Growth regulators Start to think about the use of growth regulators on nursery stock if you have not used them before. The cost effectiveness of spraying set against the cost of hand trimming shrubs is very economical.
Topdressing Start applying topdressing to over-wintered container plants that do not have the longer lasting CRF products. Use a granular product such as Sincron, Osmocote Top Dress or CRF plugs. Applications of topdressing can destroy the herbicide layer at the point of application; you may need to consider a herbicide application around three weeks after the topdressing application to avoid new weed growth.
Adelgids These are an often forgotten pest of conifers. They produce a white, fluffy mass on the needles of pines, junipers and Cedrus. While they do little harm to the trees, they are the source of so called "pineapple galls", which can disfigure otherwise good trees. Spray any signs of this pest with Hallmark with Zeon Technology or Gyro and include a wetting agent to get good penetration of the pesticide.
Rust mites Malus, plums, ash and Sorbus aria should be sprayed with Dursban WG to control rust mites and other bud damaging mites.
Biological control Predator programmes should be started now for whitefly, aphid and western flower thrip. Check which aphid you are seeing as the selection of the right predator is important to achieve success. Sticky traps should be distributed around now to monitor the pests present on your crops.
Heater damage Unvented, direct-fired oil heaters can create a build-up of sulphur dioxide, while propane-fired heaters can cause ethylene build up in the structure. Both these can result in damaged foliage of young plant material. It is even more important at the moment to open your tunnel doors or glasshouse vents, even if it is only for half an hour a day to bring about an air change in the structure.
John Adlam is managing director of Dove Associates.