Sunday, June 30, 2013

Kratky Method

I've been told the Kratky Method is also good for fast growing vegetables like tomatoes.  It's not the right time of year to be growing leafy greens, but I have some heat tolerant varieties that I'm experimenting with in the shade. 

 The Kratky Method appeals to me because it is so easy.  The hydroponic system requires mixing solution on a regular basis, and AP requires monitoring.  Once filled and planted there is nothing else to do with the Kratky Method.  As the solution is used the root grow down a bit further.

The initial solution for this 16-15-32 solution in a 200 litter tank is created by mixing
104 grams Masterblend 4-18-38, 104 grams Ca(NO3)2, and 52 grams MgSo4 in 200 liters of water.

I did not think the Kratky Method would be well suited to tomatoes, but someone left a comment assuring me they also grow well.  I'm growing tomatoes in a 50 gallon hydroponic Dutch Bucket system with a 20-18-38 solution created by mixing
132 grams Masterblend 4-18-38, 132 grams Ca(NO3)2, and 66 grams MgSo4 in 55 gallons of water.
Next summer I may try tomatoes in the Kratky bed.

The units are marked in liters on the Kratky tank and my hydroponic reservoir is marked in gallons so each of the above formulas are stated differently.  The lettuce formula is not as strong as the solution mixed for tomatoes.

After 34 days, I have decided to begin posting the results of this experiment.   Below are photos of the experiment taken every few days.  This experiment was done in the hottest part of summer.  Temperatures reached 111 degrees in the shade where these plants were grown.

Kale Roots Day 34

Lettuce Roots at day 34

For more about mixing the Masterblend fertilizer go to
The idea for both the hydroponic and Kratky Method came from MHPgardener at


  1. Robert, you are soooo wrong ! I have had great success growing tomatoes using Kratky's method !

    1. That's good to know. I edited the article to indicate that tomatoes can also be grown.

  2. Robert, I checked my log book, my cherry tomatoes use about 10 gallons of fertilizer per plant, the bush about 7.5 gallons per plant ( from seed to now, approx. 5 months ) still harvesting fruit & new blossoms all the time...plan your vessel size accordingly, add solution when need, and enjoy the benefits of EASY tomato growing with the Kratky method

  3. A little know fact in the Kratky world is that as the water goes down, it can be replenished. Just mix some formula and add to the container about once a week. The trick is to draw a line on the inside of the container when there are water roots as well as a or roots. Never fill over the line. I was axle to grow a watermelon in a 1 gallon jar last season.