Training Center


Pre-Plant and Planting Tips on Minimizing Root Diseases

Root diseases can lead to considerable losses in crops, increased fungicide applications and reduced crop quality. There are several useful tips that, when followed, will help improve the growing environment to reduce potential root disease outbreaks.

By following these tips below, not only will there be fewer root disease issues, but a better growing environment will contribute to improved crop quality.

Pre-planting Tips

  • Remove all plant debris, weeds and growing medium from the greenhouse as they harbor root diseases.
  • If possible, cover soil floors with landscape fabric or concrete to minimize fungal spore movement from the soil into the greenhouse environment.
  • Disinfect tools that come in contact with plants.
  • Disinfect potting benches, potting machines and flat fillers to kill disease inoculum.
  • Avoid reusing pots. If they must be reused, soak in a product containing quaternary ammonium, hydrogen dioxide, hydrogen peroxide or peroxyacetic acid compounds, or use bleach to kill pathogens. Remove all growing medium from the pots first and soak for at least 30 minutes or as the label instructs. Change the solution often.
  • Discard old plants that did not sell as they may harbor root disease pathogens.
  • Verify that stock plants are disease-free before introducing a new crop into the greenhouse.
  • Do not reuse the growing medium as it may be contaminated, which could explain why some plants looked poor and did not sell.

PRO-MIX Cardamine and Oxalis Under Bench Norcella

All diseased plants should be removed from the greenhouse to minimize disease spread. Empty pots from a crop with root disease should not be reused as the pathogens can persist in the container and infect future crops. Source: Premier Tech

PRO-MIX Blooming Acres - dahliettes dying

All weeds and plant debris should be removed from under benches and walkways to minimize reservoirs for plant diseases. Source: Premier Tech

Planting Tips

  • Use resistant plant varieties or those that are less likely to become infected by a root rot pathogen. Remember compact, slower growing cultivars typically have more root disease problems than faster growing cultivars due to lower water usage.
  • Use disease-free, culture-indexed cuttings. Also, if you order seed and/or bulbs, verify that they have been disinfected by the supplier.
  • When taking cuttings, dip cutting tools into a sanitizing solution before going to the next stock plant in order to minimize the transfer of pathogens.
  • Quarantine and inspect incoming cuttings, plugs or other plants to verify there are no diseases. If there are, treat with the appropriate fungicide. Biofungicides do not cure an existing root disease problem.
  • When filling planting hoppers or containers, any growing medium that falls on the floor should be discarded as the floor often has pathogens.
  • Do not compact the growing medium in containers as this reduces air space causing plant stress, uneven drying and increased susceptibility to root diseases.
  • Use a well draining growing medium with a biofungicide for susceptible crops. PRO-MIX HP BIOFUNGICIDE* + MYCORRHIZAE would be ideal.

*All BIOFUNGICIDE products are available under the designation BIOSTIMULANT in Canada and Latin America.

If you have further questions, please contact your Premier Tech Grower Services Representative or your Regional Sales Representative.

PRO-MIX® is a registered trademark of PREMIER HORTICULTURE Ltd.

Related Articles

Your 2021 season full package

Get full access to all the information you need to start the season on the right foot.