Organic options

The National Trust is demonstrating that amenity land can he managed without the use of any synthetic chemical pesticides. The meadows  of Morden Hall Park have never been exposed to pesticides or fertilisers. The park is now a thriving and popular visitor centre and an urban conservation haven in South London.

Photo: Organic management at Morden Hall Park - turning the hay

Morden Hall Park in South London has been owned by the National Trust since 1941. The previous owner had a general dislike for newfangled ideas hike cars, fertilisers and pesticides and so did not use them. The result was the development by default, rather than any strategic planning, of a particularly important ecological site on the fringes of London’s suburbs.

    Until about five years ago Morden Hall Park was managed on a low-key basis jointly by the National Trust and the London Borough of Merton. The National Trust took over sole management with decisions that the ecological value of the park would he maintained and public access would be balanced with this approach.

    Three years ago the first hay crop was cut using equipment bought by the National Trust specifically for that purpose. The annual programme of management and maintenance now includes a single cut of the hay meadows taken late in the summer to allow wild flowers to seed and butterflies to complete their life cycle.

No pesticides or fertilisers

The site manager, Paul Rutter, was trained in countryside management, and recognises the importance of the ecological balance of the Park. ‘Pesticides and sprays have done an awful hot of damage’ he says, ‘so we want to avoid using them.’ No fertilisers or pesticides are applied to the meadows. This creates the conditions that promotes the growth of less vigorous plants such as cowslips, oxeye daisies and birds foot trefoil, and the fauna that accompany them.

    The only chemical pesticide used in the park is glyphosate. About two knapsacks of this are used a year, mainly to bring knotweed under control. Once the knotweed is brought under control an environment will he created which will out-compete it and prevent its re-emergence. Even the very small amount of chemical currently used will therefore no longer be needed.

    Knotweed, like other less desirable plants such as hedge parsley, cleavers or goose grass is a sun lover. An extensive programme of tree planting in the Park will eventually produce sufficient shade to discourage these species and allow less competitive desirable species to succeed.

Community weeding

Some 1500 trees have been planted over the past three years, and the planting continues. To protect the young saplings, bark or wood chip mulch is laid around their bases. Tree bases are also weeded until the saplings are taller than the surrounding vegetation. They are then left since the surrounding vegetation protects the young trees from dogs and people.

    Thistles and hogweed are targeted for treatment in the meadows. This generally entails manual removal using hoes or hooks, or topping with a mower. Repeated cutting of these sun lovers and nettles also eventually allows desirable species to come through and overwhelm them. Cutting or roguing carried out when the ‘weeds’ are at their maximum vigour seems to keep them under control for long periods.     

    Weeds from the bases of young trees and the meadows are manually removed by Park staff and volunteers. Local schools and community action groups are keen to help in maintaining the site. This helps to keep labour costs down but also provides the community with a stake in the Park. Manual weeding at the right time can be extremely efficient, but it is important to remove material from the site to prevent re-rooting.

Public access

While the Park is maintained as an ecological haven, it is also a popular public place. Balancing the needs of visitors with those of the wild flora and fauna can be difficult. The management of Morden Hall Park make a point of explaining why the grass is left long, and point out the ecological value and rarity of the site. There are no keep off signs but rather a policy of educating visitors by giving information about the value of the meadows and how to use them. This seems to work well, and there is very little abuse of the trust given to visitors. The edges of meadows and paths, which visitors have naturally selected, are mowed to provide easy access to plenty of green space. Some other areas are cut for amenity use and for presentation. This seems to compensate adequately for the exclusion of access to other areas.

    Morden Hall does not attempt to offer what other public parks offer in the way of playing fields and other facilities. It aims to complement other parks by providing access to traditionally maintained meadows full of wild flowers, insects and birds, which cannot be found elsewhere.

    A rose garden in the Park is also maintained organically. Manure is applied as fertiliser and weeding is carried out manually. Black Spot and Rust do occur, but in the words of Paul Rutter ‘we can live with it’.

    What Morden Hall Park demonstrates more than anything is that amenity land management without chemicals is not just an ideological dream: it can be done. (MD)

For more information: The National Trust. Southern Region. Polesden Lacey, Dorking, RH5 6BD, UK, TeI:+44(O)I81 648 845.

[This article first appeared in Pesticides News No.27, March 1995, page 11]