How to Grow Hydroponic Spinach in Kratky Method | Kratky Spinach

Last updated on October 28th, 2022 at 04:02 pm

Growing Spinach in Kratky Method | Kratky Spinach

In this post, I am going to share the techniques I use to grow Hydroponic Spinach at home using Kratky Method. Kratky Method is one of various methods of growing vegetables in Hydroponics. Other methods of growing Hydroponic Spinach include Deep Water Culture, Ebb and Flow, Nutrient Film Technique, Substrate Hydroponics, etc.

You can also check my post on growing hydroponic spinach in NFT if you want to grow spinach using Nutrient Film Technique.

What’s unique about Kratky method is that you don’t have to worry about changing Nutrient Solution or providing aeration or even recirculating Hydroponic Nutrient Solution

It is often called as Set and Forget method because once you get this system ready then you don’t have to maintain it and only come back for harvesting. Only thing you have to take care of is that there should be enough nutrient solution in the reservoir or container to last until plants are required to produce

Kratky method was developed by Dr. B.A. Kratky and has been used to grow so many vegetables since then

Materials required to Grow Spinach in Kratky Method

To grow spinach hydroponically in kratky, we need :-

• A container with or without lid
• 2 or 3 Inch Net Cups
• Cotton Wick (Optional)
• Growing Media (Cocopeat)
• 1.5 Inch thick Thermocol Sheet (Optional)

For Kratky spinach we need a container that is large enough to hold total quantity of nutrient solution spinach plants are going to need until termination because we don’t change or top off nutrient solution in kratky so it’s important that we choose the container wisely

Also, if the container comes with a lid then you can drill a hole in that lid to place the net cups otherwise something else like Thermocol sheet is required to cover the container from top and to place the net cups in

Although, you can still grow Hydroponic Spinach in Kratky even if the container is small. You’ll just have to top off nutrient solution at intervals.

In my case, I had an old plastic crate (35-40 Liters capacity) with me which is used in storing vegetables and other produce. It had holes so I also needed a black polythene sheet to line that container from inside in order to store nutrient solution.

Since my container has holes, I had to line it with black polythene sheet to avoid leakage and store nutrient solution but when I put nutrient solution in the container then I found out that black sheet was bit torn and solution was leaking.

Therefore, I had to put one more layer of polythene sheet (this time transparent one) to store nutrient solution

Since my conatainer didn’t have any lid, I had to use thermocol sheet to cover the container from top and also to place 3 inch net cups. Below you can see how I drilled holes in the thermocol sheet with 3 inch round drill saw

After drilling holes in the thermocol sheet, it was turn to fill growing media in net cups for seed germination and to grow Hydroponic Spinach. I used cocopeat to grow spinach in hydroponics kratky method as it holds moisture and is very cheap in India as compared to other growing media options

Before filling growing media in Net cups, I put a cotton wick in the net cups with two ends hanging from the bottom so that going forward they provide moisture to the growing media and keep it wet until roots touch the nutrient solution

You can choose not to use wick and instead keep nutrient solution level half inch above from the bottom of the net cup so that it keeps the growing media wet until roots have the chance to touch the nutrient solution

I filled the net cups with cocopeat leaving half inch space from the top and then sprinkled spinach seeds over cocopeat. After sprinkling the seeds, I covered them with enough cocopeat to hide them. You should not bury spinach seeds deep. 1/2 inch is enough

Before placing Net cups in kratly system, Water had to be added to kratky container so after lining the kratky container with polythene sheet I filled with plain R.O. water with EC around 0.03 ms/cm or TDS 15 ppm

Now, it was time to place all net cups in their respective holes and then to placed over the container

Germination and Growth of Kratky Spinach

Five days after I placed the net cups in kratky system, seeds started germinating. You can see below how well the germination took place

Soon after germination spinach roots were visible and trying to reach for the nutrient solution. Below you can see roots trying to pop out of Net cups

Since we are growing Hydroponic Spinach in Kratky method, I was not going to do anything but wait for spinach to grow and be ready for harvesting. You can see below for more growth updates at different dates

Harvesting Hydroponic Spinach in Kratky System

30 days after I sowed spinach seeds, Hydroponic Spinach was ready for it’s first harvesting. You can harvest spinach leaves all at once and leave the plants to regrow or you can clip individual leaves if you don’t want harvest all at once. I harvested all leaves at once and got two more harvests each at 7-10 day interval

Know more about Hydroponic Spinach Yield Per Plant

Hydroponic Nutrient Solution for Hydroponic Spinach in Kratky

To grow Hydroponic Spinach in Kratky, I use my own Leafy Greens nutrient solution formula which works really well for all leafy greens such as Hydroponic Lettuce, Coriander, Mint, etc. Leafy greens require lots of Nitrogen for their vegetative growth so this formula is rich in Nitrogen and well balanced as far as other nutrients are concerned

You can also Click Here to know how to prepare Hydroponic Nutrient Solution. Here is what’s required to make 100 Liters of Hydroponic Nutrient Solution for Kratky Spinach :-

Dissolve each fertilizer well before moving on to other so that there is no adverse chemical reaction.

Kratky Spinach EC or TDS

In kratky method we don’t usually top off nutrient solution so with time when plants consume nutrient solution , the solution becomes concentrated and EC or TDS rises. Therefore to compensate that rise we have to keep EC at reasonable levels so that it doesn’t go over recommended range

EC at the beginning of the grow was set around 1.1 ms/cm or TDS 550 ppm so that even if it gets concentrated it doesn’t go above 800-900 mark

Kratky Spinach pH

pH of nutrient solution was set at 6.2 so that even if the solution gets acidic in time, pH doesn’t dip below 5.5 mark

You can also watch my YouTube video on How to grow Spinach in Kratky Method for more information :-

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