Weed control Spot-treat perennial weeds on new land prior to planting using products such as Dow Shield 400 (EAMU 2013-0514), Roundup or Garlon 4. Volunteer cereals and couch grass can be controlled later when they are growing using Aramo (EAMU 2008-2813), Falcon or Laser.
Bark beetles Spray stems of outdoor pines and ornamental prunus with Dursban WG to control emerging pests.
Leaf spots Protect newly emerging foliage on outdoor crops using Bravo 500 (EAMU 2011-1130) or Dithane 945 (EAMUs required). Focus sprays on crops affected last season.
White blister Check in humid tunnels on ornamentals from the brassica family including alyssum, arabis, aubretia, Erysimum and Hesperis. Improve air flow and apply Amistar (EAMU 2009-0443) or Signum (EAMU 2012-2141) if seen.
Caterpillars Hang pheromone lures in Delta traps over protected crops to identify damaging species. Apply Conserve, Decis (non-IPM), Dimilin Flo, Insegar WG (non-IPM), Majestik, Runner (EAMUs required), Steward (EAMU 2008-2905), Toppel 100 (non-IPM) or Tracer (EAMU 2008-2908) if seen. Trichogramma parasitic wasps will target carnation tortrix and light-brown apple moth eggs.
Bacterial infections Apply a tank mix of Serenade ASO (EAMUs required), Cuprokylt and a wetting agent. Avoid rain and overhead irrigation for 24 hours afterwards to gain maximum product effect.
Sawfly Pests can appear in late April and they look like small, green caterpillars. They can defoliate crops such as aquilegia and robinia in a matter of hours. If you see any foliage damage, spray outdoor crops with Decis or Tracer (EAMU 2008-2908) and indoor crops with Dimilin Flo or Pyrethrum 5EC.
Tarsonemid mites These are microscopic pests that feed on plants' growing tips, causing stunting, distortion and galls. On protected crops, apply preventive sprays of Apollo 50SC (EAMU 2001-2271) or Dynamec. Amblyseius cucumeris and Amblyseius andersoni will feed on these pests at this time of year. Check soft new growth on asters, azaleas, cyclamen and Fatsia. These mites can also attack ornamental trees and shrubs.
Whitefly Apply Encarsia and Eretmocerus. If adults are seen, predators will struggle to provide decent control. Hang cards away from direct sun and irrigation.