How To Grow Spinach Indoors Hydroponically: Growing Tips

How To Grow Spinach Indoors Hydroponically: Growing Tips - LetPot's garden

Have you read many articles about growing Spinach hydroponically on the Internet, but you still need help growing Spinach well?

I can understand this feeling. We usually encounter many troublesome problems in growing Spinach in hydroponics, but after our continuous attempts, we have gained much experience in hydroponics growing system. These experiences may be helpful to you! (Recommended Collection)


Vegetables are an indispensable item in our daily diet list. We need to eat vegetables at least once or twice a day to supplement the trace elements our body needs, and Spinach is one of the vegetables with extremely high nutritional value. Maybe you don't believe me, but you must know Popeye. Although we can't gain strength like Popeye, regular consumption of Spinach still has excellent health benefits for our bodies.

Unfortunately, many gardeners are often limited by the seasons in the way they grow Spinach through the soil. Usually, they can only grow Spinach in spring and autumn. They often have little harvest because they are not experienced enough in growing Spinach, and their Spinach will become bitter. This leaves many gardeners wondering, "How do I grow spinach?"

In this article, I will list some tips for hydroponic Spinach and some good indoor hydroponic system (you can ignore them if you want to learn about growing tips). From now on, you can harvest fresh Spinach all year round. Let's start!


What is hydroponic spinach?

As you can see, I want to show you how to grow Spinach hydroponically. I don't particularly appreciate introducing too much about growing vegetables in soil because this method is too common. The way we grow Spinach ourselves is to grow Spinach through hydroponics. In this way, you don't have to worry about the influence of seasons and can harvest fresh Spinach all year round.

Growing Spinach HydroponicallySuppose you have experience in building a hydroponic system. In that case, you can quickly start growing spinach hydroponics, and you only need to read the knowledge points I describe below carefully. You can avoid many technical problems in hydroponic planting.

But if you are a novice gardener without experience building a hydroponic system, please browse my previous article:


Suppose you want to do it all in one step. In that case, you can check out LetPot Max hydroponics garden, which features innovative automatic watering and nutrition functions and integration with the app. With these features, you can start growing Spinach hydroponically without much effort, even if you are a novice gardener.

Learn about LetPot® and customer stories:


What are the best-growing conditions for hydroponic Spinach?

The indispensable conditions for growing vegetables in hydroponics are temperature, light duration, water quality, and nutrient solution. It is essential to grasp these conditions parameters, which will determine the quality and yield of your hydroponic Spinach.


The best temperature for hydroponic Spinach

The best temperature for hydroponic Spinach

Spinach is suitable for growing at lower temperatures. Usually, we will artificially control its temperature, control the temperature between 15°C to 20°C (59°F to 68°F), and ensure the stability of the temperature. You can use some temperature measuring tools to detect the temperature, and you need to ensure that there is a thermostat or holding device to control the temperature in the appropriate range.


Optimal light duration for hydroponic Spinach

Optimal light duration for hydroponic Spinach

Spinach needs sufficient light for photosynthesis. Our experience is keeping 10-12 hours of light daily so Spinach can fully absorb light to maintain healthy growth. But since I'm growing indoors hydroponically, I must use grow lights. If you are also using grow lights, you need to pay attention to the light intensity, which should be manageable. Keep a moderate intensity so as not to burn the plant leaves or cause spinach bolting. If you don't want to feel like a failure, my mistakes deserve your attention!


The best nutrient solution for hydroponic Spinach

Because we use hydroponics to grow plants, a nutrient solution is essential. Each vegetable needs a different nutrient solution. If you also grow other vegetables, I suggest you use a different hydroponic system to grow other vegetables, which is more beneficial for you to use other nutrient solutions according to various vegetables. The primary nutrients for spinach plants grown in hydroponics are calcium and magnesium, as well as the necessary trace elements such as nitrogen, phosphorus, and potassium, to maintain the EC range (nutrient intensity): 1.8-2.3.

As a note, avoid too much nitrogen, as it can cause leaf tip burn. Just before harvesting, you need to reduce the nutrient intensity appropriately to prevent the leaves from becoming bitter.


Best water quality for hydroponic Spinach

Water quality is essential when growing plants in a hydroponic system. We need to pay attention to the pH range of the water, and Spinach likes to grow in the pH range of 5.5-6.5. We usually use purified or treated water to ensure no harmful substances or microorganisms are in the water.


Here's a quick guide to the parameters for hydroponic Spinach, which you can save for later if desired:

  • Best Suitable Hydroponics Method: Any
  • Best Growing Media: Rock wool or coconut shells
  • Germination time: 5 – 10 days
  • Harvest time: 45 days
  • Optimum pH range: 5.5 – 6.5
  • Best Nutritional Combination: Any balanced combination of lettuce
  • EC Range (Nutritional Strength): 1.8 – 2.3
  • The difficulty of growing: medium easy


How to Germinate Hydroponic Spinach Seeds?

With the abovementioned experience, let's start growing our first spinach plants, assuming you already have a working hydroponic system.

Although hydroponic planting is soilless, it also needs some growth medium to help the plant roots retain water. Standard growing media include coconut shells, rock wool cubes, horticultural foam, hydroponic soil (LECA clay pebbles), vermiculite, and perlite.

We use rock wool and soak the rock wool plugs in water with a pH of 5.5 for at least 15-20 seconds to allow them to absorb the water thoroughly. 

Here is a specific step:

  1. Put 2-3 spinach seeds into each rock wool plug and place the plugs on the tray.
  2. Cover each rock wool plug with a clear dome cover (if you don't have a humidity dome cover, you can use plastic wrap instead) to avoid water loss and maintain humidity.
  3. You can remove the cover After the seeds have germinated and the first leaves grow.
  4. When the first true leaves grow, the seedlings are ready to be transferred to the hydroponic system.
  5. When you finish the above work, germination is about 6-10 days.


Harvesting Hydroponic Spinach

According to our everyday experience, if you grow Spinach hydroponically according to our method, it will mature after about 45 days, and you can start harvesting now. Of course, if you want to continue planting after harvest, you will need to use shears or pruners to cut off the stems, leaving the inner leaves intact so the leaves can continue growing and ensure you have a constant supply of fresh vegetables.


Frequently Asked Questions About Growing Spinach Hydroponically


Can Spinach be grown hydroponically?

Most vegetables can be grown by hydroponics, and Spinach is no exception. As long as you provide the necessary growth conditions for hydroponic vegetables, you only need to wait to harvest your results.


How long does it take to grow Spinach hydroponically?

The harvest time of Spinach grown in hydroponics is about 45 days. That is our current harvest time, but different spinach varieties and growing conditions may also cause other harvest times, so harvest times are for reference only.


Can I grow Spinach indoors year-round?

If you want to grow Spinach all year round, you need to choose to grow it indoors, prepare plant growth lights, and plant it through hydroponics or a hydroponic system so that all the growth conditions required by the plants are controllable. You are Spinach can be grown year-round. Simply put, this avoids the influence of different seasons and growing conditions, and you can even grow various hydroponic plants.


Can Spinach be harvested after bolting?

I suggest that you avoid this in advance. Otherwise, the Spinach you harvest will likely be very bitter. Try to gather them before bolting.


Why do Spinach seeds need to be soaked?

The purpose of soaking spinach seeds is to get them to germinate as quickly as possible, and keeping them in a humid environment is very conducive to their germination. We have done a test, and the soaked seeds only need five days to germinate, while the unsoaked seeds can germinate. Seeds can germinate for about ten days or more, and I'm sure you don't want to wait that long.



This article outlines the steps and tips for growing Spinach using hydroponics. I hope this tutorial was helpful to you.

We welcome your feedback and encourage you to share more knowledge to improve our tutorials. Please feel free to leave your comments as they help other hydroponic enthusiasts learn and achieve better results in their hydroponic gardens. Let's work together to strive for excellence in hydroponics.


Other Plant Hydroponic Growing Tips

If you are also interested in other hydroponic plants, please read related articles.

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