Western flower thrip: Check for the tell-tale scratching on the foliage of bedding plants, roses, fuchsia and clematis. Blue sticky traps and lures can help to monitor susceptible crops. Under protection, use Amblyseius spp. if temperatures are stable. Control pupae with Hypoaspis or Macrocheles mites or the rove beetle, Atheta coriaria. Use Conserve, Dynamec, Naturalis-L or Nemolt (SOLA 2010-2131) with predators. Nematode drenches can control the larva.
Planting quality: The quality and standard of tree and shrub planting can make all the difference to establishment - we all know it but do not always do it. Good drainage prevents waterlogging and aeration of the root area - roots breathe too. Make sure that staff are trained in correct hole preparation, including attention to any compaction around the hole and drainage of the planting area.
Bifenthrin: All remaining products have an end use and storage date of 30 May 2011.
Bees: Notify nearby beekeepers if crops are sprayed in flower. Damage to colonies can involve court action by the Health & Safety Executive.
Dianthus: Newly-potted dianthus may need a directed spray to the crown of Prestop, Scotts Octave, Serenade ASO or Switch to control Fusarium spores. Sciarid larvae can damage roots straight after potting so apply nematodes, Hypoaspis or Atheta.
Two-spotted spider mite: Keep Phytoseiulus applications going on vulnerable crops. Add in Amblyseius californicus for warmer days.
Edible crops: Remember that although some crops are grown as ornamentals they are still considered to be edible with specific harvest intervals, which must elapse prior to despatch. A considerable list of SOLAs relates to outdoor and protected herbs too, which must be printed off and read before application.
Thuja: Needle cast disease (Didymascella) causes fronds to go brown. Dark-brown spots on the upper surface of the foliage spread down through the tree. Control with Scotts Octave or Signum (SOLA 2009-1842) at three-weekly intervals until the end of July.
Impatiens downy mildew: On all impatiens cuttings brought into the nursery, make sure that they are given a spray of Fubol Gold (SOLA 2010-2567) as a precaution against impatiens downy mildew.
John Adlam - Managing director, Dove Associates