Powdery mildew Adding a wetting agent to mixes (check labels first, not with emulsifiable concentrate types) helps to control disease attacks.
Pinus Check for weeping around buds, drooping stem leaders and stunted growth - a sign of pine shoot moth grub activity. Control larvae using Decis, Dursban WG or Toppel 100 (EAMU 2013-2410).
Spider mites Sequel, Masai, Dynamec and SB Plant Invigorator are useful products at this time of year. Predators are still effective on vulnerable crops. Naturalis-L will provide good knock-down control in tunnels and glasshouses with at least 60 per cent humidity.
Bed watering Automatic irrigation systems can have an uneven output so check crops along bed edges and pathways for drought. Keep different compost types and pot sizes separate. Start an irrigation efficiency drive, with water shortages looming.
Leatherjackets Pests are present in sand beds. Some will migrate into pots, causing similar damage to that of vine weevil larvae. Treat sand with nematodes or apply methiocarb-based products, which have an end use date of 19 September 2015.
Moths Check vulnerable crops including acer, ash, birch, choisya, Crataegus, Euonymus, Malus, oak and Prunus. Install pheromone lures attached to Delta traps to identify species for timely sprays of DiPel DF.
Hedge cutting The 31 July deadline has now passed.
Scab Check Pyrus, Sorbus, Crataegus, Malus, pyracantha and Chaenomeles. Monitor scab risk by using the Mills or Smith tables, which use weather conditions to calculate optimum spraying times. See feature, p23.
Adult vine weevil Control feeding adults by spraying Chess WG, products containing chlorpyrifos, Hallmark WZT (EAMU 2008-2944) or Steward onto the foliage of vulnerable ornamentals.
Fruit Remove all fruit from trees before despatch if a "non-edible" spray programme has been used this season.
Acanthus Control bacterial infections in acanthus crowns using Cuprokylt (EAMU 2015-1176) and Serenade ASO (EAMUs required).
Root aphid Control in pines and ornamental Ribes with Dursban WG.
John Adlam, Managing director, Dove Associates