How To Grow Watercress In Aquaponics

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Last Updated on October 30, 2022

Watercress is one of the easiest and healthiest plants to grow in your aquaponics garden. So, if you’re wondering how to grow watercress in aquaponics, you’ve come to the right place.

Watercress is a water-loving plant and it is popular for its tasty flavor when added to meals. They are great for adding spice to your soup, fresh salad mix, as well as a sandwich.

This article attempts to give you the details on how to grow watercress for your aquaponics garden. So let’s begin.

Why Grow Watercress In Your Aquaponics Farm

Being a water-loving plant, you can agree it is one of the best leafy green plants to grow in your aquaponics garden. Watercress is a highly nutritious and fast-growing plant. For this reason, watercress is one of the most loving plants to grow especially among commercial hydroponic and aquaponics growers.

Also, growing watercress for your aquaponics garden will be an amazing way of introducing newbies to the world of aquaponics.

Why Grow Watercress In Your Aquaponics Farm

2 Ways To Grow Watercress In Aquaponics

You can grow watercress easily by planting from their seeds or you can simply grow them from cuttings.

1.    Propagation From Seeds

Watercress propagation from seed should begin to show germination between a couple of days or two weeks.

Plant about 10 to 15 seeds in the net pots growing medium. The seeds will begin to sprout from 3 days and continue to grow for 4 to 5 weeks. Then ready for harvest.

2.    Propagation From Cuttings

Watercress can be grown or cultivated from its aerial roots where the nodes of the matured plants are.

Cut the stem of the watercress and take away the lower parts of the leaves. Lay the cuttings on your aquaponics bed and watch them give rise to new roots in a couple of days.

You can also obtain bunches of watercress stem from grocery stores.

Guidelines On How To Grow Watercress In Aquaponics Successfully

Having decided the method of propagation (either seeds or cuttings), we can now look into the specifications and guidelines to follow. Below are the guidelines on how to successfully grow watercress in an aquaponics garden:

  1. Fish Choice: first things first, choose the appropriate fish you wish. Tilapia, trout, and catfish are the best options if you want a smooth and easy aquaponics process. Also, you should accurately calculate the number and proportion of fish to the water tank. For example, the standard rule is one matured fish per 5 gallons of water.
  2. Water Tank Setup: do the normal aquaponics tanks set up. Place your pump inside the water tank for aeration.
  3. Grow Media: choose an appropriate growing medium for your plant. You can use grow media such as hydroton, rock wool, etc. Remember watercress plants are water-loving so ensure the growing medium used can absorb water.
  4. Spacing: ensure you give your plants adequate spacing. This is so they don’t compete with nutrients from overcrowding. Space them around 9 to 12 inches apart.
  5. Temperature: watercress will do well in a temperate environmental climate. Temperature range from 50 degrees to 60 degrees Fahrenheit will be ideal.
  6. Sunlight or Grow Light: watercress herbs thrive in full sun. However, if you’re growing them indoors, they will do well under high output grow lights.
  7. pH Range: the appropriate pH range for the watercress plant is a slightly acidic and slightly alkaline environment. Therefore, the pH range will be between 6.0 to 7.5. Always test your solution so you can keep track of the nutrient levels.
  8. Fish Feed: you can start with fish pellets as these pellets comprise the complete nutrient balance for your plants’ growth. They contain vitamins, proteins, carbohydrates, and minerals.
  9. Bacteria: another important thing is you should encourage bacteria. It is this bacteria that will convert the fish waste in ammonia into nitrates for plant use.
  10. Add Watercress Plant: lastly, plant your watercress either by seed germination or by cuttings and watch them grow.

Self-Cleaning Fish Tank That Grows Food, Mini Aquaponic Ecosystem


What can you grow watercress?

Watercress is a popular, easy to grow green vegetable. It has been cultivated for centuries and is an excellent source of vitamins A, C, E and K. You can grow it in your garden or even in a pot on the patio. This perennial plant grows well in moist soil. It is very adaptable to a variety of growing conditions. Watercress grows best in water or soil with a high humidity content.

You can grow watercress in a pond, but it will have to be kept in a container if you don't want it to escape the pond.

Why is watercress good for aquaponics?

Here are a few reasons why watercress is such a great plant for aquaponic systems: It’s easy to grow – Watercress can be grown in any garden or window box and can be planted directly into the aquarium.

Watercress also does well in containers, but the roots tend to spread out more than they do in the soil. It’s low maintenance – Watercress can be harvested regularly without much effort. If you don’t like the taste of the leaves, you can just harvest the roots. Watercress is a fast growing plant that can be harvested within 6-8 weeks. It’s drought tolerant – The roots are able to withstand dry conditions and will continue to grow even if there is not enough water available.

Watercress is very easy to grow – It doesn’t require much attention and it is quite forgiving when it comes to temperature fluctuations.

How long does watercress take to grow in aquaponic?

It takes approximately one month to grow in soil and two weeks in aquaponics.

Watercress has small, thin leaves that are rich in vitamins and minerals.Watercress is native to the Mediterranean region and grows best in fertile soil with good drainage. The plant can grow up to 4 feet tall.

What’s the main concern when growing watercress in aquaponic?

It's possible to grow watercress in aquaponics but you have to be careful to maintain a healthy balance of bacteria and plants. If you don't, the bacteria can cause the plants to die. The bacteria are what converts nitrate into nitrite which is what you need for the plant to be able to uptake the nitrates from the water. The plants also require nitrate so the bacteria are essential.

Final Note

Having said all these on how to grow watercress in aquaponics: you should know there are other little precautions to be taken for a smooth aquaponics watercress garden. Things like:

  • Monitoring the activities of your fish daily.
  • Observe their feeding pattern.
  • Avoid overfeeding so you don’t clog your aquaponics system and create excess waste that your plant can absorb. Watercress does not do well in clogged or stagnant water. The water needs to be flowing, well circulated, and aerated always for optimal production.

With that said. We do hope you’ve learned some things on how to grow watercress for your aquaponics garden.

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