Tangled tendrils of knotweed management

Heavy fines face property owners and businesses who leave it unchecked

22 November 2016

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As most landowners, both agricultural and residential will know, knotweed can pose a significant liability and even adversely affect land values. An alien species which is illegal to plant, it is destructive, invasive and extremely resilient. It strangles and suffocates other plants, cracks concrete and is very hard to get rid of, making treatment costly and difficult. Heavy fines face property owners and businesses who leave it unchecked. So what can be done to get rid of it?

There are a number of options for knotweed treatment, with comprehensive guidance set out online by the government. Often a combined approach of spraying with herbicide, and herbicide stem-injection, is used by contractors.  Of course the more intrusive the solution, the more costly and potentially more damaging to the land itself. Wholesale excavation and removal of the site on which the knotweed stands, for example, can be effective but can result in removal of adjacent hedgerows and fencing, with associated ecological impacts.

For landlords or agents of tenanted land, who find themselves in a position where management is required, there are a number of points to consider:

  • In view of the significant expense involved in treatment, it is always worth checking the tenancy agreement to see whether the landlord or tenant bears the burden of treatment, or consider sharing the cost of the liability. It is also worth getting a number of contractor quotes for comparison purposes, and ensuring they have accreditation.
  • The most effective time of the year to get contractors in place to commence treatment is July to September, as late springtime treatment may adversely affect pollinating insects, and during the winter period there are no leaves so the herbicide will have limited effect.
  • The full programme of treatment will require repeat visits over a number of years, so landowners will need to accommodate this when negotiating arrangements with new or existing tenants.
  • Signage and fencing should be a priority to prevent further spread, and any farming activity in the vicinity of the knotweed should be halted or kept to a minimum, since disturbed land and contaminated equipment can speed up the spread of the disease. Any sitting tenants should be asked to cordon off and avoid the knotweed areas until successfully treated.

Rhian Howells, Surveyor with Cooke & Arkwright’s Land Agency comments, “Landowners and property owners should be constantly alert for any appearance of knotweed - a fleshy red-tinged shoot with heart shaped green leaves - as it can appear without warning. Get expert advice as soon as possible as the earlier it is caught the better the chances of dealing with it successfully.”

Mansford has expanded its investment portfolio over the last few years. Over this time Andrew West has provided us with a full rating valuation service which has involved giving a view on liabilities prior to acquisitions, as well as conducting negotiations with Valuation Officers on our UK estate. The portfolio includes a wide range of properties from shops, offices and pubs to major leisure schemes. He has been particularly successful in mitigating our liabilities to empty property rate, which has been an issue on acquisition prior to implementing our development and letting strategy. I have no hesitation in recommending Andrew's expertise in rating valuation for all property types. The profile of property within his portfolio and the successes achieved are testament to his position as an extremely accomplished rating practitioner.

Leopold Hall, Partner, Mansford LLP