Poor people living in difficult conditions can easily produce fresh food by gardening on sacks. It can be recommended to create tunnels with drought-tolerant Navajo willows to improve the gardening conditions (shadow, air humidity). More yield equals less poverty and less desertification.

1. SACK GARDENING AND NAVAJO WILLOWS TO COMBAT DESERTIFICATION AND
POVERTY
Prof. Dr. Willem VAN COTTHEM
Honorary Professor
University of Ghent, Belgium
The numerous advantages of sack gardening and growing drought-tolerant Navajo willows have
been described earlier:
(a) Sack gardening
Several articles describe the advantages of sack gardening, in particular for poor people with
limited space for food production.
http://desertification.wordpress.com/2011/02/05/farming-in-small-spaces-by-filling-tall-sacks-
with-soil-city-farmer-news/
http://desertification.wordpress.com/2011/08/28/sack-gardening-a-simple-technology-to-eat-
fresh-food-and-to-earn-a-living-irin-news-allafrica-c-odera/
http://desertification.wordpress.com/2011/08/29/the-popularity-of-sack-gardening-for-combating-
hunger-and-malnutrition-cynthia-odera-willem-van-cotthem/
Recently, I was discussing opportunities to grow fresh food in an arid environment with Nicol-
André BERDELLé (Germany). We suggested to combine both methods/techniques (sacks and
trees) in order to solve a number of well-known problems: drought, limited quantity of irrigation
water, heat, UV-radiation, etc, killing different birds with one stone.
Taking into account that, at the global level, urban population is continuously growing, and that
all these people lack some basic skills and resources, like agricultural or horticultural knowledge
and experience, land tenure, funds, etc., there is an urgent need for enhancing their food
production’s potential by teaching them very simple, but effective ways to grow food in small
spaces of the urban environment.
In January 2011, I have been reading at the blog of ‘NOURISHING THE PLANET’:
“In Kibera, the largest slum in sub-Saharan Africa, located in Nairobi, over 1,000, mainly female,
farmers now grow food quickly and in small spaces by filling tall sacks with soil and poking holes
on different levels to plant seeds. These “vertical gardens” helped Nairobi families survive when

2. unrest after the 2008 elections shut down roads and prevented food from coming into the cities.
Growing food for their families and selling the surplus also helps people improve their diets and
livelihoods. …………………………. And urban farmers are finding innovative ways of growing
food when they don’t have access to soil and other natural resources. With help from the
Education Concerns for Hunger Organization (ECHO) farmers are taking advantage of trash by
creating gardens from old tires, which they cut in half to use as gardening containers. Chapter
10 in State of the World 2011 explains how farmers can use old cans, plastic bags, and other
garbage, along with organic waste, to grow food in these planters, which can be used on
rooftops and moved around easily when space is tight. And these are just the beginning. Do
you know of any other innovative projects that are working to help urban farmers?
” (http://blogs.worldwatch.org/nourishingtheplanet/what-works-urban-agriculture-nourishing-the-
planet-solidarites-kibera-urban-harvest-iwmi-international-water-management-institute-echo-
africa-hunger-city-urbanization-food-food-security/)
A nice photo of Bernard POLLACK was added, showing how successful sack gardening can be.
In 2008, the Lebanese-born artist Mona HATOUM created in Berlin an artwork called “Hanging
Garden”, described as follows: “………..her 'hanging garden' consists of 770 jute sacks,
stacked to head level. All together, they form a 10 meter long wall,
which looks much like the sandbag barricades used as defense from enemy gunfire during
battle and other war zones such as checkpoints and border crossings. Despite the associations
we have with the image of these barricades, the sacks are filled with seeds that sprout, greening
the wall and expressing more of an image of growth and prosperity. The piece deals with the
friction between notions of home, security, warmth
and their opposites.”
Some photos have been published at:
http://www.designboom.com/weblog/cat/10/view/4365/hanging-garden-by-mona-hatoum.html
and at
http://www.lushe.com.au/tag/mona-hatoum/
(b) Navajo Willows

3. ‘Navajo’ is a very hardy tree, adapted to high desert climates. Unlike most willows, this variety is
popular in high desert and drylands because it is drought tolerant, adaptable to a wide range of
soil conditions.
It is a round-headed, fast-growing, deciduous, long lived tree, medium-sized, 20’ to 70′ tall and
wide. Its branching results in a characteristic globe shape: a broad, rounded crown. Its slender
leaves are bright green, lance-shaped, 2″-4″ long, turning yellow in fall.
The Navajo Globe Willow is related to the Corkscrew willow (Salix matsudana var. ‘Tortuosa’).
Back in 2010, we considered the use of this drought-tolerant tree species and asked ourselves :
“Will the Navajo willow become a star in reforestation of the drylands?’
https://desertification.wordpress.com/2010/03/16/will-the-navajo-willow-become-a-star-in-
reforestation-willem-van-cotthem/
Growing a number of Navajo Willow cuttings in small plastic bottles in 2010, we developed the
idea of the “bottle reforestation-method” for enhancing the survival rate of saplings :
https://desertification.wordpress.com/2010/03/15/reforestation-success-with-the-navajo-willow-
willem-van-cotthem/
We added to this the idea of creating tree tunnels with the Navajo willows :
https://desertification.wordpress.com/2013/04/09/combating-desertification-with-tree-tunnels-
avantgardens-willem-van-cotthem/
In 2011-2013 we further developed the idea of creating live greenhouses in all the drylands with
this interesting tree species : “No more plastic greenhouses or tunnels needed : grow your
own live greenhouse (a green teepee or a tunnel) with branches of the drought-tolerant
Navajo willow, also called globe willow or Chinese willow (Salix matsudana). One can
grow these willows with a minimum of water in the drylands, even in the desert. Such
a live greenhouse offers remarkable advantages : natural shade and higher air
humidity inside because of the transpiration by the leaves. In drylands or deserts
people can easily grow plants, e.g. young fruit trees and vegetables, inside such a
greenhouse, which can also offer shelter against the sun heat. Outgrowing branches of
the willow can easily be pruned to construct progressively new greenhouses. A very
interesting way to combat drought and desertification.“

4. We added : “ I deeply believe that it is possible to grow green teepees in all desert-like
areas where a minimal volume of irrigation water is available. This Navajo willow is
a drought-tolerant variety. It can develop and be propagated in extremely dry
environment. Growing tunnels with this willow would offer great opportunities for
food production inside the tunnels, in the shadow and surrounded by a higher relative
humidity. Moreover, lots of climbing, edible plants (peas, beans, passion fruit,
cucumber, dragon fruit, etc.) can be grown in the teepee wall.”
See also :
https://desertification.wordpress.com/2011/12/25/thousands-of-living-greenhouses-
to-combat-desertification-willem-van-cotthem/
and
https://desertification.wordpress.com/2012/03/07/building-living-tunnel-
greenhouses-for-rural-people-in-the-drylands-willem-van-cotthem-2/
(c) Combining sack gardening with Navajo willows
It goes without saying that growing fresh food (vegetables and herbs) on sacks can
advantageously become more productive when installing rows of sacks in live tunnels or
greenhouses created with the Navajo willow.
All these advantages have been described in the articles above.
We are wondering if experts working on development projects in the drylands are
interested in giving this combination a try.