Mites: I have seen quite a lot of mite eggs on field-grown ornamental trees, particularly cherries, in the past week. Malus, Prunus, ash and Sorbus aria can be sprayed with Dursban WG, Hallmark WZT (SOLA 2008-2944), Envidor (SOLA 2009-3366) or Dimilin Flo to control rust mites and other bud-damaging mites.
Sustainable use of pesticides: A consultation on implementing the new European rules on pesticides has just been issued by the Chemical Regulation Directorate (CRD). It includes options on protecting water, sprayer testing, competence training and the use of integrated pest management. It is important that we all contribute to this consultation and we have until 4 May to get our views to the CRD.
Azalea gall and leaf curl: With the damp time we have been having, spray Croptex Fungex at the first signs of the white puffy growths on leaves, stems and even flowers of Azaleas. Spray Croptex Fungex or Serenade ASO (SOLA 2009-0246) to control peach leaf curl. Include damsons and greengages to avoid pocket plums, which is a related disease.
Scale insects: Imports have led to an increase in this pest particularly on yew, ivy, Euonymus, citrus and Camellias. Not all scale is actually alive at the moment - mum lays her eggs, lies on top of them and dies. Certis Spraying Oil is the only product that is effective at reducing the eggs or juveniles under the shell during the winter months on ornamentals - avoid use in frosty conditions. Decis or Chess WG (SOLA 2008-2834) are effective on mobile adults. Use Savona for protected edible crops.
Adelgids: An often forgotten pest of conifers that 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 Dursban WG, Hallmark WZT (SOLA 2008-2944) or Talstar 80 Flo and include a wetting agent to get good penetration of the pesticide.
Clematis: Drench newly potted Clematis with Aliette 80WG followed by Scotts Octave a couple of days later, as a precaution against wilt.
Biological control: Predator programmes should be started now for whitefly, aphid and western flower thrip. Check which aphid you have - the selection of the right predator is important to achieve success. Sticky traps should be distributed around now to monitor pests present on your crops.
John Adlam is managing director at Dove Associates www.HorticultureWeek.co.uk/nursery for recent articles