Grass weed control - Apply Aramo (EAMU 2015-0454) over outdoor ornamental crops to control annual meadow grass. Although many crops are tolerant of this herbicide, AHDB members can check crops before spraying using the AHDB Horticulture weed handbook.
Leaf spots - Apply Octave, Rovral WG (2011-3200), Signum (EAMU 2012-2141) or Switch to protected crops vulnerable to fungal leaf spots. Diseases can overwinter on evergreens, plant debris and dead leaves hanging on deciduous crops.
Light - Pull back thermal screens and wash off shade material from glasshouses to take advantage of sunny days.
Virus - If there are a few plants showing mottling within a crop, remove and destroy them to prevent infections spreading from cultural work such as trimming. Burn the affected plant material (using the appropriate waste exemption) rather than composting it.
Hydrangeas - Remember to expose crops to the first frosts to promote flower bud initiation.
Powdery mildew - This disease produces winter resting spores so use contact-acting eradicant fungicides, which are more effective now. Use food-grade potassium bicarbonate, Signum (EAMU 2012-2141), Switch or Takumi SC (EAMU 2013-1294).
Slugs - Apply commercially approved slug pellets to vulnerable plants especially during periods of wet weather.
Phoma - Apply a final spray to affected ceanothus, viburnum and vinca using Octave, Signum (EAMU 2012-2141) or Switch.
Biocontrol - Where predator applications are still being made to protected crops and no clean-up sprays have been applied, gap-up plants to help predators move through crops.
Heaters - Winter-grade oil should be put in heaters especially if diesel oil (35 second) is being used, to prevent fuel gelling. Premium-grade paraffin in direct-fired paraffin heaters (28 second) will help prevent leaf scorch from combustion. Clean out fuel filters if you have had a biofuel content in your oil.
Green compost - Applying PAS 100 green compost as a mulch or incorporating it into soils has multiple benefits including disease suppression and moisture retention. To find your nearest supplier, go to www.quality compost.org.uk/producers.
HorticultureWeek.co.uk/nursery.
