in soil, which is how they usually take up nutrients,” he says. Adding this extra nutrition is simple—mix fertilizer into the water solution for an extra boost.

What type of water should you use?

Regular tap water can often work, but experts say that distilled or filtered water will give the best results.

How often should you change the water? 

Water contains oxygen, which can deplete over time, so changing the water every two to three weeks is essential.

How big can hydroponic plants get? 

The size of your plants depends on the type you have, but Carter says they’ll grow as big as you allow them to. If you have plants with large fruit, such as tomatoes or squash, you may have to enlist the help of cages to keep your plants upright.

What are the advantages and disadvantages of hydroponic gardening?

According to Carter, there are many pros and cons to consider before starting a hydroponic garden.

Advantages of Hydroponic Gardening:

  • Reduced pest issues
  • Efficient use of water and nutrients
  • Saves space
  • Suitable for indoor gardening
  • Cheaper alternative to soil

Disadvantages of Hydroponic Gardening:

  • Costly initial setup for some systems
  • Can be vulnerable to power outages
  • Requires careful monitoring
  • May increase water and eclectic bills
  • May harbor algae

How to Grow Plants Hydroponically with the DWC Method

Although there are several ways to grow plants, Brandt recommends starting with the DWC system.

“This beginner-friendly system is easy to set up and requires minimal maintenance, making it perfect for those new to hydroponics,” she says.

The setup typically consists of an air pump, air stone, reservoir, and net pots to hold the plants so their roots remain submerged in oxygenated water. To get started with a DWC system, follow Brandt’s simple steps.

1. Choose a Suitable Container

Select a container that can hold water and has enough space to accommodate your plants. It should be lightproof to prevent algae growth.

2. Set Up the Air Pump and Air Stone

Place the air pump outside the reservoir and connect it to an air stone inside the container. This will ensure proper oxygenation of the water, promoting healthy root growth.

3. Prepare the Nutrient Solution

Mix the appropriate amount of hydroponic nutrients with water according to the instructions provided by the manufacturer. Ensure the solution is well-balanced and suitable for the specific plants you intend to grow.

4. Place the Net Pots

Fill the net pots with a growing medium such as perlite or expanded clay pellets. Insert your plant seedlings or clones into the net pots, ensuring their roots are in direct contact with the nutrient solution.

5. Maintain Water Levels and pH

Monitor the water levels in the reservoir regularly and top up as needed to ensure that the roots remain submerged. Additionally, check and adjust the pH level of the nutrient solution to maintain optimal plant health.

6. Provide Adequate Lighting

Position grow lights above your plants to provide sufficient light for photosynthesis. The intensity and duration of light exposure will depend on your plant’s specific requirements.

7. Monitor and Adjust Nutrient Levels

Regularly check the nutrient solution’s strength using an electrical conductivity (EC) meter. Adjust the nutrient levels accordingly to ensure your plants receive the right balance of essential elements.

8. Monitor Plant Health and Growth

Watch your plants closely for signs of nutrient deficiencies, pests, or diseases. Adjust the nutrient solution or take appropriate measures to address any issues promptly.

Credit: Alex Lepe

How to Grow Plants Hydroponically, Starting from Propagation

Most propagation is done by starting plant cuttings in water only. Here’s how to transition that cutting to a hydroponic setup.

Credit: Alex Lepe

1. Snip a small cutting from your chosen plant.

Pick a plant that you know will root in water. (See above for expert picks.) Cut off a section just below the leaf, making sure to include a node. That’s where the plant’s natural rooting hormone is active, and the node will eventually become roots.

Credit: Alex Lepe

2. Place the plant segment in a glass container with water.

While the cut is still fresh, place the cutting in water. Choose a vessel with a thinner neck that will support the stem of the plant.

Because the new plant will receive all of its nutrients from the water, the type of water is key here. Use bottled spring or well water rather than tap water, which is often stripped of nutrients thanks to filtration and chlorination.

3. Watch for signs of rooting.

Rooting typically begins after two weeks. When the water runs low, top it off with some more bottled water. After the roots develop, begin to feed your plant with a nutrient mixture formulated for hydroponic gardening; follow the dosing instructions on the package for best results.