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How To Grow Hydroponic Garden Herbs (In Mason Jars)

There are many reasons you may wish to grow plants indoors. Whether it is winter and plants can’t survive outdoors, or you simply don’t have the outdoor space, indoor growing can be a great remedy.

I particularly like to grow certain herbs indoors hydroponically to have year round harvests. Almost any herbs can be grown in hydroponics, and the process is easy to set up. It is also clean and tidy when compared to growing in soil.

So, in this article, I’ll teach you how to grow hydroponic garden herbs in mason jars, any time of the year. This can be a fun winter project, or a simple way to have your favorite herbs within arms reach in the kitchen. Let’s get started!

Ball just setup with net cup and herbs
Young basil plant growing in a small hydroponic container.

Growing Garden Herbs in Hydroponics 101

First, I want to give a quick overview of hydroponics. If you are new to the idea of growing plants in water, this is worth reading.

Hydroponics is a method for growing plant in a water-based solution instead of traditional soil. Liquid nutrients are added to the water, and can be combined with various media, such as coir, perlite, or vermiculite.

Pros and Cons of Hydroponics

There are benefits and drawbacks to growing plants and herbs hydroponically. Many commercial grow operations use hydroponic setups, while others use open land with native soil.

Pros:

  • Clean and soil-free
  • Little or no watering
  • Faster growth rate
  • Cheap to get started

Cons:

  • Most nutrients are not organic
  • pH levels should be monitored
  • Salts build up over time
Cilantro growing in a large-scale hydroponic system.

Types of hydroponic systems

There are numerous techniques for growing in hydroponics, ranging from super simple to highly complex and technical. For growing herbs, we’ll focus on a simple method called ‘Kratky’ hydroponics, but feel free to explore the other methods listed below!

Kratky hydroponics. We love the Kratky method of hydroponics for its simplicity and effectiveness. Essentially, the plant roots are partially submerged in nutrient-rich water without any circulation or added airflow. The rest of the roots are above water where they can get oxygen.
*This is method we use in this article.

Ball jar with hydroponic net cup
Basic Kratky hydroponics in a ball jar.

DWC hydroponics. Deep water culture (DWC) hydroponic systems are similar to Kratky, but introduce aeration into the water. A pump and air stone is typically used to infuse the water reservoir with bubbles. When the bubbles reach the top, they help moisten the roots and improve oxygenation. Root systems can develop to be larger and/or faster growing, but the system is more complicated than Kratky.

DWC hydroponic ball jar bubbles
DWC hydroponic ball jar with bubbles.

Pre-built systems. One of the easiest ways to get into hydroponics is to buy a pre-built system. The most popular option is the Aerogarden, though other similar products exist. Most are as simple as plugging them in, adding water, and waiting for the plants to grow. For growing herbs indoors, these are an excellent, aesthetically pleasing option.

Click and grow hydroponic system with plants
Click and Grow system.

Wick systems. In a wick system, the plant roots don’t actually reach down into the water. Instead, the roots grow in a substrate (such as rockwool or coco coir) and a wick pulls water from a reservoir of hydroponic nutrients. This keeps the root systems confined to a set container size, while the water source can be as large as necessary. The Click and Grow systems use a wicking setup.


Growing Garden Herbs in Hydroponics (How To)

Any of the systems mentioned above can be used to grow hydroponic herbs. However, in this article, we will use the Kratky method. This system involves the fewest materials for setup, and is very low maintenance.

Setting up a Kratky hydroponic container

To set up a Kratky hydroponic container, you’ll need some basic supplies. Most are re-usable, and you can even use recycled plastic containers to create makeshift containers.

We like growing in ball jars since they come in a variety of sizes, and can be reused again and again for new plants. However, leftover plastic food containers work too, and the same principles apply.

Supplies:

  • Hydroponic nutrients
  • Wide-mouth ball jars or mason jars
  • 3″ net cups
  • Seed starter plugs (such as Rapid Rooters)
  • Clay pellets
  • Tin foil
  • Seeds
3 inch net cup in ball jar
Net cups suspend plants, allowing roots to grow through into the water below.

It may seem like a lot of supplies, but in hydroponics, this is pretty simple. The essentials are the a container that is large enough to grow a full-sized plant, net cups to hold the plants in place, and quality nutrients.

Growing hydroponic herbs in mason jars

  1. Sow seeds.

    The first step is to plant your herb seeds. We’ll be growing basil, thyme, and oregano in hydroponics, but you can grow virtually any plant you want. Rapid rooters are great for germination, but rock wool is another popular choice for hydroponics. Do not use soil for germination, as it can leech into the water and become messy.Rapid rooter plug

  2. Set up the mason jars.

    Surround the ball jar with tin foil to block out light (this avoids algae growth in the water). Place the net cup into the jar. Remember, you can use an alternate container, so long as your net cups can be held up.Ball jar hydroponic basil

  3. Mix and add nutrients.

    Most hydroponic nutrients are concentrated, so a little goes a long way. Don’t over-do it, and just follow the directions on the packaging for best results. Our nutrients require 1 teaspoon (5ml) of nutrients per gallon of water. Fill the jar with nutrient water up to the base of the net cup.Dyna Gro Grow Hydroponic nutrients

  4. Add plants to the container.

    Once your plants have sprouted and are about 1-2 weeks old, the roots should be poking through the seed plugs. This is the best time to transfer them to the hydroponic system. Hold the seedling in the center of the net cup and surround it with clay pebbles to hold it in place. Basil in hydroponics with clay pebbles

  5. Add more water.

    Add a bit more water to the container until it is just touching the base of the seedling’s root system. This will ensure the roots can access water and nutrients to continue growing.

  6. Place the plants in a bright location.

    We use grow lights, but this isn’t always necessary. If you have a bright South-facing window, your plants will grow (albeit slowly). For the best results, invest in a quality LED grow light.Hydroponic basil plant in ball jar

  7. Watch the water level.

    Over time, the herbs will grow larger, and the roots will grow deeper, using more and more water. We don’t recommend adding more water until the level is around 75% used up. Ensure that the roots are always partially submerged in water, but that the air roots remain above the water.

That’s it! What’s incredible about this method of growing herbs in hydroponics is that it doesn’t require any complicated aeration equipment. From this point on, the roots will grow deeper into the water, drinking it as needed.

Best herbs for growing in hydroponics

While virtually anything can be grown in hydroponics, we do have our favorite herbs for this growing method. If you want to grow something outside the box, feel free to try and let us know how it goes!

  • Basil
  • Thyme
  • Cilantro
  • Parsley
  • Oregano
  • Rosemary
  • Mint

Tips for growing hydroponic herbs

While Kratky hydroponics is the simplest form of hydroponics, you can still run into issues along the way. Here are a few tips to keep your herbs on track:

  • Don’t add water unless necessary. The roots should have no trouble growing downwards faster than the water is used up. If your plants are drooping or look sad, check on the water level to make sure the bottom of the roots are touching the water. Top it off with nutrient water if needed, but never completely submerge the roots!
  • Use ‘grow stage’ nutrients. You may find there are different types of nutrients available. For herbs, a ‘growth stage’ fertilizer is best, as opposed to ‘bloom’ or ‘flower’ formulated nutrients.
  • Monitor pH. If your plants seem to struggle, you might want to invest in a simple pH testing kit or unit. These are relatively cheap and can help you adjust pH to the ideal range between 5.5-6.5 for most herbs.
  • Provide consistent light. Most herbs grow best in full sun conditions. To emulate this indoors, I highly recommend using a grow light. You don’t need anything too strong, but try to give the plants 16 hours of light daily, and 8 hours of darkness.

We have grown all kinds of hydroponic herbs in jars, like basil, oregano, thyme, and cilantro, with great results! I hope this article inspires you to try growing herbs indoors in water.

Jeff

Wednesday 21st of December 2022

Can I grow jalapenos this way?

Geeky Greenhouse

Wednesday 28th of December 2022

Yes, just be sure they are in a warm spot and the mason jar is large enough to support a bigger plant. I'd recommend at least a half-gallon mason jar with the wide-mouth lid.