From the nursery

Needle cast You should have sprayed Picea, pines, Abies and Thuja for spring needle cast diseases. This week use Bravo 500, Dithane 945, Cercobin WG (SOLA 2008-1384), Signum (SOLA 2009-1842) or Switch.

Trimming If you normally trim your shrubs at potting this late in the year, consider a change of procedure. I believe that you should not allow a newly trimmed plant to be dormant for a long period afterwards. Either trim a few weeks before potting, while there is still some growth, or wait until early spring so the plant will start growing soon afterwards.

Vine weevil The lower-temperature nematodes provide good vine weevil larval control at this time of year. Make applications to protected crops, particularly those exposed to egg-laying that do not have any other protection. I find that nematodes are more effective than drench applications on large trees that have vine weevil. You can apply nematodes until we get heavy frosts that reduce the growing media temperature.

Botrytis I know I mentioned it last month but still watch out for Botrytis on a wide range of pot-thick container plants and spray where seen. Crops most at risk are those closely spaced and those with very hairy foliage. Keep the tunnel or glasshouse doors/vents open whenever the weather allows, to aid ventilation. Horticultural Development Company work showed that at between 10 degsC and 20 degsC and a humidity of 100 per cent, Botrytis growth is irreversible after three hours. If you can introduce air movement within the crop canopy and not just over the crop, the incidence of Botrytis is dramatically reduced. If you have automatic watering, alter the sequence by watering those susceptible species early in the morning rather than late at night. The foliage will dry out in the morning rather than stay wet all night. Aim to have the leaf surface dry at least once every 24 hours.

Western flower thrips It is worth continuing your Amblyseius introductions throughout the winter on crops in a frost-free structure. While they are not highly active, they do still find thrips to feed on and you will get a lower overwintering population resulting in fewer early-season infestations, especially if it is used with Nemolt (SOLA 2007-2120).

Hard water Spraying with hard water can reduce the efficacy of pesticides. Add products like the foliar feed Poliverdol, which will considerably improve the product efficiency.


Have you registered with us yet?

Register now to enjoy more articles and free email bulletins

Sign up now
Already registered?
Sign in

Before commenting please read our rules for commenting on articles.

If you see a comment you find offensive, you can flag it as inappropriate. In the top right-hand corner of an individual comment, you will see 'flag as inappropriate'. Clicking this prompts us to review the comment. For further information see our rules for commenting on articles.

comments powered by Disqus

Read These Next

Tomorrow's tractors

Tomorrow's tractors

These machines have advanced rapidly over recent years but what does the future hold? Sally Drury looks ahead.

Climbing roses

Climbing roses

Walls, trellises, pergolas and even trees can all be brightened up by these beautiful blooms, writes Miranda Kimberley.

Pest & Disease Factsheet - Mealybugs

Pest & Disease Factsheet - Mealybugs

Vines, tomatoes and tropical plants are among those at risk.

Opinion... Shining a light on trading with Europe

Opinion... Shining a light on trading with Europe

Accurate figures are notoriously difficult to get at, but without doubt the UK imports a great deal of its ornamental plant requirement.

Opinion... Unbeatable delight of quality plants

Opinion... Unbeatable delight of quality plants

Viewing top-quality plants, both growing and on sale, always gives me pleasure.

Editorial ... More analysis and insight from bumper HW issue

Editorial ... More analysis and insight from bumper HW issue

Welcome to this bumper 72-page July edition of Horticulture Week magazine, packed with exclusive analysis, insight and expert advice on the biggest issues impacting all sectors of the UK horticulture industry right now.

Follow us on:
  • Facebook
  • LinkedIn
  • Twitter
  • Google +
Horticulture Jobs
More Horticulture Jobs

Tim Edwards

Boningales Nursery chairman Tim Edwards on the business of ornamentals production

Read Tim Edwards

Ornamentals ranking

Top 30 Ornamentals Nurseries by Turnover 2017

Top 30 Ornamentals Nurseries by Turnover 2017

Tough retail pricing policies and Brexit opportunities drive the top 30 growth strategies.

Pest & Disease Tracker bulletin 

The latest pest and disease alerts, how to treat them, plus EAMU updates, sent direct to your inbox.

Sign up here

Are you a landscape supplier?

Horticulture Week Landscape Project Leads

If so, you should be receiving our new service for Horticulture Week subscribers delivering landscape project leads from live, approved, planning applications across the UK.

Peter Seabrook

Inspiration and insight from travels around the horticultural world

Read more Peter Seabrook articles