By Brooklyn Botanic Garden. A common-sense approach to plant disease prevention
Keyword: Plant diseases--Control
Invasive and Exotic Species of North America – Images
A photo database of invasive plants, plant diseases and harmful insects, plus biological control agents providing “an accessible and easily used archive of high quality images…with an emphasis on educational applications.” Images are available to download for non-profit and educational purposes.
Garden Tip #395
Wondering when is it necessary to clean or sterilize your pruning tools, and how to do it? Washington State University Extension horticulturist Linda Chalker-Scott offers excellent “how-to” advice. Make sure there is no excess dirt or debris on your pruners before you clean them. There are quite a few impractical or inadvisable methods (formalin? chlorine bleach? no!); her preference is to use ordinary household cleaners.
Another factsheet discusses when to sterilize your tools. Chalker-Scott says that first you must know which pathogen is causing the disease. Then,
- “if it’s a virus or viroid, disinfect your tools.
- if it’s a vascular fungus or bacteria, and/or forms oozing cankers, disinfect your tools. Avoid cutting active, oozing cankers; wait until they dry.
- if you are pruning irreplaceable plants, disinfect your tools.
- choose a disinfectant treatment that has been shown to be effective through published research; I would probably not use alcohol but one of the common household cleaners at full strength.”
Garden Tip #122
By November Seattle has usually had a good hard frost and most of our herbaceous (non-woody) perennials have either turned to mush or look a bit tattered. Before you give in to the temptation to cut back everything in sight, consider the advice of natural gardening advocates James Van Sweden, author of Gardening with Nature (Random House, 1997) and Jackie Bennett, author of The Wildlife Garden (David & Charles, 1993):
- Leaving seed heads and dead stems over the winter gives the garden winter interest, especially if we get some snow
- Seed heads from Black Eyed Susans, Echinacea, Larkspur and Evening primrose provide bird food
- Beneficial insects hibernate or over-winter as eggs on plant waste
- Marginally hardy plants like some salvias and lavenders benefit from the little bit of frost protection from the desiccated stems
On the other hand, sanitation is critical if your apples suffered from codling moth or scab or your roses suffered from black spot. Rake up and dispose of every single diseased leaf or infected fruit. Insect and disease organisms also over-winter on plant debris, so if you had a problem this year, start the treatment now with a thorough clean-up.