Garbage Gardening

We learned from our Peace Corp friend, Curt Lindley, that materials that we take for granted here in the USA are often very hard to find and expensive in developing nations. Try to find inexpensive sphagnum peat, vermiculite or perlite in downtown New Dehli.

Therefore, we've begun to experiment with garbage and other free materials that could replace the potting mix in our traditional Global Bucket. We're testing plastic bottles, newspapers, cardboard, old books, discarded clothing, Coke cans and sticks.

How could cloth or newspapers replace potting mix? Well, a plant's roots only require three essential items:
1) water
2) air
3) nutrients

Based on our testing, we've discovered that rolled-up newspapers and t-shirts, for example, are excellent at wicking water from the bottom of the bucket up to the top of the bucket where the plant's root ball will be located. Will the newspapers disintegrate too quickly? Perhaps, but maybe the plant's water seeking roots will reach the bottom water reservoir before the wicking newspapers fall apart.

By placing a bundle of sticks or a cut-up plastic bottles or Coke cans between the rolled-up newspapers or t-shirts we believe the aeration requirement will be met.

We'll be trying two different approaches. The first approach is to sprinkle some timed-released fertilizer (eg Osmocote) and dolomite in the newspapers/t-shirts as they are rolled-up. The second idea to to use liquid fertilizer in the water along with some dolomite sprinkled in the newspapers/t-shirts.

Will it work? We have no idea!

We'll be testing our new "worthless" system during the summer of 2010.

Click the photos for larger images.

Some materials to be tested: (pictured left to right):
1) Burlap or Hessian Cloth (coarse woven cloth made from jute)
2) Swamp cooler material (not practical, but we were curious)
2) T-shirt (with sticks to provide aeration)
3) T-shirt (with cut-up 1 L bottle to provide aeration)
4) Polyester (micro-fibers)

The wicking test results:
1) Burlap : D (maybe because "fancy" colored USA cloth burlap)
2) Swamp cooler material : F
2) T-shirt (with sticks to provide aeration) : A
3) T-shirt (with cut-up 1 L bottle to provide aeration): A
4) Polyester (micro-fiber): F (maybe because very loose fibers)

T-shirts wrapped around cut-up 1 L bottles...looks very promising.

Testing newspaers as wicks. Results: Excellent Wicking!

Below is a picture of our first Garbage Bucket. Newspapers have been crumpled-up into balls and tightly packed between plastic 1 liter bottles. We sliced the bottles with four vertical cuts from top to bottom. Then we stepped on the bottles to flatten them somewhat. The bottles provide a very airy mass, but are strong enough to stand vertically and provide support to the newspapers. We sprinkled dolomite (1 tablespoon ("Tbsp") (equals 15 milliliters) ) and a basic 10-10-10 fertilizer with micro-nutrients (2 Tbsp) at three different lawyers. We didn't use rolled-up newspapers like in the above picture, because we didn't see a good way to place the fertilizer and dolomite.

The questions we have are:
1) Will the fertilizer be dispersed enough so the plant's roots won't burn?
2) Will the wet newspapers "melt" into one big glob so the roots won't be able to get to the airy

5-21-10: Filling up the bucket. (click on image)

That's 10-10-10 fertilizer and dolomite on the newspapers.

Fully packed. The 1 liter bottles are buried vertically.

5-22-10 Update: After 24 hours, water had wicked-up from the bottom reservoir (1 gallon) up to the second from top layer of newspapers.

5-23-10 Update: After 36 hours, the top newspapers were moist. Below the top layer, the newspapers were very moist. We wonder if this would provide enough water for a tomato plant.

6-1-10 Update: Planting our first newspaper bucket.

We'll be irrigating using the PVC tube into the reservoir, but we directly watered the plant when we first planted it.

Planting a tomato in newspapers. The "dirt" potting mix is from the container that the seedling came in.

Our Garbage Garden.

We're using white plastic, rather than black plastic, because we've come to realize that Boulder Colorado is one of the sunniest places in the USA. Last year we used black plastic, but it created extreme soil temperatures.

Update 7-18-10:  The results of the newspaper and cloth "potting mix" have been disappointing.  The plants are still alive, but they are not thriving.  The plants in our other summer 2010 experiments, ollas combined with Global Buckets and Grow Bags are doing excellent.

Update September 5, 2010:  The final results of the Garbage Garden were disappointing.  In fact, we're too embarrassed to print photos of these still living, but sad looking, pathetic plants.  We believe the idea can still work, but we need to re-engineer our system.  Check back during the summer of 2011 for some new ideas.

Update 10-26-10:  Larry Kurtz from Omaha, Nebraska wrote to us with a brilliant idea:
I think you gave up too early on newspaper. You're trying to provide a
rooting medium for the plants.  I'm assuming that there's too much air and
not enough "root to cellulose contact" to effectively feed the plants.
Shredding the newspaper to finer particles should provide more nutrients to
the plants.  My interest in newspaper is the repurposing of a recyclable
that doesn't have the "green" downside of either peat (sustainability) or
coir (carbon footprint of delivery...salt problems, etc.).

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OLD : Olla Irrigation (Clay Pot System)

We've been inspired by Fan Sheng-chih Shu. His writings from the first century BC describe a method of irrigation where a unglazed clay pot is buried in the soil. When filled with water the clay pot turns into an amazing high-tech device. The micro-pores of the clay pot allows water to seep into the surrounding soil. A key characteristic is that the water seepage is regulated by the water needs of any nearby plant. When the plant's water demands have been fulfilled and the soil is moist, the water seepage from the clay pot will stop. When the soil becomes dry, water seepage will begin again. This seepage is controlled by soil moisture tension. It's automatic irrigation without timers or electronic sensors!

Water Efficiency Combined with Liquid Fertilizer
Some designs (see below) allow you to bury the olla in the soil or potting mix. This allows the delivery of water directly to the plant's roots. No water is wasted. This is excellent for arid climates like in many parts of Africa. Finally, you may supply the olla with water mixed with liquid fertilizer. You'll only need about 1/4 to 1/2 of the fertilizer you would normally use. Although liquid fertilizer is more expensive than granular, it may end up costing less because of the tremendous efficiency of the delivery of the fertilizer directly to the plant's roots.

Combining Ollas with Global Buckets
Only one bucket is required and the use of power tools for drilling and cutting of buckets is eliminated. It's much more fun to caulk (required for clay pots) than to drill. We've begun (summer 2010) the testing of ollas in Global Buckets. So far we've had excellent results.

How to build your own Olla Global Bucket system:
Step 1: Build the clay pot. It's easy! Just glue two unglazed flower pots together.
Step 2: Bury your clay pot into a bucket with just the top of the clay pot exposed. Use potting mix with dolomite.
Step 3: Keep the clay pot filled with water. After a month of hand watering (boring!), we're designing an automatic watering system (see below).

Step 1: Build an Olla
Seal the hole in what will become the bottom section of the clay pot. We bought a ceramic floor tile from Home Depot for 99 cents and broke it up into little pieces. Apply lots of waterproof silicon caulk around the opening and then stick a piece of the broken floor tile over the hole. We also caulked the other side (pot's exterior) of this hole with more silicon caulk just to ensure that leakage won't be a problem.

Next you'll need to attach the two clay pots together.

If you're using Gorilla Glue (as we do) you'll need to lightly wet one of the pots as shown in this picture.

We first use 100% waterproof Gorilla Glue. We let the Gorilla Glue dry overnight. We then put heavy amounts of silicon caulk over the connection (the Gorilla Glue leaves lots of tiny gaps). The end result is not very pretty, but it's watertight!

The finished product. We painted the top of the Ollas that will be exposed to sunlight with white paint. Since the top is now painted or glazed, evaporation will be greatly reduced. We learned this the hard way.

If you click on these pictures to enlarge them, you'll see where the potting mix is moist from the olla.

Ollas (Clay Pots) in Developing Nations
This is an excellent Phd thesis from a student at the University of Pretoria on the use of clay pots in developing nations. Lots of great information.

This research paper is from the OAS (Organization of American States). It also relates to clay pot's use in developing nations.

Automated Olla Irrigation
(Note: We're still testing this design. No guarantees of success.)

Newest Design : 6-29-10 : Still Testing.....
The goal of this design is simplicity, leak-free smaller ollas and gravity feed (no siphons).

a) 1/4" poly pipe
b) 1/4" "T"
c) 1/4" x 1 1/4" Fender Washer
d) Silicon Caulk
e) Plumbing Epoxy Putty (it's waterproof, easy to handle and safe for humans)
f) Terra Cotta Pot and Saucer

We used plumbing epoxy putty for everything, except when we used silicon caulk to attach and seal the saucer to the pot. We used two brands of plumbing epoxy putty. In the pictures, one brand is white and the other is gray.
That's white silicon caulk between the pot and saucer.

This week we'll attach a series of these ollas to a gravity fed 55-gallon barrel for the final testing.

1st Attempt at Automated Olla Irrigation
Result : Leaks!
There appears to be some water leaking where the 1/4" poly pipe enters the 7/32" holes. We're beginning to believe that the silicon caulk doesn't adhere 100% to the slick poly pipe. We are looking into alternatives.

We've modified most of our clay pots to implement our automatic clay pot water refilling system.

Step 1: Drill two holes in what will become the top section of the clay pot. Do this before you glue the two pots together. Use a 7/32" concrete drill bit. Later you'll be inserting 1/4" irrigation tubing into these two holes.

Step 2: You will also need to seal the the top drain hole that exists in the original pot. Do this before you glue the two pots together. Seal it like we sealed the bottom hole (ie silicon caulk and broken floor tile).

Because we modified our top pot after they were glued together (not recommended) they're really ugly!

A 4" clay pot is buried. One 1/4" tube is the water feed. The second 1/4" tube allows air to flow out when the pot is filling with water. Once the clay pot is filled with water, water travels through this second tube to the next clay pot in the series.

The 4" olla is completely buried.

This is a 6" olla. It takes up a large amount of space. We were unable to completely bury it.

This post will be updated throughout the summer of 2010 as we implement the olla system in Global Buckets.

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