Introduction
Sack gardening is a form container
gardening that can be practised in densely populated areas where a
garden plot is usually not available for most parts of the local
population. Like other forms of urban gardens that can be found
worldwide since the existence of cities, i.e. roof, backyard or
community gardens, they all complement the nutrition of their owners by
providing vegetables, herbs and staples (Marsh, 1998). From that
perspective sack gardens doesn’t represent a traditional gardening
system as its application is more beneficial to slum population or to
people that life in other forms of densely populated environments such
as camps, where arable land is scarce (Forbes, 2009) and access to the
inputs for agricultural production is limited or non-existent, for
example due to the lack of cash (Pascal, Mwende, 2009). Additional
factors such as rising world market prices and violence intensify the
vulnerability of the urban poor population further by limiting their
access to food which results in malnutrition and increasing
vulnerability to diseases. Therefore, the objective of sack gardening
is to increase the access to food, thus increasing the food security
and to provide means of gaining an income by selling possible surplus
food (Pascal, Mwende, 2009).
Sack gardening as a form of
container gardening has no long tradition, at least no literature was
found which mentioned the usage of sack gardens in ancient times, and
is recently applied only in development projects for the improvement of
food access for the food insecure in cities and displacement camps
(Solidarités, 2009 and Forbes, 2009). Therefore, gardens in sacks
address those people that normally won’t benefit from development
projects that try to improve the nutrition of the community and which
are often criticised because they exclude by the default all people
with limited or no access to land at all (Marsh, 1998). Further
criticism states in general that garden projects often fail because
local or traditional knowledge, local climatic and environmental
conditions as well as social and resource supply conditions are not
taken into account (Brownrigg, 1985 cited in Marsh, 1998). It is
therefore important not to consider sack gardening, only because it is
relatively easy to set up, as a convenient way to improve food access
of the people. Every community possess is own local and traditional
knowledge about crops, climate, etc. That holds also true for
communities in cities or camps as they often come from a rural
background possessing their own knowledge about agriculture. That
specific local knowledge must be taken into account when setting up a
sack garden in a specific community transforming sack gardening into a
local technology. In general it seems to be consensus that local and
traditional knowledge of the community or an individual family must
always be taken into account when implementing development projects
that address nutrition issues (Marsh, 1998).
"It is essential to
build on the indigenous gardening skills within the family, especially
with regard to cultivation and use of native and wild plants,
experience with mixed cropping and intercropping and traditional
methods of conserving water and combating pests." (Marsh, 1998)
Preparation
Sack
gardens usually make use of top and lateral areas of the sack. Theses
faces of the sack provide more arable area on the small space necessary
to place the sack. According to Pascal and Mwende (2009), seeds cannot
be planted directly into earth of the sack but must mature on small
plots before they can be replanted into it. The mature period takes in
general around three weeks depending on the type of vegetable chosen.
According
to Pascal and Mwende (2009), the size of a sack varies between 0.1m3
and 0.5m3 with different types of vegetables population planted on the
top and the side through small holes. The sacks can be prepared in
different ways in order to guarantee that plants in the lower areas
receive enough irrigation water as shown in the following variants.
Stone Spine
A
vertical stone spine placed through the soil from the top to the bottom
of the sack, made of 20-40mm stones, in order to allow irrigation in
the lower soil areas of the sack. The spine is created by a pipe or box
made of plastic, metal or cardboard (Forbes, 2009) which is filled with
stones after the soil has been removed from their interior. Radice
(2005) mentions the use of banana stems in Uganda. The stem is placed
in the sack first and filled with stones. Then the sack gets then
filled with loamy soil and the stems removed leaving a stone spine for
irrigation purposes. When the sack gets irrigated, water is filled in
the stone spine which let it slowly flow through from the top to the
bottom while gradually irrigating the plants. This setup has the
advantage that it is easy to construct and still provides the complete
lateral surface area for cultivation.
(Stone Spine schematic, Solidarités, 2009) 
Stone Layers
Horizontal layers of stone are introduced at the top, in the middle and at the
bottom of the sack dividing it in two sectors of soil. The layers are
connected with a pole made of any suitable material in order to
guarantee irrigation in each sector.
Disadvantageous in this setup is
the reduced cultivation area. The top of the sack cannot be used
anymore as it is covered with stones. The height of each stone layer
additionally reduced the lateral surface area available for cultivation.
(Stone Layer schematic; Solidarités, 2009)
Organic Material Layers
Doshi
and Shah (2003) suggest their own setup for sack gardens. Based on
their experiences made in India, high density polyethylene bags used
for packing cement or fertilizer are serving as containers. The size of
the bags varies according to the vegetables intended to plant. Only the
top of the sack is used as planting area while the lateral surface are
not suitable in this setup. This comes due to the fact that the sack is
open at the top and bottom, allowing water easily to drain out which
implies a certain layering structure of soil and biomass.
In order to prevent the soil from trickle through the bottom, the following layering structure is suggested:
(Organic Layer schematic; Joshi et al, 2003)
- the
bottom half of the sack (the lower 50%) needs to be filled with biomass
which serves as a plug for the upper layers and prevents them from
falling through the open bottom. The used biomass can be sugarcane
residues or any other freely available biomass residues. This layer is
supposed to be sufficiently porous in order to let water to drain out
half of the remaining space (25% of the bags height) is filled with
compost. Doshi and Shah (2003) suggest to produce own compost by
putting organic kitchen waste or dung from livestock and water into a
polyethylene sacks and leaving them for six weeks until the breakdown
of the used materials into compost is finished. The sacks are normally
closed which has the advantage that offensive smell is minimized and
insects and animals, like vermin, cockroaches and rats are not attracted - the
upper 25% of the sack are filled with normal soil. This layer is
eventually used for planting in order to finalize the sack setup, it
must be soaked with water for 2 or 3 times and the water must be
allowed to dry. Necessary sack sizes and diameters are determined by
the vegetable to be planted:- the general setup facilitates sacks with a length and diameter of around 22.5cm
- sugarcane crops need larger sacks with a diameter of around 35cm
- fruit trees like fig, mango and guava need sacks with a diameter ranging from 45cm to 52.5cm
- Finally,
seeds are usually placed 1.5cm to 2cm below the surface of the upper
soil layer. After an average of 3 weeks they are fully rooted and
emerge from the soil.
Using sacks for gardening exhibits the following advantages:
- Less
water usage then conventional farming due to the fact that the bags are
sealed and less water can evaporate or flow through the sack. - The
“Organic-Material” sacks requires less soil due to layering. The
materials for the non-soil layers can be self produced or are often
available for free. - The “Organic-Material” sacks are more leightweight and therefore more suitable for placing on rooftops or hanging on walls.
- Sacks are being easily and quickly constructed.
Disadvantages can be addresses as
- “Compost Layer” bags doesn’t facilitate the lateral surfaces due to layer structure, which results in less growing space.
- “Stone Layer” bags have a reduced cultivation are due to different layers of stones.
Maintenance and Monitoring
Forbes
(2005) reports that weekly maintenance time for the individual sack
gardens is marginal. 2 hours per week shall be necessary for watering,
weeding, replanting and fencing (were applicable in terms of space and
available resources). In addition to maintenance, constant and
frequent, i.e. weekly, monitoring shall be conducted in order to help
troubleshooting if necessary (Radice, 2005) but also to spread
informations about positive outcomes from which the other farmers could
benefit as well.
Community participation
Community involvement is
a key aspect of sack gardening projects and in general for all such
projects. The flow of information within in the project shall be
bi-directional in order to transparently propagate existing knowledge
and experiences to all participating parties (Marsh, 1998), the garden
instructors, the members and boards of the community, the benefiting
families, external institutions and so on.
Sack gardening in densely
populated areas does especially involve the whole community as existing
land is very scarce. That scarce land is collective land and can be
used to build small nursery beds which are needed for maturing the
seeds (Pascal, Mwende, 2009). Once the mature period for growing the
seeds is over, the seedlings are distributed to the community for free
and are replanted in the sacks (Pascal, Mwende, 2009). The collective
land can also be used for a training garden which can host training
sessions for the community and potential new gardeners (Radice, 2005).
It must therefore be the consensus of the community that scare areas
can be used for the preparation of sack gardening or teaching purposes.
(Nurser beds; Solidarités, 2009)
According to Pascal and Mwende (2009), members of the involved
community should be selected for monitoring and mobilisation. In order
to increase acceptance for the sack gardens in all layers of the
community, these individuals shall represent a good average in terms of
age, gender, knowledge background and profession. The selection can be
carried out by the elders or by consensus. Due to the fact that sack
gardening is a relatively unusual approach for conducting gardening and
people are used to know other ways of farming it may be initially
considered as "childish" or "strange" as reported by Radice (2005) but
may be considered worth a try once people are informed about its usage
and benefits. Frequent training is crucial to spread informations and
knowledge, not only about ways and methods of sack construction and
maintenance but also in order to raise awareness about nutrition
(Marsh, 1998) which is an important aspect of every gardening project
in general. Indigenous knowledge about locally occurring plants and
other social and environmental factors are important for gardening and
acceptance and must always be taken into account in order to avoid the
usually errors done in development projects (Marsh, 1998) by neglecting
the available knowledge within the community and trying instead to
import concepts not suitable for the region, i,e. the introduction of
foreign vegetable species not suitable for the local climate or not
accepted by the local community.
Further on, households are
responsible for the preparation of their sacks and depending on their
composition. The sacks itself, soil and stones may be obtained
individually by the community members. In cases where the necessary
resources, for example good soil, are not available, the community
members may have to buy them which may exclude certain household where
money is scarce (Pascal, Mwende, 2009). Other approaches prefer to
provide all input resources from sacks to seeds for free (Radice,
2005). A possible solution for the lack of inital money needed to
invest in basic garden components, in case they are not available in
the community, could be the participation of families in microfinance
programs which could enable them to start a micro garden and generate
income from selling its outputs (Forbes, 2009). This is only an option
in case the families doesn’t want to produce solely for
self-consumption and may need a more elaborated approach on conducting
systematic sack farming in order to guarantee more or less regular
outputs in sufficient orders to generate regular income.
Location
The
advantage of sack gardens and container gardens in general is their
limited need for space due to the fact that many families have no or
only limited space available to establish a garden (Forbes, 2009). The
sacks are naturally placed near the owners house (Radice, 2005) where
they are easily accessible for maintenance and monitoring. Examples for
proper locations in densely populated areas are:
- Rooftops on
flat roofed buildings; if the roof doesn’t support heavy loads, the
bags can be placed on the outer borders of the (flat) roof where it is
laying on the supporting walls.- Doorsteps (Saydee, 2003)
- Vertical sack setup on walls
- Free larger areas near to the house where several families can assemble their bags (Radice, 2005).
(Sack locations, Kibera; Soliratités, 2009)
Plant selection and planting
It
can be observed in several sack gardening projects that solely a single
type of vegetable is planted per sack (Forbes, 2009 and Solidarité,
2009). Other projects suggest a mixed cropping approach like
"chain-planting" which avoids planting large amounts of a single
vegetable per sack but uses the available space for small fields of
different vegetables at staggered intervals (Doshi et al, 2003).
Regarding the selection of plants, several factors have to be taken in
mind:
- a short growing period which allows for several harvests per year (Pascal, Mwende, 2009)
- long term benefits (Pascal, Mwende, 2009)
- selection of traditional plants that occur in the region
- plants which are usually used in the local kitchen (Doshi et al, 2003)
- leafy vegetables are preferable as they keep on growing after harvesting their leaves (Pascal, Mwende, 2009).
- Examples
of leafy vegetables are: Kale, locally planted in Kenya (Forbes, 2009
and Solidarité, 2009); Spinach, Leafy onions, Coriander, Capsicum,
Tomatoes. - Other vegetables and plants used: carrots introduced in
Uganda (Radice, 2005); cowpeas (Radice, 2005); sugarcane suitable and
planted in India (Doshi et al, 2003) - In addition to vegetables,
fruits and herbs seemed to be planted successfully in bags as well.
According to Doshi et al (2003), guava, fig and mango have been planted
in bags already.
- Examples
Soil and Water quality
Especially in urban
environments, pollution of air, soil and water is very common due to
heavy industrial production facilities and insufficient waste
treatment. Finding good fertile soil for sack gardens and urban gardens
in general could be an obstacle and could result in poor outcome of
garden projects. Urban soil maybe contaminated by heavy metals due to
the reception of acid rain over years (Saydee and Ujereh, 2003) and
other industrial pollution.
contaminated soil is the usage of compost which can be produced
individually by using organic kitchen waste, garden refuse, plants
other organic materials. Vermicomposting is one way to make compost
from organic materials (Saydee and Ujereh, 2003). According to Doshi
and Shah (2003), compost can be produced by putting organic wastes into
polyethylene sacks, leaving them until the breakdown of the used
materials into compost is finished.
Compost has a high content of
organic matter and nutrients and by this improves soil structure and
yields in urban gardens. Organic matter in the soil "tends to tie up
heavy metals and render them unavailable to the plants" (Saydee and
Ujereh, 2003) which further improves the quality of planted and
harvested vegetables. Compost also renders chemical fertilizers
unnecessary.
Challenges
A number of challenges arise with the
introduction and usage of sack gardens. The following list is compiled
off conclusions from several projects that used sack gardening for food
production:
- Pests and lack of pest control as well as birds and insects (Saydee, 2003).
- Theft
is often reported (Pascal, Mwende, 2009), although the close proximity
of the sack gardens to the families house allows better monitoring
which could lead to less theft (Radice, 2005) - Destruction by animals
and kids which could be circumvented by fences where space and
resources for their construction are available (Radice, 2005). “Life
fences” using plants and trees are an option where other construction
material is not sufficiently available. - Gaining of necessary resources: sack material, irrigation material, stones, soil, water, seeds.
- Water
access: no access to fresh water may force households to buy water from
water vendors which increase the costs of maintaining the sack garden
of a household. Not every family can afford to buy fresh water for
their gardens on a frequent basis which results in worse plant and
garden conditions with less outcome then with sufficiently irrigated
plants (Radice, 2005). If no fresh water is accessible at all, plants
may suffer from withering in dry periods depending on the region and
climatic conditions (Pascal, Mwende, 2009). - Poor soil quality and
heavy metals in the soil due to urban industrial pollution renders
garden products non-consumable. A possible solution is using self-made
compost which doesn’t exhibit heavy metals or other toxic elements
(Saydee, 2003).
Benefits
Sack gardens can be set up in
just a couple of days and have an immediate impact on the community
(FSN Forum, 2008) as harvest can already be conducted after a couple of
weeks.
Sack gardens provides a mean to produce
food and by that increase the quality of nutrition (Forbes, 2009) where
arable land and garden resources are scarce or not available (FSN
Forum, 2008).
The usage of sacks slows down evaporation of
irrigation water due to for example warm wind which leads to less water
usage (FSN Forum, 2008). Sacks are sealed and only posses holes where
the plants grow out of the sack which limits the area with direct
contact to the outer environment. This attribute renders sacks gardens
appropriate in drought areas where water availability is low (FSN
Forum, 2008). Sealed bags also prevent nutrients from being washed out
quickly from the fertile compost that may have been used to fill the
sack (Saydee and Ujereh, 2009).
(Sack garden, Uganda; Radice, 2009)
Sack gardens can provide the
individual households with additional food for consumption and vending.
Depending on the amount of harvested vegetables several full meals can
be prepared and household income could be increased. Pascal and Mwende
(2009) reports for the case of a sack gardening project in Kibera slum
in Nairobi, Kenya, two to three full meals could be prepared on a
weekly basis and an additional average weekly income of 5USD was
generated by selling yields.
Conducting agriculture is often
well known among parts of the communities in slum areas, due to the
fact that parts of the inhabitants often migrated from rural areas into
the city. They worked as farmers in their home community and posses
knowledge about local vegetation and agricultural techniques (Pascal,
Mwende, 2009). Similar conditions exist for internally replaced people
living in camps which often come from rural areas and posses knowledge
about local agriculture and plants and already maintain small gardens
where sufficient space is available (Radice, 2005).
Low maintenance
time represents a real advantage due to the fact that gardening doesn’t
prevent families from following their daily commitments and duties. It
also means that gardening work itself is not exhaustive and labour
intensive which enables people in bad health conditions, such as
HIV/AIDS patients, to run their own garden and probably benefit from
it’s outcome. This also applies for households with no man labour
available, for example women run households with children, and elderly
headed households (FSN Forum, 2008).
Further Research
Sack gardening is no traditional way
of gardening as it arose by the need of the mainly urban population to
self-produce food. The knowledge about appropriate vegetables and
climatic conditions may be possessed by the inhabitants as local
knowledge, but the application of sack gardening itself still deserves
more investigation related to its general application and local
features (Radice, 2005). The free discussion about sack gardening in
the FAO FSN forum (2008) worked out several suggestions to carry out
systematic research:
- compare sack-garden versus normal production in order to get a better insight in water usage and possible savings
- compare yields
- further analyse advantages and disadvantages of both methods
- identify the amount of sacks needed per individual family for consumption and disposal
- document sack-garden projects and provide corresponding informations, i.e. on websites
Case studies
What
follows now is just a short overview about two projects that
implemented sack gardening in order to increase food security of food
insecure population in slums and displacement camps.
Sack gardening project in Nairob slums (Solidarités, 2008)
| Organisation | Solidarités and WOFAK (women fighting AIDS in Kenya) |
| Year | 2008 |
| Location | three primary villages of Kibera (Makina, Lindi, Kisumu Ndogo) and the whole Kiambiu village |
| Participants | 11073 families |
| Received materials (per household) | 3 sacks, seeds for growing |
| Gender | 82% of the beneficiaries are women, 18% are men |
|
Results per sack |
Sack #1 | Sack #2 | Sack #3 |
| type of vegetable | Kale | Spinachi | Tomatoe |
| number of plants per sack | 40 | 40 | 10 |
| # of leaves harvested per plant | 5 | 5 | 4 |
| number of harvests per month | 3 | 3 | 2 |
| price per leaf (kshs) | 1.5 | 1.5 | 4 |
| monthly revenue generated (kshs) | 900 | 900 | 210 |
| daily revenue generated (kshs) | 30 | 30 | 11 |
Sack gardening project in Gulu distric in northern Uganda(AAH-USA, 2004)
| Organisation | AAH-USA (Action Against Hunger USA) |
| Year | 2004 |
| Location |
two IDP (Internally Displayed People) camps in Gulu districtin northern Uganda, Opit and Amaru |
| Participants | 940 households |
| Received Materials (per household) | one 100kg grain sack, seeds for carrots and spinach or cowpeas, an instruction sheet in the local language |
| Gender | almost all beneficiaries are women |
According
to Radice (2005), the implemented sack gardens served only for self
consumption of the produced vegetables. "37% of the households had
eaten 6 meals or more from their gardens, with an average of six people
taking part in these meals" (Radice, 2005). The amount of harvest of
the remaining households was not mentioned. The conditions of the
individual sack gardens differed noticeable between the two camps.
Where water was scare, in Amuru, the gardens were in worse conditions
than where water was sufficiently available, in Amuru, which led to
worse crop performances due to the lack of irrigation water. 75% of the
households indicated further interest in also selling their vegetables,
as well as eating them in case the program would expand and they could
cultivate in more sacks.