Volunteer members are currently weeding and performing a clean up operation at our current nursery site.
We are treating the nematode issue as prescribed by the AHS by removing infected leaves and isolating the infected plants.
Unfortunately this is not a one step or immediate cure and will require several seasons of treatment. Care needs to be taken in using chemicals that might prove toxic to the
The options for treatment require an understanding of the life cycle of the foliar nematode. Research indicates various methods for treatment and we will continue to explore options that are both environmentally safe and effective in curbing the spread of the infection.
It should be understood that there is no known cure-all for eradicating these pests.
See the recent issue of the Hosta Journal for a comprehensive report on the progress and methods for treating nematodes. (2014, Volume 45, Number 1, PP.68-77)
The DHSWP understands its responsibility not to vend any hostas that might have visible signs of nematode damage.
During the period in which our plant material is being treated at the nursery it will become necessary to buy hostas from other sources. Purchasing TC or tissue culture plants virtually guarantees nematode free plants.
Arrangements are being made to purchase retail ready plants this fall that will be ready for marketing as early as the Hosta Show in June of 2015.
The sale of these plants will ensure a continual flow of revenue to sustain our success as a society committed to the education of the genus hosta.
It is imperative that we educate ourselves to recognize and treat foliar nematodes.
Photos of the infection are available at the AHS website…hosta.org.
Chemical sprays or systemic treatments that are available to the nursery or greenhouse owner are not readily available to the home gardener.
It should also be noted that treatments and available pesticides are being tested and the AHS has heeded the need to address this problem ASAP.
What Can You Do to Prevent the Spread of Nematodes???
Once identified you can remove the infected leaves or the entire plant (depending on the extent of damage) and place the damaged leaves in black plastic bags to be discarded. DO NOT compost!
Remove the infected plant and place in an isolated area down hill and away from healthy specimens.
As you cut and remove damaged leaves you can periodically treat your pruners by dipping them into a solution of 10% bleach to prevent any further infection.
If you are looking for a miracle cure, there isn’t any! Using certain pesticides poses a biological risk to you and the environment so be careful to read the label prior to using.
At the same time it should be noted that nematodes DO NOT kill the plant. The nematodes enter the leaf creating brown lesions between the veins making the leaf appear to be striped. Their presence is only noticeable in late summer into fall. If HVX (Hosta Virus X) can be thought of as a cancer, then nematodes could be likened to a skin disease.
A few products that were effective in treating nematodes have been lifted by the government due to harmful side effects to living things ( that includes us also). Some folks are experimenting with various products and claim to be getting some relief from the nematodes.
The DHSWP is not recommending the use of any available products at this time until more results can be obtained through carefully managed research. We sincerely hope that some viable solutions are forthcoming.