Welcome to All Nations Food Forest – Melbourne’s First Council Built Community Food Forest Project, and possibly the first in Australia!
In the first part of this case study – All Nations Food Forest – Melbourne’s First Council Built Community Food Forest Project, we looked at how the All Nations Food Forest Project got started, and the motivations for such a project.
In this second part of this case study, we will look at:
- The proposal for the project that was drafted by the community group
- Special considerations for grant funded projects
- Design principles for creating resilient community gardens
- A comprehensive tree and plant selection guide for temperate climate community gardens
- How to avoid common horticultural issues in a community garden to maximise the chances of success
The Project Proposal
The All Nations Food Forest committee completed their final draft of the proposal to council in April 2012.
*A copy of the 15 page proposal in Adobe PDF format has been provided for reference purposes for community groups to use and can be found here
The biggest challenge with getting members of the community to work together on a project is to get them all moving in the same direction, pursuing the same agenda, goals and vision. When the community project involves building anything in public space, the next major hurdle is getting the council/local government to support the project.
To gain council support a community group needs to:
- Put together a solid case that convincingly explains the benefits of the project to the various stakeholders – this is the information that is contained within the project proposal document.
- Provide reassurance that the project is low risk. Councils are more likely to support a project that they believe will work. Providing information on other similar projects that have been done before and have worked eases doubts about the viability of the project proposal.
In this project, the Winton Road Food Forest in Ashburton and the Dunstan Reserve/West Brunswick Food Forest run by our colleagues were examples of working projects we provided to demonstrate that the concept was sound.
It’s also important to convey the scale of the project in comparison to other similar projects, to give the council a sense of perspective of how ambitious the project is and what the relative risk level of the project might be. In comparison to the Beacon Food Forest in Seattle in the US, which covers 7 acres, this small scale project in Australia was a relatively unadventurous low-risk venture.
Intended Project Outcomes
Building a community food forest in public space was not the only intended outcome of this project. Changing the paradigm of urban food production, and influencing council policy on urban agriculture and food security in cities was another. I am excited to report that we have already achieved a success in this second area.
As a result of our proposal and campaigning, along with six years of food forest advocacy that that I have been engaged in since 2008, the concept of food forests was incorporated into the City of Darebin Urban Food Production Strategy, under “Other Urban Food Production Models”. To directly quote the relevant section (page 30) of the document:
Council is open to considering support for a wide range of local food system models where community need and benefit can be demonstrated. Examples of local food initiatives which Council is either already supporting or would consider supporting in the future include:
- Food Forests: Darebin Council is establishing the All Nations Food Forest in 2014, a publically accessible food growing space which is also designed to be a place where the community can share food production ideas, learn new skills and trial new species. A food forest site has been included in the Bundoora Park Master Plan. Food Forests can also be a low maintenance, highly productive feature of community gardens.
This is a significant achievement in itself, and if we can put together a working demonstration food forest then we have met our objectives as a group.
The third project outcome is a highly detailed case study of a pioneering urban agriculture concept, a community food forest built by council/local government in public space. The aim of this study is to provide an impartial and completely transparent report and analysis of the processes, methods, materials and outcomes, to serve as a template for other community groups or local government bodies who are looking to initiate similar projects which aim to extend urban food production in public space.
Since the intention of this case study is to serve as a resource that provides useful information, all efforts will be made to objectively evaluate and analyse all successes and failures encountered in the course of the project.
John and I as two of the three co-founders of this project met with the council stakeholders in late August 2012 to discuss the proposal. Of the four different departments represented at the meeting, three of the four were very positive, enthusiastic and excited to work with us. The collaborative mood created a great feeling of positive expectation for almost all attendants of the meeting.
After we submitted our proposal, the project went silent for almost a year. In mid July 2013, we received the exciting news that Council had $30,000 approved in the 2013/14 budget for the implementation of the All Nations Park Food Forest. John and I were invited to meet with the Sustainability Manager, the Environment Support Officer and a landscape architect from Public Realm, in a meeting to discuss the next steps and timings to progress the project. This was great news and we were looking forward to designing working with the various stakeholders and lending our expertise.
Before meeting the council, it was important to make the necessary preparations, and I’ve detailed below the factors that required consideration before entering into talks.
Considerations for Grant Funded Projects
When working on projects that are funded by grants, where a lump sum of money is made available only once, with no ongoing money provided, a lot of preplanning is necessary to ensure the success of the project.
With our won personal projects, we budget for the initial capital costs, and for ongoing maintenance, and then allocate funds accordingly. With grants all the money must be spent by a specified date, so a different approach is required.
The strategy for ensuring the greatest chances of success with a one-off budget allocation that I came up with was to spend money to:
- Create the highest quality soil possible
- Add as much nutrients and other soil amendments to the soil that can be safely added all at once
- Supply a dependable source of water to the garden beds
The probability of a project succeeding in increased dramatically by thinking through all the steps of the project, foreseeing future problems, and spending wisely to implement measures to reduce or eliminate those problems before they arise.
On a more practical level, let’s have a look at the problems that community gardens encounter and the strategies I formulated for dealing with them.
Design Principles for Creating Resilient Community Gardens
If you can foresee a problem, the wisest approach is to ‘design out the problem’ in the initial stages of the project.
Many food forest project fail for three reasons:
- Insufficient water
- Trees planted in the wrong location or wrong tree selected for the location
- Root competition from allelopathic plants and trees, such as invasive grasses, and trees such as black walnut, eucalyptus, pine and casuarina which release substances into the surrounding soil which actively inhibit growth of other plants
We can address these three key issues in the following ways as detailed below.
Getting the Soil Right
By increasing the organic matter in the soil, both drainage is improved in clay soils, and moisture retention in sandy soils. A nice rich soil full of organic matter stores water nicely like a wet sponge while still letting air to penetrate into the soil. In hot, harsh locations, this can spell the difference between life and death for a tree over the peak of the summer heat. Any initial effort spent improving the soil will pay off in the long term because soil health determines plant and tree health. The soil is not just an inert substance which anchors the roots, it’s a complex living ecosystem which converts organic matter to plant food. Plants have complex beneficial relationships with soil bacteria and as do trees with mycorrhizal fungi, which are associated with tree roots. Rich, healthy, living soil will protect plants from diseases and increase their vigour.
As soil had to be brought in for this project, I specified the following soil mix:
- 2 parts loam
- 1 part organic compost
- 0.5 part organic cow manure
These ratios result in a mix that is comprised of 57% loam, 29% organic compost and 14% organic cow manure.
A worthwhile addition to the soil is Zeolite. It’s a natural mineral that helps retain nutrients and moisture, making the garden beds more drought tolerant and able to use nutrients more efficiently. Landscapers mix it into the soil before they lay down turf, a little goes a long way, it’s quite cheap. Zeolite can be applied at a rate of 250 g – 1 kg per square metre
i specifically advised against a water-saving product called ‘Hydrocell’, it’s a urea-formaldehyde plastic that only helps with moisture retention and has no place in an organic garden system.
Now that the soil can hold moisture well, we need to get the water into the garden in the first place, and this brings us to the next point, water supply.
Ensuring a Stable Water Source
A reliable source of water is critical in ensuring that a community garden survives the increasingly hotter, drier summers that we’re seeing as a result of climate change.
There are several options for supplying water to a community garden. In the Northcote Library Food Garden we use a 10,000 litre rain water tank connected to a pump to drive the dripper irrigation. This system is supplemented by mains waster supply when the tank runs dry.
If no water supply is available, landscaping work can be carried out on sloped land to create contour trenches, also called ‘swales’ in permaculture design, to capture water naturally. You can read about swales and other water capturing systems in my permaculture design articles here.
The budget for this project allowed for an automated irrigation system to be installed, which feeds from the site’s mains water supply. The design specification for this garden was to use drip-line irrigation below a thick layer or mulch, connected to an automated timer. Such a setup can see a garden can see through the hottest and driest of conditions once the plants and trees are established.
If the site has a water supply of any sort, the inclusion of an automated irrigation timer can make a world of difference in a community project. It’s unreasonable to expect volunteers in a community garden to sit in the heat in the middle of summer watering a garden, especially if there is no shade cover to stand beneath. Even if gardeners are passionate, enthusiasm can wane as weather gets more extreme and unpredictable. Here, technology can be very beneficial, though the downside is that irrigation systems can get quite expensive, probably the next most expensive thing after hard landscaping.
Incidentally, hard landscaping is often of minimal value, and rarely of benefit to the plants and trees, but that’s what many projects without informed guidance waste a lot (or all) of their money on, leaving barely any money for soil and plants. This results in a substandard garden with poor soil in a visually impressive garden bed, which is ultimately doomed to fail. I’ve seen it happen before, it happens more often that most people would believe.
With these measures in place, the issue of water should be taken care of, ensuring the greatest chance of survival of plants and trees.
Once the soil and water are taken care of, the next consideration is what any properly built garden should really be about, the living component, the plants and trees.
Selecting the Right Trees
As part of creating a case study which can be used as a template by others, I decided to write up a tree selection guide for community gardens, species that are disease resistant, drought tolerant, require little maintenance and can survive changing conditions which are becoming more prevalent due to climate change. The guide is written for temperate climates,
*A copy of the 9 page All Nations Park Food Forest – Tree & Plant Selection guide in Adobe PDF format which is properly formatted and printable has been provided for reference purposes for community groups to use and can be found here
Here is the content of the Tree and Plant Selection guide, with only web page formatting:
All Nations Park Food Forest – Tree & Plant Selection
List of fruit trees to be planted, variety names and rationale for selection
All Nations Park is a large open space public park built upon a waste disposal landfill site. Constructing a public food forest on such a site imposes certain restrictions on the choices of trees and plants that can be used.
In respect to landfill contamination issues, especially lead and other heavy metal contamination, only plants that have edible fruit are possible to use. Contaminants accumulate greatest in roots and tubers, and to a lesser extent in leaves and shoots.
With a public space food forest, it is important to select fruit trees that fulfil the following criteria:
· Little or no maintenance –trees that are not labour intensive to maintain, and do not require specialized spraying. Peaches and nectarines require seasonal spraying with fungicide and are therefore unsuitable for example.
· Hardy, with tolerance to a wide range of climatic conditions – both in the case of weather extremes and long term changes in climate
· Year round fruiting – to create year-round interest and activity. Early, mid and late season varieties of the same type of fruit (i.e. apples) should be planted to extend the harvest season of each fruit type, and a variety of different fruits that produce throughout the year can be used to provide fruit all year round.
Suggested Trees & Plants
Citrus varieties listed have a wide variety of uses. All citrus trees on regular full-sized rootstocks, as dwarf varieties are too slow to grow and yield very little for such a large scale public edible landscape. All al self-fertile and don’t require a second pollinator tree.
|Lemon||Eureka Lemon – fruits most of the year, produces medium sized lemons, medium sized tree, little if any thorns, one of the best culinary lemons|
|Lime||Tahitian Lime – lime used for juice|
|Orange||Washington Navel Orange – one of the best eating oranges|
|Orange||Valencia Orange – one of the best oranges for juicing|
|Mandarin||Satsuma Mandarin – Japanese variety, large sweet fruit, loose peel, seedless|
|Cumquat||Nagami Cumquat – edible variety favoured by Asian community|
|Other||Calamondin – versatile small fruit, orange flesh, juicy with a fine lime-orange flavour.|
Stone fruit vary in maintenance requirements, and there is a wide range to choose from.
Not recommended: Peaches and nectarines are unsuitable as they are prone to leaf curl, a fungal disease that affects them every spring in our climate, requiring spraying with a fungicide two or three times a year during their dormant season. Apricots are marginal in their disease resistance, they don’t always require spraying, but are prone to several fungal diseases, especially when pruned around damp weather or in the wrong time of year. Cherries are too maintenance intensive for an open space food forest and require a lot of care and netting to return a worthwhile crop.
Recommended: European and Japanese plums are very hardy and vigorous. The larger, juicier plums are generally the Japanese type, while the smaller, oval shaped varieties are European. European plums can be very sweet, with prunes having the highest sugar levels allowing them to be dried without fermenting.
|Stone Fruit||Plum (Japanese)|
|Mariposa||Blood plum, large dark red fruit, juicy, sweet flesh, excellent flavour, mid season. (Requires pollinator – Santa Rosa, Satsuma or Narrabeen)|
|Santa Rosa||Large red fruit, mildly sweet, yellow flesh, excellent flavour, tart until fully ripe, early season (Universal pollinator – self-fertile)|
|Donsworth||Blood plum, large red fruit, juicy, sweet firm flesh, early season.
(Requires pollinator – Santa Rosa, Satsuma or Narrabeen)
|Narrabeen||Large red fruit, yellow flesh, excellent flavour, tart until fully ripe, mid-late season (Requires pollinator – Santa Rosa or Mariposa)|
|Plum (European) – includes related fruit gages & damsons|
|D’Agen Prune||Large oval purple fruit with yellow flesh, eat fresh, best dried, late season (Requires pollinator Robe de Sergeant, Angelina, Green Gage, Coe’s Golden Drop, Damson, President or Sugar Plum)|
|Robe de Sergeant Prune||Medium sized dark blue-purple fruit with very sweet yellow flesh. Used for drying or fresh fruit. (Requires pollinator Angelina, Green Gage, Coe’s Golden Drop, Damson, President or Sugar Plum)|
|Angelina||Small to medium sized purple fruit with yellow sweet, firm flesh, mid season (Requires pollinator Robe de Sergeant, D’Agen, Green Gage, Coe’s Golden Drop, Damson, President or Sugar Plum)|
|Coe’s Golden Drop||Large purple fruit with yellow juicy, sweet, firm flesh, late season
(Requires pollinator Robe de Sergeant, D’Agen, Angelina, Green Gage, Damson, President or Sugar Plum)
|President||Large purple fruit with yellow sweet, rich, juicy flesh, late season
(Requires pollinator Robe de Sergeant, D’Agen, Angelina, Green Gage, Coe’s Golden Drop, Damson or Sugar Plum)
|Sugar Plum||Medium purple fruit with yellow, very sweet, firm flesh, mid season (Partially self-fertile or use pollinator Robe de Sergeant, D’Agen, Angelina, Green Gage, Coe’s Golden Drop, Damson, or President)|
|Green Gage||Small light green fruit with amber yellow, very sweet intense flavour, fruits every second year, mid season (Requires pollinator Robe de Sergeant, D’Agen, Angelina, Coe’s Golden Drop, Damson, President or Sugar Plum)|
Pome Fruits include Apples, Pears, Loquat, Medlars and Quince. Of this group, loquats are particularly drought-tolerant and are self-fertile. Pears and apples typically require another variety as a pollinator, but some varieties are partially self-fertile. Quinces are self-fertile, but are more productive when pollinators are available.
Pears are typically very large trees, unless prunes to size or espaliered, can be impractical to harvest. Dwarf pears are now available and grow 1.5-2m high, these can add interest to the garden and each tree can provide a small quantity of fruit. They can also be mass-planted fairly close together to provide a larger crop of fruit.
|Apples||List of heritage variety apples to be provided by John Pinninger, Heritage Fruit Society|
|Pears||Espaliered full size or dwarf varieties. Williams (Bartlett) and Beurre Bosc are the familiar common commercial pear varieties, green and brown respectively that and are pollinators to each other.|
|Loquat||Champagne loquat – semi-dwarf tree with large round yellow fruit|
|Medlar||Dutch medlar – late season fruit, matures late autumn-early winter|
|Quince||Smyrna quince – Large, pale yellow fruit with a smooth skin and sweet flavour. Quinces are cooked and preserved, used to make quince jelly.|
|Quince||Champion quince – Large, golden yellow, pear shaped fruit with a mild flavour. Quinces are cooked and preserved, used to make quince jelly.|
Other Fruit Trees which are recommended include Mulberries, Figs, Pomegranates, Persimmons many of the drought tolerant varieties, Pomegranates and persimmons are highly ornamental trees. Persimmons have broad, green glossy leaves that change colours in autumn. Some of the bright orange fruit still hang in the tree after the leaves have fallen.
|Mulberry||Black English mulberry – Prolific, long, juicy black-red berries with a sweet, slightly acidic flavour. Berries produced over a short season in late spring. Slow growing very large tree, can be pruned to size.|
|Mulberry||Hicks Fancy mulberry – small, juicy red-black berries produced for three months, maturing in late spring. faster growing than the Black English, grows to 4m x 4m.|
|Mulberry||White Shahtoot mulberry – Long white, extremely sweet fruit to 10cm long. Small, spreading, hardy tree reaching 5m x 7m wide, can be pruned to size.|
|Pomegranate||Pomegranate Wonderful – popular commercial pomegranate variety, medium to large, deep red fruit, juicy, sweet, fragrant. 4m x 4m.|
|Pomegranate||Pomegranate Elche – pink fruit with juicy soft seeds, Spanish variety, 4m.|
|Pomegranate||Pomegranate Gulosha azerbaijani –medium to large sized, slightly elongated fruit with a pinkish hue, with deep red, large and very juicy seeds. Dwarf tree variety grows to 2m.|
|Fig||White Adriatic fig – A green to yellow skinned medium to large sized fig with red pulp and excellent flavour. When tree ripened this fig is unsurpassed with its rich strawberry flesh. Peels very easily when ripe.|
|Fig||Brown Turkey fig – A richly flavoured fig, large size, brown skin with pink flesh, long oval shape. Used for fresh fruit, drying and jam.|
|Fig||Black Genoa fig – Large size fruit with greenish-purple skin. Light red flesh, excellent flavour. A regular bearer of heavy crops. Used for fresh fruit, drying and jam.|
|Persimmon||Dai Dai Maru persimmon – Astringent variety (eaten when soft & sweet), with heavy crops of bright orange, medium sized flat tomato-shaped fruit. Early to mid-season. Large weeping tree with stunning autumn foliage, leaves change to a brilliant, deep yellow and then fiery red..|
|Persimmon||Nightingale (Hachiya) persimmon – Astringent variety (eaten when soft & sweet) with large orange fruit with firm flesh and excellent flavour. Leaves change to rusty orange tones in autumn. Mid-season.|
|Persimmon||Fuyu persimmon (Vanilla persimmon) – Non-astringent variety (can be eaten when hard & crunchy). Large, flattened, deep orange fruit, most popular commercial variety of non-astringent persimmon. Late season – matures during May.|
|Feijoa||Feijoa (Pineapple Guava) ‘Mammoth’ – drought tolerant, productive, ornamental evergreen tree that can be hedged. Fruit is juicy and has a flavour of pineapple mixed with pear, falls to ground when ripe. Mammoth variety produces very large fruit.|
|Cherry Guava||Cherry Guava (Strawberry Guava) – drought tolerant, productive, ornamental evergreen tree. Small dark red fruit with a hint of strawberry and guava flavour have can be eaten fresh or made into fruit pastes, jams or jellies.|
|Lemon Guava||Lemon Guava (Yellow Guava) – drought tolerant, very productive, evergreen tree. Small yellow fruit are sweeter, milder and less astringent, as well as much larger than the cherry guava, and can be eaten fresh or made into fruit pastes, jams or jellies.|
|Jujube||Jujube (Chinese Red Date) – extremely drought tolerant and very prolific, fruit can be eaten fresh (sweet pleasant flavour, crisp texture) or dried (sweet, like a date). Varieties – Li: Large round fruit in mid-summer, best eaten fresh. A narrow, upright tree. Chico: Late season ripening, can be eaten fresh or dried. Well known in Chinese community. Hard tree to source.|
Nut Trees – are typically very large trees, most are much larger than fruit trees, comparable in size to shade trees grown in public spaces. Many have deep tap roots, making them unsuitable for areas such as landfill sites (due to local government issues of roots penetrating landfill clay cap, there is no uptake of contaminants into the nuts). There are still varieties of nut trees that are suitable for landfill sites, such as, almonds and macadamia nut trees.
Almonds are in fact fleshless peaches/nectarines, and therefore only have shallow roots and the same growing requirements just like their relatives.
Macadamia trees are native Australian trees, and are members of the Proteaceae family, the same family as grevilleas and proteas, and share the same shallow, spreading root systems which helps them access water makes them drought tolerant.
Both these trees are available as dwarf trees that can be situated amongst fruit trees. Taller varieties of these trees can be used without issue.
|Almond||Almond “All-In-One” – Dwarf almond to 3m.|
|Macadamia||Macadamia Integrifolia “Lotsa Nuts” – dwarf macadamia to 3m|
The Remaining Critical Elements
The fruit trees alone would create only an orchard, and nothing more. Orchards are maintenance and resource intensive as evidenced by commercial orchard operations. A row of trees does not constitute a food forest, which by strict definition is a multi-layered ecological system of plants resembling a temperate ecosystem model.
Forest ecosystems are comprised of tall canopy trees, with smaller trees below them, shrubs, herbaceous plants, ground cover plants, root zone plants going vertically down, and climbers occupying the space vertically upwards. Most of these layers are required for a constructed food forest to function as a proper living ecosystem, as opposed to a garden.
The benefits of a food forest (natural pest and disease control, minimal labour, very high yields per unit area) are only realised when a real living ecosystem is created that leverages all the natural processes that only exist in natural environments.
As such, the trees form the framework or foundation of the food forest, but the other six layers are required to make it a true food forest, booth nominally and functionally.
In terms of design, we will examine the majority of the remaining layers of a food forest.
Climbers occupy vertical space and can make efficient use of walls, fences, arbours, trellises and pergolas.
|Kiwi||Kiwi – deciduous climber, requires male and female plants (1 male can pollinate up to 6 female plants), and will produce fruit 3-4 years after planting. Require pruning, but do not require spraying with fungicides like grapes do. Leaves are not edible, unlike grape vines, so are suitable over landfill sites with soil contamination issues.|
|Hardy Kiwi||Hardy Kiwi – deciduous climber, more tolerant of cold weather than regular kiwi, produces small smooth grape sized fruit with a flavour of kiwi, banana, strawberry, and pear that are eaten whole. Like regular kiwi, requires male and female plants, (1 male can pollinate up to 6 female plants) and will produce fruit 3-4 years after planting. Require pruning, but do not require spraying with fungicides like grapes do. Leaves are not edible, unlike grape vines, so are suitable over landfill sites with soil contamination issues.
Hardy Kiwi ‘Issai’ is a self-fertile variety (does not require male and female plants) and will fruit after first year of planting.
Shrubs occupy space below trees and above herbaceous and ground cover layers.
|Blueberries||Evergreen & deciduous varieties available, prefer acidic soil, full sun.|
|Currants||Blackcurrants, red currants, white currants and gooseberries require morning sun, afternoon part-shade and are shade tolerant.|
Herbaceous layer plants occupy space below shrubs and above ground cover plants.
|Herbaceous||See companion plants category below|
Groundcover plants protect the soil, prevent weed growth, and act as a living mulch to reduce water consumption and keep tree roots cool in summer.
|Groundcovers||See companion plants category below|
Additional Plant Categories:
Companion Plants are beneficial plants that assist the growth of other plants and trees, repel pests and increase resistance to diseases.
|Companion Plants||Companion plants can belong to all categories or levels of a food forest schema. Extremely useful deep rooted companion plants such as comfrey are not included due to the contamination and soil depth issues.|
Dye Plants are plants which can be used to produce dyes for colouring fabrics. Food forests can contain plants and trees that serve many other human needs, such as sources of fibres for textiles, fabrics, rope and cordage. Plants which can yield natural dyes was such a useful category of plants which the community expressed interest in.
|Dye Plants||Extensive lists are available with many plant varieties for various colours. Each plant has to be assessed for its suitability in the garden, this is a sub-project in itself, depending on the scale of a dyer’s garden. A small scale area can be set up with some suitable plants as listed below.|
|Agrimony, Bilberry, Bugle, Dyer’s Chamomile, Elderberry, Meadowsweet, Motherwort, Queen Anne’s Lace, Sweet Woodruff, Tansy, Tormentil, Turmeric, Dyers Woad|
Other Edible Plants which have shallow roots, which is essentially the majority of them, excluding the deep tap-rooted exception, can be included in the elevated beds around the fruit trees, as they will not be able to reach the bottom of the 1.5m elevation of soil in the constructed beds.
Possibilities include all culinary herbs, such as thyme, sage, oregano, rosemary, marjoram. These are all low maintenance plants that comply with the design requirements. These plants also attract pollinators such as bees which ensure pollination of fruit trees. Edible perennials greens such as Lebanese cress, Salad Burnett,
Most annual vegetables and herbs require constant attention and care and can look untidy very quickly, so are not suitable. Perennial systems have lower nutrient, water and care requirements; hence the focus on perennial plants in true layered food forest systems.
Listed below are a variety of perennial edible and other useful plants that can be used to construct a low maintenance produce garden. All root and leaf crops are unsuitable in contaminated soil sites, as are deep rooted varieties even with elevated beds. This list is only included to illustrate the some of range and variety of perennials available for a community garden
With appropriate plant and tree selections, the chances of survival are maximised, providing the best chances for the garden to thrive.
Plant and tree selection for this project accordingly was based on this guide in order to maximise the resilience and biodiversity of the food forest.
The last step for maximising the chances of success in a community garden is to eliminate the factors that actively work against it. The last thing any community garden needs is competition from invasive plants and trees.
Keeping Out The Competition
To ensure the best chances of success for a garden in public space that cannot be monitored daily, all unnecessary competition needs to be removed, and the main one is grass!
If grass encroaches into the garden beds, put in place root barriers if possible, otherwise mulch heavily to prevent incursion by invasive running grasses and wind-blown annual grasses which spread by seed.
Any bare soil is an open invitation for Nature to fill that space with whatever is blowing in the wind in order to stabilize the exposed soil and prevent erosion. The plants that stabilize disturbed soil are pioneer plants – what most people refer to as weeds. Mulch prevents unwanted plants growing in garden beds and also saves water. There is no reason to have exposed soil, ever!
The idea of energy efficiency is critical in sustainable gardening, and the system of permaculture takes energy efficient garden design to the highest level. In any case, the garden should need the minimal of labour and input of resources. Weeding is wasted effort, and if it can be avoided, then all precautions need to be taken at the early stages of any project, because a little extra effort in preparation will save lots of ongoing, wasteful effort in the long term.
Root barriers were specified in this project as the site is surrounded by kikuyu lawns. The deeper the plastic root barriers, the better. Here are two invasive summer-growing running grasses which are often encountered in community garden sites, their root depth details should explain the need for controls.
Kikuyu (Pennisetum clandestinum) roots will go down 50cm deep, manual removal is difficult as any broken pieces of the thick surface runners or underground rhizomes will regrow.
Couch grass (Cynodon dactylon) root will typically go to a depth of 15cm, spreads by any fragments of its thin, string-like stolons or rhizomes, and can also often produce seeds under stress conditions such as drought.
Another problem for food gardens are large trees with invasive root systems which get into the irrigated garden beds.
Eucalypts are especially problematic because they have very invasive roots which suck the soil dry, and also secrete allelopathic chemicals into the soil which reduce the growth of nearby plants .
Most tree roots spread 2-3 times the radius if the canopy, and often reach out 5 times the radius of the tree canopy or more.
You can use this formula to determine how far the tree roots might reach, which is easier than digging, before selecting a location for a garden bed.
The only other option is to remove the offending trees, which is less likely an option in most cases.
Site selection is critical in minimizing unwanted competition from invasive grasses and trees with aggressive roots. It’s much easier starting in the right location and making any necessary changes before commencing construction.
In the next article, we’ll look at all the various aspects of the design - the design process, the various design issues and how they were resolved, and the critical elements of food forest design, which you can read here – All Nations Food Forest – Understanding the Design Process
Please feel free to comment or ask questions on any aspect of this project, thanks.