Specifying works, materials & planting stock: Frequently encountered problems

    Control measures
Contractors who do not work to the timetable specified or to the methods required 
Employ a clerk of works who will check and sign off works as satisfactorily completed. Always issue clear, unambiguous and written specifications. Where possible, make the contractor responsible for a successful outcome three years after establishment: build this into the contract.Always employ appropriate specialists to specify and clerk works for complex projects.
Contracts can over-run on budget because the works have been poorly specified.  
Always plan the project well, and work out the detailed costs and methods properly. Seek expert help when needed.
Inadequate ground preparation owing to bad ground conditions, that prevent machinery from entering land. (A problem on recently restored surfaces such as landfill sites and infilled gravel workings, as well as agricultural land on heavy clays.)
 Have a plan “B” in place.
Planting is delayed, then carried out at the wrong time – leading to poor establishment. 
Have a plan “B” in place. For grasslands, if sowing is not undertaken in autumn, consider waiting until the following March or April or delaying until the following autumn. You may need to undertake an additional cultivation and/or apply a broad-spectrum herbicide to weeds that begin to germinate from the seed bank. Alternatively,  to stabilise the site you could sow a low rate of perennial rye grass which can they be sprayed off the following year. This would be important where sites need to be rapidly stabilised, e.g. landfilled areas or new flood banks.
Unfavourable weather, especially drought, can be a reason for establishment failure and this is a risk with any project where seed is to be sown or plants established. Spring sowings can be at risk from drought.
Suitable planting stock is unavailable
Plan your plant and seed requirements well ahead - do not order at the last moment! Discuss your requirements with suitable suppliers at least six months ahead (more for large, complex schemes).

Consider temporary vegetation establishment (see above) until the planting stock you want is available.

See BTCV handbooks for information on materials and planting methods related to projects for ponds, wetlands, dunes, fencing,walling and hedges and much more.



Page last modified on Friday 22 of June, 2012 18:41:27 BST