COSHH assessments The control of substances hazardous to health assessments you carried out in the past do not last forever. If you have replaced your sprayer, changed your chemical store or added an acid injection unit, then a new assessment needs to be carried out. Your health and safety policy should also be up to date. If you have removed hazards or put up new buildings that may have created new ones, the statement should be amended accordingly. Risk assessment in respect of workplace equipment both in the office and on the nursery should all be up to date. Use the winter months to review points that are covered by legislation.
Botrytis Check that ventilation fans are running in tunnels and glasshouses — this is one of the most important times for them to be fully operational. Open your tunnel doors at least once a day for a short period to change the air and control the humidity.
Mains water If you are a nursery using mains water, then check your water bill for sewage charges because you may find that they are based on your water meter readings. This is fine in a factory or domestic environment, but in a nursery or garden centre it is not representative because you use more water for crop work and have a reduced flow of sewage from the site. Look at your bill and see whether your sewage charge is equal to and calculated from the water meter reading. If so, there is scope to reduce the sewage component.
Conifers Consider applying Certis Spraying Oil to conifer plants or hedges that suffered aphid damage earlier this year. Do not apply if frost is present or forecast and make sure that the product penetrates the centre of the plant. If you have conifer hedges alongside the roadway that are always damaged by salt, spray them at least monthly through the winter with Orosorb or Wiltpruf S600 to coat susceptible needles.
Aphids These pests are still alive on some protected crops and acers. Control at this time of the year can often be effective by fogging because it reduces the amount of water you apply to the crop. Consider applying Chess WG (SOLA 2008-2834), Decis, Majestik, SB Plant Invigorator or Stalwart.
Rust This disease can often be a problem on Mahonia 'Apollo' Award of Garden Merit during December. Spray Nimrod, food-grade potassium bicarbonate or Systhane 20EW.
John Adlam is the managing director of Dove Associates