The fungus can overwinter on fallen leaves and re-infect trees in the spring. Dark, black patches develop and new bud growth can be killed off. It is often worse in cool, wet springs, so if you saw large dead patches along the main leaf veins last year, make sure that you apply a preventive spray in early spring with Bravo 500 (EoA 2011-1130) or mancozeb.
Azalea gall: Watch for cool, damp conditions and spray preventively with Serenade ASO (EoA 2009-0246). If galls are present, pick them off, improve air flow around the plants and spray with Signum (EoA 2009-1842).
Lighting: Supplementary lighting over some crops can be useful if light levels are low. Lighting stock plants for earlier cutting production or encouraging seedlings to establish quickly can provide a quick payback for the initial investment. Make sure that the lighting is used with adequate heating to promote balanced growth. See www.growsave.co.uk.
Dianthus: Newly-potted dianthus may need a directed spray to the crown of Prestop, Scotts Octave, Serenade ASO (EoA 2009-0246) or Switch to control Fusarium spores. Sciarid larvae can damage roots straight after potting - apply Atheta, Hypoaspis, Macrocheles or nematodes.
Biological controls: Plan your programme to get orders in on time - the mild winter will encourage earlier whitefly, aphid and mite populations. Sticky traps will help with monitoring whitefly, thrip, sciarid and leafhopper. Introduce a mix of Encarsia and Eretmocerus (whitefly) and Amblyseius cucumeris (thrip) as soon as you see pest activity.
Winter protection: Keep air flow going around protected crops to prevent still air and unnecessary spraying for Botrytis infections - open doors and vents when weather permits. Keep fleece or Cosytex over vulnerable crops to prevent cold, wind or drought damage.
Pruning: Clear and burn your on-site tree and hedge prunings to prevent coral spot and stem canker infections. Burning wood in the open requires agricultural waste exemption D7. Alternatively, chip or pulverise the wood (exemption T6) for beneficial re-use on agricultural land using exemptions U10 or U12.
John Adlam, Managing Director, Dove Associates