Urban green spaces maintenance without plant health products

The French energy transition law is likely to impact the economic landscape for public authorities – and landscapes themselves - profoundly! As it will no longer be possible to use plant health products for the maintenance of public parks and gardens, alternatives will have to be found! This article explores some of them.

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New rules and regulations for public authorities

Since January 1st, 2017 in France it is prohibited to use plant health products in parks and gardens open to the public. This regulation stems from the energy transition law as it refers to a low-carbon economy (1). And this is rather good news… for the environment, users and operators.

But it also means that the State, local government and public corporations have to find new, greener, groundkeeping solutions. Places open to the public include public parks and gardens, forests, roadway systems and walking trails – but not cemeteries and sports grounds. Zones considered as dangerous, in particular for maintenance personnel, can also be exempted.

And not all products are concerned. Chemical pesticides are prohibited, but the use of low-risk products, usable in organic agriculture or on the biocontrol products list (2) is not limited. But alternatives must be found for all the others.

Differentiated management, a greener - and cheaper - alternative!

In terms of cost for the public authorities differentiated management, which means not using the same care methods everywhere in a given green space, is the best alternative. Why? “The new, particularly manual, green space maintenance methods take much longer than treatment with plant health products” explains agricultural engineer Barbara Dekeyser who works at Aralia.

“As differentiated management is labour-intensive, it costs public authorities more. So rather than mowing 100% of a green space, the idea would now be to mow 25% and to convert the remaining 75% into hay or naturally flowered meadows. In this way public authorities can save time on green space maintenance – and spend the money they save on alternative treatments without forbidden chemical plant health products. But for this to work, it may be necessary to re-landscape the parks and gardens in question – and address maintenance management globally. The idea is not simply to find a greener alternative to plant health products, but also to re-examine the way in which the space is managed. Which new methods to use? On which parts of the space? How to reorientate employee skills and how to train them in new ones”? 

For Barbara Dekeyser, it is essential “to design green spaces differently to build something long-lasting and stop acting from habit”.

Some concrete examples of treatment without plant health products

Today, in addition to differentiated management, there are a wide range of alternatives to plant health products. This means that every public authority is sure to be able to apply the new rules without vastly increasing their budgets. Here are some examples.

New maintenance methods…

• new weeding methods including hydraulic weeding, thermal weeding (steam, infra-red or blowtorch) and mechanical weeding with tools like sweepers, rotary brushes and hoes
• preventive ground cover by mulching or grassing
• ecological grazing, which consists in installing herds and flocks of herbivorous animals in green spaces. For example, goats love knotweed, a very invasive plant
• use biocontrol-validated basic organic products, for example, pelargonic acid which makes plants wither… or use the know-how of insects and worms!
• ladybird larvae and chrysopes (lacewings) are particularly effective against plant lice and aphids.
• nematodes, microscopic worms that devour from the inside the plane tree bugs that cause their leaves to fall prematurely and abundantly.
• parasitoids, like wasps or flies, effectively fight boxwood bee moths.

And these are just a few examples… to maintain green spaces without plant health products there are a host of solutions. Today, it is essential to adopt these alternatives and integrate them into a new green space management philosophy. To save money, respect the new regulations … and our planet!

Our thanks to Barbara Dekeyser for her expert views.

(1) Legifrance, Energy Transition for Green Growth Act
(2) Agriculture.gouv.fr, List of biocontrol-validated organic products
(3) UNEP, Guideline of green spaces maintenance alternatives

Crédit photo : Pixabay / Myriam-Fotos