Edible/Useful Street Trees?
- This is an email which appeared on the International Permaculture email list some
time back- I had Russ' permission to polish it up into an article, including some
info on possibly suitable UK species, but never seem to have gotten round to it, so
thought I'd submit this for information/discussion here as I thought the points he
makes are very interesting and universally aplicable even though written for an
Any other subscribers got any thoughts on suitable edible/useful street trees?
> Do you know of any communities where there has been a policy to plantI seem to remember that carob trees - I think - were planted as street trees
> street trees which produce edible crops (any where in the world)?
in a town in Victoria, Australia. The carob, you probably know, favours dry
conditions, produces an edible pod used as a chocolate substitute and has a
foliage useful as fodder.
That was in the 1980s, so my memory is a little hazy. It might have been
reported in an early Permaculture International Journal. The town might have
Once, I raised the idea of edible street trees during a presentation I made
at a Newcastle conference (1996) - a followup to the Rio conference. A
Sydney council planner in the audience, while not arguing against the idea
of edibles as street trees, raised the issue of maintenance and suggested
that councils would be better waiting for an approach from residents before
carrying out such plantings.
Maintenance, of course, is a valid point because many edibles would require
more maintenance than non-edible street trees.
In the early 1990s, the idea of planting fruit trees in a park in
Leichhardt, an inner-urban Sydney suburb, was put forward by a council staff
environmental policy developer. It was local residents who declined the
proposal but who agreed to a grove of olive trees in recognition of the
substantial Italian presence in the suburb.
In a nearby suburb there are Australian bush food trees - a fruiting variety
called Illawarra Plum (not a plum at all although the fruit has the colour
and texture of blood plum) - they are Ecocarpus and are indigenous to Sydney
bushland and other areas. They drop their fruit in Autumn. These trees
receive no maintenance and the fruit makes good eating. They are, of course,
'accidental' edible plantings.
A FEW POINTS
May I make a few points about the use of edible fruit trees as street tree
(and presumably parkland) plantings?
1) If fruit fly is prevalent in your climate, avoid fruit tree species
susceptible to the fly. This will reduce the chance that the street trees
become vectors for the infection of home garden fruits. Consider the
prevalence of other insect pests of plant diseases.
In Sydney, residents have sometimes planted the delicious tropical fruit
locquat in their home gardens and on streets. Unfortunately, locquat
harbours fruit fly although it casts a welcoming shade in summer and has
attractive, apricot-size, sweet fruit.
2) In Australia, councils struggle to keep expenditure consistent with
income. Any species should therefore be economical in regard to maintenance,
so select low-maintenance species.
3) Before planting the trees, think about fruitfall and whether this will
stain car paintwork or cause other negative impacts which would lead to
pressure on council to remove the trees.
4) Non-edibles may be more appropriate along busy roads in case the fruit
become contaminated with hydrocarbons from the traffic. In Australia, leaded
petrol has been phased out but may be a consideration in other countries.
5) Suggest that councils, in deliberately selecting edibles as street trees,
also develop a policy of access to the pickings by citizens. This would
head-off any entrepreneurial fruit dealers from gaining 'official' access to
the harvest and excluding citizens.
6) Over the past decade in Australia there has been an increasing interest
in native 'bush' foods. Bush foods therefore make a good candidate for
street and parkland plantings.
If there are groups of native food plant enthusiasts, perhaps they could
suggest particular suitable species and may even be encouraged to help in
maintenance and to keep an eye on the plantings.
A further advantage of bush foods native to an area is that they are adapted
to regional climate and soils.
7) Consider nut trees as street plantings. One thing going for nuts is that,
with the edible part safely enclosed in a shell, they are not susceptible to
contamination by vehicle exhaust.
In Windsor (Brisbane, Australia) I was shown a few of the native macadamia
trees now well established as street trees.
8) In rural areas, consider using trees which produce a foliage useful as
fodder (I mentioned carob earlier). That way, when the next El Nino brings
drought to the land, council can harvest a portion of the foliage as
emergency fodder for farmer's cattle. This should engender public support
for the plantings.
9) Consider - as a supplement to edible street plantings - the establishment
of edible groves in parkland. Like street plantings, parkland orchards
should consist of low maintenance species.
Some bush food trees are used widely in Sydney as ornamental plantings in
home gardens and parks.
Within walking distance of where I live I can collect Illawarra Plum,
magenta lillypilly (Syzygium paniculatum), small leaf lillypilly (Syzygium
leuhmannaii) and bunya pine seed (Aracaria spp), not to mention the creepers
pigface and New Zealand spinach (Tetragonia tetregoniodes) on the beach
The notion of planting fruit trees as street plantings in some parts of
Australia is likely to generate opposition from the influential native
plants lobby. They, of course, would rather see native species established,
preferable indigenous species.
This idea has merit - especially where pollution from vehicles may
contaminate fruit and as a reservoir of genetic information for those
Trouble is, some of this lobby treat any exotic species as weeds - they are
somewhat weed obsessed and at times their eradication of exotics resembles
nothing more than the ethnic cleansing of the plant world.
While the establishment of native bush foods might go some way to mollifying
them, you should be on the lookout for opposition and their lobbying of
council, with whom they are particularly influential.
Because they are supposedly interested in environment and sustainability, a
counter to their opposition might be to point out that local food is
nutritionally beneficial and to also point out the environmental and social
costs of importing foods into the city. A city in which the majority of
plantings are native species does little to reduce this impact because it
simply furthers the need to rely on the hinterland for food. Use the
'ecological footprint' model.
I think it was David Holmgren who wrote that many proposals by pemaculture
designers for public place plantings have not been taken up because they
involved high maintenance and were seen as impractical. Thus, quality of
advice when considering species selection should be valuable.
It might also help in convincing local residents that they would not be
inconvenienced by the plantings. Yes, street plantings, like most
initiatives in public places, have a public relations component. Identifying
potential objections and developing arguments to counter them would be time
well spent. Just because an idea is of blazingly obvious benefit doesn't
mean that everyone will see it that way.
The idea of edible or otherwise useful street tree and shrub plantings is
one which has been around the permaculture movement for some decades. It's
also one which has never taken off, apart from a few instances, some of
which are accidental.
Hope your research goes well.
PACIFIC EDGE PERMACULTURE
Media, training and consultancy services for sustainable development.
PO Box 446 Kogarah NSW 2217 Australia
Phone/ fax: 02 9588 6931 pacedge@... www.magna.com.au/~pacedg
- I travelled to Moscow, Russia, recently. Apples were commonly used as
street trees there, although due to fruit drop and other problems, I
don't recomend this. Basswood (Tilia species) are commonly planted in
Chicago. No one uses them, but the flowers could be used in tea.
Frankly this seems more hazardous, in re. urban air pollution, than
fruit because of the higher surface area (exposed to smog) to volume
ratio. I've never seen *intentional* edible landscaping of any sort
practiced in Chicago, though. Do New Englanders tap their street
maple trees? I forsee a "tragedy of the commons" problem arising
since (at least in the Rust Belt where I currently live) property
rights to streetside areas have eroded to the point where they are
practically city property.
Street hedges seem to pose less of a hazard from fruit drop. Many
plants seem suitable: nanking/bush cherries, Rosa rugosa, kumquats
(subtropics), highbush cranberry (esp. for shade), even severely
pruned mulberries. However shrubs don't shade drivers from the summer
sun. Again, the "Commons?"