How To Water Microgreens

Microgreens are effectively small versions of mature plants. They are delicious and usually 4-5 times more nutritious than the ‘adult’ version of the plant!

However, they are also more delicate. You need to make sure you learn how to water microgreens properly; it can make a big difference in their survival and growth rate.

I know what you’re thinking, watering is simple, add a little each day, perhaps finger test the soil, and that’s it! Unfortunately, you’ll need to be slightly more scientific than this in your approach. Microgreens are small and surprisingly delicate.

Water Quality Guidelines

In most situations, the water from your faucet is sufficient for the needs of your microgreens. However, you can do a simple test to see if the faucet water is as good as you think it is:

Grow to batches of microgreens, one with faucet water, and one with water from another source, such as bottled. If your faucet watered plants have leaves that are tainted yellow or curl, then you have excess chlorine in your water.

It is safe to eat these, but, the microgreens given bottled water will look and taste better.

Here are some guidelines to help ensure you have the best possible water for your microgreens:

Best ph for watering microgreens

Microgreens generally grow best in a slightly acidic environment, that’s a pH between 6 and 6.5. They can survive in the range of 5.5 to 7 but prefer the narrower, almost neutral range.

Testing your water is easy, you’ll need a pH tester strip; it will show you the pH of your water.

But, fixing it, if it is not in the right range, can be harder. A tiny bit of baking soda can reduce acidity, bringing your water closer to neutral. Alternatively, a little lemon juice can make your water more acidic. The trick is to get the balance right.


Chlorine will affect the color and the taste of your plants. Unfortunately, most water treatment works add chlorine to the water supply, it helps to kill bacteria; making the water safe to drink.

The easiest way to remove chlorine is by using a carbon filter. This can be with a filter jug, under-counter water filter in your water supply, or you can even opt for a whole house system.

The alternative is to fill a bucket with water and leave it to sit for a day, this will allow the chlorine to evaporate.

The temperature of the water

Microgreens don’t like water that is too cold. But, they also won’t do well in water that is too warm! The ideal temperature is between 50°- 60°F. It can go as high as 70°F, but anything above this and the plants will start to suffer.

A simple thermometer and a few moments of patience will ensure you get the temperature right.

Hardiness of the water

If you have hard water you’ll know because it is much more difficult to get a lather with soap. You’ll also have limescale building up on the inside of your appliances. Take a look for the white coating on the inside of your kettle; that’s a sign of hard water.

Water hardness is caused by the presence of minerals in the water; these occur naturally as the water passes through the rock on its way to the treatment works. Calcium and magnesium carbonate are the two most common minerals which cause this issue.

While it is not good for your appliances, it is beneficial for your plants. Soft water can actually slow the growth of your plants. But, hard water is more likely to be alkaline, you’ll need to check and adjust the pH for your plants.

Methods of Watering Microgreens

The key, when learning how to water microgreens, is to remember that they are small and delicate. You don’t want to pour water on top of them as this has the potential to squash and damage them.

That leaves you with 2 options:

  1. Spray Bottle

A spray bottle makes it easy to control the water quality and to ensure the plants are not saturated with water. Any spray bottle will do; providing it is clean and hasn’t had any chemicals in it.

  1. Water Tray

The alternative is to ensure there are drainage holes in your growing tray. You can then place a tray under your growing tray and add the water to this. The base of the growing medium w be sat in the water and the microgreens can access as much water as they need.

For this to be effective the growing medium must be relatively shallow, 1-2 inches is enough for most microgreens.

This will allow the roots of the microgreens to stretch to the water. All you have to do is make sure there is water in the tray.

Top Tip: If you really feel the need to water your plants in a more conventional fashion then you should add water to the side of the growing tray; directly to the growing medium. There is much less chance of damaging the plants this way.

How often to water microgreens

The soil should always be moist, but not soggy. In practice, you’ll need to monitor and water the microgreens every day.

Of course, if you use the water tray method you may find that the plants can go several days without water.

It should be noted that you may need to check, and even water the plants twice a day during the first few days after germination. This is also true if you leave the plants in direct sunlight; although this is not normally a good option.

Should I use fertilized water (hydroponics)?

Hydroponics is the practice of floating microgreens on water which has fertilizers in to give them all the nutrition they need.

It’s difficult to over water the plants as their roots float in the water all the time; taking just the water and nutrients they need.

Providing you maintain the water temp, pH and nutrient level microgreens can grow exceptionally well with hydroponics.

However, there is a clause. The plants will absorb nutrients and clean the water in the process, but you’ll need to add nutrients to the water on a regular basis. If you upset the balance you can easily kill your plants. Maintaining the nutrient levels can be costly; if you’re planning to grow microgreens for the long term you should consider using aquaponics; instead of hydroponics.

This has the advantages of hydroponics but uses fish to provide the nutrients the plants need; making it a more organic and easier to maintain option. You won’t even need to know how to water microgreens; they will get all the water they need as they need it.

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