Mites Check Alnus, Fagus, Fraxinus, Pyrus, Quercus ilex, Ribes, Sorbus or Viburnum for signs of blister and felt mite damage. Apply Hallmark WZT (EAMU 2008-2944), Dynamec or Envidor (EAMU 2016-0997) if seen.
Fireblight Check Rosaceae subjects, especially ones that bore flowers last year. Prune and burn all suspect plant material. Cold damage and old scab infections produce similar symptoms.
Predators Use an IPM approach to control pests, diseases and weeds. For pests on protected crops, use products with short persistence such as Aphox, Majestik, Savona, SB Plant Invigorator, Spruzit or Pyrethrum 5EC before introducing predators.
Leaf-curling aphids Control on ornamental cherries and other plants such as Viburnum carcephalum with Calypso (EAMUs required), Chess WG (EAMU 2013-2016), Gazelle SG or Movento (EAMU 2011-1987), which will provide good control even after pests have distorted the foliage.
Western flower thrips Control scratching or flecking damage on foliage and flowers with Conserve, Dynamec or Naturalis-L. Control using Amblyseius andersoni, A. cucumeris, A. montdorensis and A. swirskii mites or Orius spp. on foliage and Macrocheles robustulus mites on soil or growing-media surfaces. For additional control, choose Gaeolaelaps aculeifer or Stratiolaelaps scimitus (formally Hypoaspis miles). Steinernema feltiae parasitic nematodes can be applied to foliage, soils and growing media depending on the pest life stage. Control products include Actara (EAMU 2014-0186), Calypso (EAMU 2014-2151), Conserve, Decis (EAMU 2014-1011), Dynamec, Hallmark WZT (EAMU 2008-2944), Majestik, Naturalis-L, Pyrethrum 5EC, Savona, SB Plant Invigorator, Spruzit or Toppel 100 (EAMU 2015-1454) depending on location and use of predators.
Caterpillars Install pheromone lures (in Delta traps) over vulnerable protected crops to identify damaging caterpillar species. This helps with tortrix moths and timely insecticide applications. Control pests on outdoor Betula, Cratageus and Carpinus using Decis, Dimilin Flo, Insegar WG, Runner (EAMU 2012-0448), Explicit (EAMU 2011-2090), Toppel 100 (EAMU 2015-1454) or Tracer (EAMU 2008-2908).
John Adlam, Managing director, Dove Associates, HorticultureWeek.co.uk/nursery