One of the easiest and most effective ways to help manage plant diseases is good fall cleanup of your yard and garden. Many common fungal and bacterial plant pathogens, particularly those that cause leaf diseases, survive Wisconsin winters in leaf litter from trees and shrubs, as well as on herbaceous plant parts that have died back for the winter. Disease-causing organisms can also survive on common gardening items like pots, stakes and tools. So, as the temperatures cool and plants begin to go dormant for the season, here are a couple of things to think about doing to put your gardens and landscape to bed for the winter and have a head start on your gardening for next year.
Rake up the leaves from your trees and shrubs, cut back herbaceous perennials, and remove dead vegetable plants and annual ornamentals. The safest way to dispose of these materials is typically to take them to a local yard waste center (if there is one available in your community) where they can be properly composted. If not, other options for disposing of this material include burning (not particularly environmentally friendly, but an option if allowed by local ordinance), burying (make sure the material is completely covered by approximately two inches of soil) or hot composting. Note that for some diseases (e.g., late blight, white mold, Southern blight), burying or home composting may not be good options. Therefore, if you are uncertain how to dispose of debris from plants that have had specific diseases, feel free to contact the Plant Disease Diagnostics Clinic at (608) 262-2863 or firstname.lastname@example.org for advice.
Decontaminate other items from your garden. For clay or ceramic pots, wash the pots well with soapy water (to remove any remaining soil), then soak them for 30 minutes in a 10% bleach solution. Rinse your pots well to remove bleach residues, allow them to air dry, then store them in a clean location where they will not be recontaminated. Decontamination of plastic pots (or other plastic items like stakes) is often more challenging. Often bleaching will not be effective and your best option may be to throw out plastic items and buy new ones next year. Decontaminate gardening tools by dipping them for a minimum of 30 seconds in 70% alcohol (e.g., rubbing alcohol) or spraying them until they drip with a spray disinfectant that contains approximately 70% alcohol. As with decontaminated pots, store clean tools in a location where they will not be recontaminated.
To learn more about common diseases and disease management, explore the Plant Disease Diagnostics Clinic (PDDC) website (https://pddc.wisc.edu/) and in particular, check out the University of Wisconsin Garden Facts fact sheets that can be found there. Also, follow the PDDC on Facebook and Twitter @UWPDDC to receive updates on emerging diseases and their management.