Tortrix moths: Adults are still egg laying at the moment so be alert. Spray with Decis or Toppel 100EC in non-IPM systems. IPM-friendly products include Conserve, Dimilin Flo, Insegar WG, Majestik, Nemolt (SOLA 2007-2120) and Runner (SOLA 2008-2903).
Serenade ASO: This product is working well at keeping shot-hole at bay. Although we have had a dry spell of late, when we have had rain there has not been much bacterial damage to laurels treated with it. It can be mixed with Croptex Fungex or Cuprokylt. Consider adding in a siloxane wetter such as Silwet L-77 or Slippa rather than Codacide Oil. These products achieve a better spread of Serenade ASO over shiny leaves for better control during wet spells.
Irises: Insect root damage on irises, bringing with it fungal rotting, will be active any time now. Drench the soil or compost with Intercept 70WG to control burrowing larvae that cause corm soft rot.
Setting red berries: If you have any Berelex tablets left then use them to achieve flower set by getting the right male/female combinations. This product will 'set' the flowers now emerging and allow maximum berry retention for this autumn. Apply to Ilex, Viburnum and Cotoneaster.
Water storage: Take a critical look at your irrigation system and check if your storage capacity is adequate. Have at least 24 hours' supply in case of interrupted water from mains water companies. Reservoirs are cost effective if you have the space for them but to hold all the water for a year's supply for one hectare of container beds needs around 3,000sq m of land and could cost £12,000 to build. Giant tanks are available up to 3m high and 20m in diameter, holding up to two months' supply for one hectare of container beds. Always build tanks outside glasshouses to avoid Legionnaires disease through warm water.
Box blight: This disease is still active so spray Buxus subjects with Scotts Octave, Cercobin WG (SOLA 2008-1384)m, Signum (SOLA 2009-1842) or Switch.
Shading: Consider moving yellow-foliaged plants under shade to avoid leaf scorch or fading of the foliage.
- John Adlam is managing director at Dove Associates www.HorticultureWeek.co.uk/nursery for recent articles