One of my gardening goals for 2017 is to be able to eat something I grow fresh everyday. Yes, every single day of the year. Problem#1: it's winter and nothing is growing outside. I don't have a greenhouse and don't plan on building one, so I need to figure out how grow something indoor. Problem#2: Hydroponics could work, but I don't want to invest in setting up a costly, complicated system. I want something fast, cheap, practical. Something off-grid, combat-style.
I came across a few Youtube videos on a hydroponic method called Kratky, named after BA Kratky (University of Hawaii) who published this in 2009. The idea is simple, grow plants in static, non-circulating nutrient from beginning to end. No pump, no plug, no power. The key here is to allow the plant to have a pocket of air 'gap' between the root and the liquid. The nutrient is filled up high, and as the roots grow and reach down, the nutrient level retreats. By harvest time, there should be hardly any liquid left.
Important to note here is that I didn't invent this. People were already doing this successfully. See below for list of learning resources.
What you'll need:
(I wanted to do this as cheap as possible)
1. wide-mouth jars - I use pint, but probably should find larger sizes
2. 3-inch net cups,
3. peat pellets (Jiffy)
*note: don't use peat pellet in normal, circulating system.
4. clay pebbles
5. hydroponic lettuce nutrient powder (Urban Hydroponics). Other kinds would probably work fine as long as you use it according to manufacturer's instruction.
6. lettuce seeds
7. water
I got item 2,4,6 from Amazon, the rest I gathered from around the house. Overall this costed me around $25 in supplies, and will probably last through numerous growing cycles.
The steps:
I germinated lettuce seeds in hydrated Jiffy pellets like normal. I over-seeded, meaning there were too many seeds in each pellet -- way more than you'd normally do if you wanted a full-sized heads of lettuce. I wanted a bunch of smaller plants so I can continuously harvest individual leaves over a long period of time (cut and come again style). Within a few days, the seeds germinated, and I put them in as much light as my window can let in at this time of the year (late December).
Once the seedlings are about a week old, I popped the whole thing (pellet+plants) into the 3-inch net cup, and weighed it down with some pre-washed clay pebbles. *important - soak and rinse these pebbles well before use. In a separate container, I mixed the hydroponic nutrient powder with tap water and let it dissolve well. The ratio is 0.3 gram nutrient powder per 1 pint of water.
A note about the nutrient: as Gary (The Rusted Garden) mentioned in the seed-starting video, plants don't care and won't care if the nutrient you give them is organic or not. This stuff I use is not organic. In fact, it is the opposite of organic -- synthetic nutrients made by human. However, to plants, nitrogen is nitrogen. They have no way to sense if the nitrogen came from a broken down grass clipping or synthetic nitrate. In my outdoor summer garden, I am a hardcore organic gardener. I compost, and use all organic fertilizer. I build my soil with organic matter and healthy microorganisms, letting stuff break down over the season and nourish my plants over time. In hydroponic setup, none of that exists. Nutrients come in the form of chemical compounds that plants can readily absorb and utilize. To me, as a biologist and a gardener, as long as there's no heavy metal and it is intended to be used in hydroponics, it is safe to eat. In fact, I've already eaten a good amount of my hydroponic harvest and I'm still alive and well.
Back to the setup, Once the plants were situated in the net cup, I dropped the whole thing into a mason jar (it should fit snuggly) and filled it with the aforementioned nutrient solution up to just covering the lower part of the Jiffy pellet, making sure the pellet stayed moist. I set this near a bright window and let it grow.
Here's where I deviated from the book. In standard Kratky method, you're not supposed to fill the water until harvest time. However, I've noticed that my plants are using the water much, much more quickly, maybe because there's simply too many plants and the water evaporated through the space between the clay pebbles. So I decided to replenish the container with water (plain water, no nutrient). My rationale here is that this will bring the concentration of whatever nutrient is in the jar back to the original level.
Two weeks later, I noticed that some of the leaves started to turn pale green, almost white. This is a sign of nutrient deficiency. The overly crowded plants were using the nutrients so quickly they'd run out of it. One problem here though, I had no way to tell what nutrient ran out first (i.e. think limiting reagent, my chemist friends out there). I suspect nitrogen was probably the first to go, since leafy greens are heavy nitrogen feeder. Regardless, I decided to just change out the whole thing and filled it back to the same level with the same original (but newly mixed) nutrient. The plants started to grow new green leaves again almost immediately.
A note about root: some people wrap their jars with paper or foil, or use non-opaque containers that don't let any light through. The main reason is to inhibit growth of algae (they use the same nutrient as plants, and need light). Algae are (usually) harmless, they just look green and yucky, so people don't like to look at them. As far as plant roots are concerned, they don't care if you expose them to light. Plant roots (most, anyway) don't perform any photosynthesis whatsoever, so exposing them to light won't do any good (or harm). I just left my jars open so I could see what was going on inside, observe the root growth and monitor the nutrient level. And, since I swap the nutrient solution and clean out the jars every few weeks, algae have no chance to grow anyway.
I started picking the leaves to add to salad at 3 week, and am still picking now (about 4 weeks later). We'll see how long these little guys can continue to produce.
Variables I still need to work out:
Nutrient changing regime
Seedling density - what's the maximum amount of food I can grow in a given space
Jar size and cost/ benefit
Try other kinds of plants - I am experimenting with arugula and basil now
(leafy greens seem to work best with this method. For tomato, pepper, or other fruiting plants, you'll need a full-fledged hydroponic system)
Online Resources:
Beautiful lettuce by frugalgreengirl: https://youtu.be/TXLYUjEbmog
This is the setup I modeled mine after, except I use Jiffy pellets instead of rockwool
Will it Kratky: https://youtu.be/BNiQNHDaxrE
Cheap Kratky setup by Khang Starr: https://youtu.be/uqUn5N9U3IQ
Outdoor Kratky (also by Khang): https://youtu.be/LQQlHnQ7fPU
Kratky on Instructable: http://www.instructables.com/id/Kratkys-non-circulating-hydroponics/
Disclaimer: I wrote this for my own personal record and to collect my thoughts. Please feel free to read, like, comment, share as you see fit. But this is by no mean authoritative (i.e. don't sue me if you screwed up your garden). Also, I don't work for and am not paid by anyone mentioned above.
I came across a few Youtube videos on a hydroponic method called Kratky, named after BA Kratky (University of Hawaii) who published this in 2009. The idea is simple, grow plants in static, non-circulating nutrient from beginning to end. No pump, no plug, no power. The key here is to allow the plant to have a pocket of air 'gap' between the root and the liquid. The nutrient is filled up high, and as the roots grow and reach down, the nutrient level retreats. By harvest time, there should be hardly any liquid left.
Important to note here is that I didn't invent this. People were already doing this successfully. See below for list of learning resources.
What you'll need:
(I wanted to do this as cheap as possible)
1. wide-mouth jars - I use pint, but probably should find larger sizes
2. 3-inch net cups,
3. peat pellets (Jiffy)
*note: don't use peat pellet in normal, circulating system.
4. clay pebbles
5. hydroponic lettuce nutrient powder (Urban Hydroponics). Other kinds would probably work fine as long as you use it according to manufacturer's instruction.
6. lettuce seeds
7. water
I got item 2,4,6 from Amazon, the rest I gathered from around the house. Overall this costed me around $25 in supplies, and will probably last through numerous growing cycles.
The steps:
I germinated lettuce seeds in hydrated Jiffy pellets like normal. I over-seeded, meaning there were too many seeds in each pellet -- way more than you'd normally do if you wanted a full-sized heads of lettuce. I wanted a bunch of smaller plants so I can continuously harvest individual leaves over a long period of time (cut and come again style). Within a few days, the seeds germinated, and I put them in as much light as my window can let in at this time of the year (late December).
Once the seedlings are about a week old, I popped the whole thing (pellet+plants) into the 3-inch net cup, and weighed it down with some pre-washed clay pebbles. *important - soak and rinse these pebbles well before use. In a separate container, I mixed the hydroponic nutrient powder with tap water and let it dissolve well. The ratio is 0.3 gram nutrient powder per 1 pint of water.
A note about the nutrient: as Gary (The Rusted Garden) mentioned in the seed-starting video, plants don't care and won't care if the nutrient you give them is organic or not. This stuff I use is not organic. In fact, it is the opposite of organic -- synthetic nutrients made by human. However, to plants, nitrogen is nitrogen. They have no way to sense if the nitrogen came from a broken down grass clipping or synthetic nitrate. In my outdoor summer garden, I am a hardcore organic gardener. I compost, and use all organic fertilizer. I build my soil with organic matter and healthy microorganisms, letting stuff break down over the season and nourish my plants over time. In hydroponic setup, none of that exists. Nutrients come in the form of chemical compounds that plants can readily absorb and utilize. To me, as a biologist and a gardener, as long as there's no heavy metal and it is intended to be used in hydroponics, it is safe to eat. In fact, I've already eaten a good amount of my hydroponic harvest and I'm still alive and well.
Back to the setup, Once the plants were situated in the net cup, I dropped the whole thing into a mason jar (it should fit snuggly) and filled it with the aforementioned nutrient solution up to just covering the lower part of the Jiffy pellet, making sure the pellet stayed moist. I set this near a bright window and let it grow.
Here's where I deviated from the book. In standard Kratky method, you're not supposed to fill the water until harvest time. However, I've noticed that my plants are using the water much, much more quickly, maybe because there's simply too many plants and the water evaporated through the space between the clay pebbles. So I decided to replenish the container with water (plain water, no nutrient). My rationale here is that this will bring the concentration of whatever nutrient is in the jar back to the original level.
Two weeks later, I noticed that some of the leaves started to turn pale green, almost white. This is a sign of nutrient deficiency. The overly crowded plants were using the nutrients so quickly they'd run out of it. One problem here though, I had no way to tell what nutrient ran out first (i.e. think limiting reagent, my chemist friends out there). I suspect nitrogen was probably the first to go, since leafy greens are heavy nitrogen feeder. Regardless, I decided to just change out the whole thing and filled it back to the same level with the same original (but newly mixed) nutrient. The plants started to grow new green leaves again almost immediately.
A note about root: some people wrap their jars with paper or foil, or use non-opaque containers that don't let any light through. The main reason is to inhibit growth of algae (they use the same nutrient as plants, and need light). Algae are (usually) harmless, they just look green and yucky, so people don't like to look at them. As far as plant roots are concerned, they don't care if you expose them to light. Plant roots (most, anyway) don't perform any photosynthesis whatsoever, so exposing them to light won't do any good (or harm). I just left my jars open so I could see what was going on inside, observe the root growth and monitor the nutrient level. And, since I swap the nutrient solution and clean out the jars every few weeks, algae have no chance to grow anyway.
I started picking the leaves to add to salad at 3 week, and am still picking now (about 4 weeks later). We'll see how long these little guys can continue to produce.
Variables I still need to work out:
Nutrient changing regime
Seedling density - what's the maximum amount of food I can grow in a given space
Jar size and cost/ benefit
Try other kinds of plants - I am experimenting with arugula and basil now
(leafy greens seem to work best with this method. For tomato, pepper, or other fruiting plants, you'll need a full-fledged hydroponic system)
Online Resources:
Beautiful lettuce by frugalgreengirl: https://youtu.be/TXLYUjEbmog
This is the setup I modeled mine after, except I use Jiffy pellets instead of rockwool
Will it Kratky: https://youtu.be/BNiQNHDaxrE
Cheap Kratky setup by Khang Starr: https://youtu.be/uqUn5N9U3IQ
Outdoor Kratky (also by Khang): https://youtu.be/LQQlHnQ7fPU
Kratky on Instructable: http://www.instructables.com/id/Kratkys-non-circulating-hydroponics/
Disclaimer: I wrote this for my own personal record and to collect my thoughts. Please feel free to read, like, comment, share as you see fit. But this is by no mean authoritative (i.e. don't sue me if you screwed up your garden). Also, I don't work for and am not paid by anyone mentioned above.
3 comments:
Thank you for sharing your experience. I was thinking about the adding water part too, most videos show you don't need to add water or change. I feel that one should or may have to add or change water/solution.
thanks again for sharing.
mobile grow system help buiding hydroponic system.
Nice job.
I use the kratke system using jars. I built some miniature green houses (3' X 4') so I could put the jars outside. an expert on this said real sun is better than grow lights due to the full spectrum it provides.
I have to hand it to you, especially with the lettuce. I may just try your indoor method year around. My lettuce plants barely became microgreens outside. So I'll try your method.
I like to start my tomato, cucumber and pepper seeds with kratke. The seedlings, for whatever reason, are far superior than ones bought at the nursery or with other soil methods. Maybe the constant nutrient intake makes a difference. My transplanted Purple Cherokees are 5.5' tall, and it's only June. I have new peppers and cukes everyday. I never had that kind of success or bounty with traditional seed starting. Just an idea.
By the way, herbs do extremely well with kratke jars. I grow basil, greek oregano, thyme and rosemary very successfully. The oregano and thyme do better with multiple seeds and germinate quickly. I also use 3 seeds for rosemary, then transplant into soil when they reach about 3". My first kratke rosemary is a 3' tall container bush.
Thanks for the post.
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