Article 6-1 Growing Your Own Food In a Tub

In 1969 I was a 20 year old impoverished college student. I was living on a rundown houseboat in the Willamette slough in Portland Oregon. After a few months of trying to live on fast-food at the University, I realized I needed to reduce the $300 per month I was spending on food.

My houseboat had a large back deck that had a clear plastic roof to protect against Portland’s infamous drenching rains. It was on the south side of the house and had plenty of sun year round, or at least plenty of light.

Being a hippie revolutionary type in those days, I scrounged through second-hand stores for clothes and other things and found a handbook on survival. In that book there was mention of a hydroponic system that could grow $450 worth of food a year with only $5 in nutrients. I figured I had found my solution for food.

The article told me nothing about how to do it. So I went to a large used bookstore in Portland and found one lonely, rather small book entitled “The Complete guide to Soilless Gardening” by W. F. Gericke. Written in 1940, already 29 years old, it contained hard to see photos and musty pages. But I looked through it and it showed how to build containers, what fertilizers to mix for nutrients and best of all a picture showing a grower filled with potatoes.

I bought the book, never imaging it would be the best investment I would ever make, and it changed my life.

Back home I carefully studied Gericke’s hydroponic trough growers. He usually dug holes in the ground, waterproofed them, added water with nutrients and then placed a top made of chicken wire, filled with excelsior and containing plants.

The secret of success in Gericke’s early systems was to have a layer of air between the water and excelsior. This air layer had vents to the outside, yet was dark and moist. It was here the roots grew the most.

I set up my first hydroponics grower on my deck. I used a beat up 10 gallon plastic storage tub, then placed a wood tray over that, and used moss from the woods outside my houseboat. When I asked at a few garden stores no one even knew what excelsior was. Finally a forestry student explained it was a material made of wood products, processed to be porous like a wood sponge. Gericke had mentioned sawdust as a substrate so I tried that instead. No garden store carries any hydroponic nutrients, but one recommended an all purpose fertilizer for soil. I bought that.

I planted a small tomato plant in my first grower and it quickly died. It seemed to make no effort to live at all, and I had no idea what was wrong. Looking through Gericke’s designs I realized I did not have any air holes between the water and the sawdust layer. Perhaps this was the problem. So I cut eight holes; two in each side that were about an inch in diameter. Then I bought another tomato plant.

Tomato number two lived a few more days than the first, but its death was also pretty rapid. So I went back to my book again and figured out the problem was either the nutrient I was using, the sawdust substrate and perhaps both.

I had no idea what sawdust I was using or if it would work, so I decided to try another substrate. Gericke mentioned gravel and we had a lot of that around the houseboat but I wanted to try something else. At the garden store I purchased a bag of perlite and vermiculite. I also bought two more tubs, 10 gallons Rubbermaid. My first tub was clear and it was growing algae in the water basin. I needed something darker that would block the sunlight, not allowing the algae to grow.

In the three tubs I used perlite in one, vermiculite in the second and sawdust in the third. I bought six lettuce seedlings and planted two in each grower. The vermiculite and the perlite worked better than the sawdust. All the lettuce sort of sat there growing very slowly. Eventually the two in the sawdust died, but the other four still tried to survive. They were very yellow, especially the older leaves. Gericke’s book mentioned this was probably a nitrogen deficiency.

Now I tackled the more frightening problem; looking at the nutrient or fertilizer I was using. Gericke explained that plants need 11 nutrients from the water (We now accept that 13 are needed). I looked at the fertilizer I bought at the garden store and suddenly realized why my plants were dying.

My fertilizer only had three basic nutrients; nitrogen, phosphorus and potassium otherwise known as NPK. The other minerals were missing. I did not know how much nutrient to add to the water and my teaspoon per 10 gallons of water was just a guess.

Being 1969, the hydroponic industry did not yet exist. I had six possible recipes in Gericke’s book, all using a mix of special 100% soluble fertilizers. It included ingredients like monopotassium phosphate, copper sulfate and about eight necessary ingredients. (see Table 1.)

Any of the three mixed together would supply the major nutrients the plants required. Then there were also five minor nutrients; iron sulfate, manganese sulfate, borax, zinc sulfate and copper sulfate. There would be more research before molybdenum and chlorine were known to be required for plants.

This was commitment time. Having no knowledge of where to get these things or any pre- made fertilizers, I had to decide if I was ready to make any further investment. I spent $11 on the book, about $20 in tubs, fertilizers, plants and substrate and all I had to show for my money were four very sad looking lettuce plants.

I was in a chemistry class at the time. Even though there were 200 students in my class, I took a chance and went to my professor’s office hour with my Gericke book, along with my notes and the list of chemicals I would need.

My professor looked at me and leaned back in his chair highly amused. He looked through the list a few times and made notes. Then he handed it back to me and explained.

“This magnesium sulfate you need is also called Epsom salts. You can buy it at a drug store because people use it to soak their feet. He reached up to his shelf and brought down a bottle from a health food store; a mineral supplement.” He read the back label awhile and showed it to me.

“You see these chelates, copper, zinc, iron, manganese? They should give you these trace minerals the plants need. Two in each tub of water each week should be enough.” He then looked at me through his half glasses and added; “You should know enough chemistry to make the calculations of how much you need. That leaves these last two, calcium nitrate and mono potassium phosphate.” He made a few telephone calls and then wrote down an address.

My University, Portland State, had no agricultural classes but my professor had located both fertilizers on campus. They were in the office of the groundskeeper. When I found the place, the man gave me a pint of each fertilizer clearly labeled. I went to a drug store, found Epsom salts and went home.

Armed with the necessary ingredients, I sat down at my houseboat table and tried to figure out how much I would need for each of my 10 gallon tanks. I weighed out the necessary amounts following Gericke�s instructions and made a mixture. Then I dumped out the fertilizer water I used before, cleaned the tanks and filled each with new water and my mixture.

The next day I thought I saw a difference. I could see the new dark green lettuce in the center of each plant. By the end of the week it was clear the lettuce was growing.

That was the beginning. In three weeks I had lettuce for a salad and in three months I had 16 tubs, and everyday I would go out and pick tomatoes, cucumber, green beans, onions, carrots, lettuce and other vegetables. Those 16 tubs, 32 square feet, gave me about 2/3 of a pound of food every day: 1/3 pound of lettuce and tomato and 1/3 pound of other vegetables. I cooked a curry every day with rice and tofu and my monthly food bill dropped from $300 per month to about $30. I think it helped my seizure disorder also. I felt in better health.

I still eat my meals from my hydroponic garden 34 years later. Some things have changed. Now all the tubs are completely filled with horticultural grade perlite. There is a perlite that is like dust for mixing with cement and a horticultural grade perlite of small pieces, measuring from two to nine millimeters. The tubs all have one drain hole about one inch from the bottom so they retain an inch of water in the bottom of the tub. Every day I hand water them all with a watering can and every day at lunchtime I pick the foods I need for lunch.

I still use a hydroponic nutrient that I make myself, based on research over the past 30 years. I have a Grow Root and Bloom nutrient that I manufacture and sell worldwide.

A garden like mine can be set up in an afternoon. Sixteen tubs are fashioned into growers by cutting holes and fixing drains. The tubs are filled with perlite, and then nutrient water is mixed and poured. Plants either can be transplanted into the growers or seeds can be started in the growers. Very small seeds like herbs may wash out of the grower before seeds can germinate. Most cuttings will survive if started on root nutrient.

Almost all the modern hydroponic nutrients will work for the hydroponic home garden. It is much easier now to get started in hydroponics than was true when I took it up.

I sell a kit to begin a garden. It has a book, “Home Hydroponic Gardens” and the necessary nutrients to get started. The kit is available in English, Spanish and French.

Peggy Bradley has been a hydroponic grower for over 30 years. She is now the Executive Director of International Institute of Simplified Hydroponics based in Tehuacan Mexico and working to end hunger worldwide.


Gericke, W. F., 1949, The Complete Guide to Soilless Gardening, Prentice-Hall, New York.