How do you know if your hostas have nematodes? Signs of nematode damage come to Wisconsin in later summer through fall. You will start to notice brown streaks in the hosta leaves that stay between veins. You can also cut up the leaf you believe is infected, place the cut up leaf in a glass of water, wait an hour or so, hold the glass up to the light, and look at it with a magnifying glass. If you see something swimming around in the glass, your plant has nematodes.
|Not best picture, but example of hosta infected with nematodes.
How can you get rid of nematodes? There is not a lot you can do, besides destroy the plant. There have been some experiments done, but nothing has been clear cut as to how to rid a plant of nematodes. One of the suggestions is to heat treat the plant. Submerged plants in water that is 124 degrees Fahrenheit for 10 minutes. Or you can just throw them in the washing machine like my friend Andrea did;) Another suggestion is to cut off all of the leaves and soak the plants in a 10% bleach treatment overnight. Just be aware that both of these treatments may kill your hosta. So while there are no 100% effective ways to get rid of nematodes, you can prevent the spread of nematodes by not watering plants from overhead and buying from reputable sellers.