Introduction to Growing Watercress Hydroponically
Watercress (Nasturtium officinale) is a versatile and nutritious leafy green that absolutely loves water and can thrive in hydroponic systems.
Known for its distinct peppery flavor and high nutritional content, watercress is a popular choice for salads, sandwiches, and soups.
Growing watercress hydroponically is quite easy and will allow you to enjoy a continuous supply of fresh, vibrant greens throughout the year.
In this guide, we will walk you through the steps to successfully cultivate watercress using hydroponics.
Selecting a Hydroponic System
Watercress grows very well in a number of hydroponic systems.
One of the most widely-used approaches is the nutrient film technique (NFT). NFT involves one or more grow trays with a shallow, continuously flowing film of nutrient-rich water.
Many large commercial operations use this method for maximum yield. However, NFT may not be the most practical for you.
Fortunately, there are other options to consider!
Other viable hydroponic systems include deep water culture (DWC), aeroponics, or even vertical towers.
We have laid out a detailed guide on the different hydroponic systems if you are new to hydroponics or need a refresher.
Consider your available space, budget, experience level, and personal preferences when deciding on the hydroponic system that best fits your needs.
I would personally recommend DWC for its simplicity, effectiveness, and low cost.
Many people have also had success using the Kratky Method.
Preparing the Hydroponic Setup
Start by thoroughly cleaning and sterilizing your hydroponic equipment to prevent the growth of harmful bacteria or pathogens.
Ensure the water reservoir and all components are free from debris.
You’ll want to start the nutrient solutions with the correct pH and nutrient level.
There are differing opinions on the ideal pH for watercress. Stick between 6.0 – 6.5, and you’ll be fine. Watercress will generally do fine between 5.0 – 7.0 provided the nutrients are available.
Regarding the nutrient concentration, EC of the nutrient solution should be between 1.5 to 2.0.
Growing Watercress From Seeds, Cuttings, or Starts
You have options for starting watercress in your garden. You can go with cuttings, starts, or you can grow from seed.
First, watercress can be propagated from cuttings. (This comes in really handy for getting additional gardens started after your first one!)
If using cuttings, select healthy stems and remove the lower leaves. Place the cuttings in a container of water and allow them to develop roots before transferring them to your hydroponic system.
You can also purchase young starts from a reputable nursery or grocery store. I find this method totally unnecessary as watercress is quick to sprout in as little as a few days and will grow like a weed.
Finally, you can buy seeds and start them in a paper towel or hydroponic medium, such as rockwool.
Oh, there is one more way that is quite easy – Utilize watercress leaves from store-bought salad bags! These leaves can simply be placed in a shallow tray of water. Roots will sprout within a few days, and “Voila”!
Simply transplant from the water into your hydroponic system once roots are visible. It really is that easy!
Planting in the Hydroponic System
Place the watercress younglings in the growing medium of your chosen hydroponic system.
Rockwool cubes or net pots filled with a growing medium like perlite or vermiculite work well. I personally think rockwool works extremely well with watercress.
Ensure that the roots are in direct contact with the nutrient solution to promote efficient nutrient uptake.
Providing Adequate Lighting
As usual, I recommend using LED lighting for maximum growth.
Watercress requires at least 12 to 14 hours of light per day to thrive.
Position grow lights in a way that ensures uniform coverage throughout the growing area.
I recommend you place your lights 6″ above your plants to provide coverage to all areas of the grow tray. You want to avoid the plants on the edges getting inadequate light.
Nutrient Requirements for Growing Watercress Hydroponically
Maintaining a balanced nutrient solution is essential for healthy watercress growth.
Opt for a hydroponic nutrient formula specifically designed for leafy greens.
Follow the manufacturer’s instructions for proper dilution, and ensure the solution is regularly replenished to maintain optimal nutrient levels.
Remember to keep the EC level between 1.5 and 2.0!
Temperature and Humidity Requirements
Watercress prefers cooler temperatures between 55°F and 75°F (13°C to 24°C).
Adequate airflow and ventilation are crucial to prevent excess humidity and minimize the risk of disease.
Maintain relative humidity levels between 50% and 70% to provide a favorable growing environment.
Performing Regular Maintenance
Regularly monitor the pH and nutrient levels of the hydroponic solution. Make adjustments as necessary.
Inspect the watercress plants for signs of pests, diseases, or nutrient deficiencies.
Prune any damaged or yellowing leaves to promote healthy growth.
Additionally, it is always good practice to check the hydrponic system for clogs or any other issues that may hinder water or air flow.
Harvesting Watercress
Watercress can be harvested when the leaves reach a desirable size, usually after four to six weeks of growth.
Use clean scissors to cut the stems just above the growth node leaving enough foliage for the plant to continue thriving.
You can expect to get a second crop in about 3 – 4 weeks after the first harvest.
Remember, harvesting regularly will encourage new growth and a continuous supply!
Conclusion
Growing watercress hydroponically offers an easy, convenient, and efficient way to cultivate this nutritious green.
By following the steps outlined in this guide, you can establish a thriving hydroponic garden and enjoy the fresh, peppery flavors of watercress throughout the year.
Experiment with different techniques and approaches to optimize your growing process and delight in the bountiful harvests of this versatile leafy vegetable!
Happy Growing!
Frequently Asked Questions
Can you grow watercress in hydroponics?
Yes! Watercress loves water and so naturally does well growing hydroponically in a variety of different systems.
What is the best hydroponic system for watercress?
Nutrient Film Technique (NFT) will be a great option for maximum yield. For the novice grower, I recommend DWC or even a countertop system, such as the AeroGarden or iDOO.
Can watercress grow submerged in water?
Yes, watercress is a semi-aquatic plant that can grow submerged in water. In its natural habitat, watercress typically grows along the edges of streams and ponds where its roots can be submerged while the rest of the plant remains above the water surface.
Can you grow watercress in AeroGarden?
Yes, watercress will do great in an AeroGarden or other countertop garden!
