My dogs are digging up grub worms every day Can I spray nematodes at this time of the year?
Late summer and early fall are the best time to treat for Grubs.
These articles have information on Grub control.
https://www.gardeningknowhow.com/plant-problems/pests/insects/get-rid-of-grub-worms.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/what-is-milky-spore.htm
How do you get rid of Voles?
Here is an article that will help you.
https://www.gardeningknowhow.com/plant-problems/pests/animals/vole-control.htm
Question: What is this condition? What is causing it and how do I fix the problem? There seems to be a black material at the stem of each leaf.
You may have a few issues on your plants.
The black on the leaves is likely Sooty Mold. This is the residue from pests.
You may also have fungus disease that could be caused by excess moisture or poorly draining soil.
Treat the plants with Neem Oil, Neem Oil works as both an insecticide and fungicide.
Correct the watering if needed.
https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/what-is-well-drained-garden-soil.htm
We have a rubber mat about 50 ft. long under our back deck where we store our tools. It stays there all of the time, so there is no grass growing under it. I pulled it up yesterday and found holes about the size of a quarter from one end to the other. Probably 75-100 holes. There are no mounds around them because of the mat covering them. We live in the country and our house is surrounded by trees. I know that we have rabbits, squirrels, raccoons and o'possums. I see a snake every once-in-a-while, but not very often. What do you suppose is causing these holes? Should I be concerned and what do I do about them?
If the holes extend down into tunnels, they could be vole holes, especially the pine vole. They are not dangerous but will eat garden plants from below the ground, so if you have voles, you would most likely see damage to any vegetables you are growing. Chipmunks can make similar holes, but I'm not sure if they'd make them under a mat. Snake holes are another possibility, since they can also be about the size of a quarter.
Here are some ideas for snake control and vole control:
http://msue.anr.msu.edu/news/snakes_and_your_garden
https://www.gardeningknowhow.com/plant-problems/pests/animals/vole-control.htm
How to get rid of tinn worms?
I cannot find any information on a worm that goes by the name of tinn worm. Can you include a photo of them? There are ways to deter a broad range of pests from your garden that will work for many types of pests.
Neem oil can work in light concentration as a soil drench or spray. You can also boil sliced hot peppers in water, let this cool, strain, and spray onto the plants and soil. Rosemary oil can also work as a good deterrent as well.
how do I best kill cutworms
This article will help you.
https://www.gardeningknowhow.com/plant-problems/pests/insects/get-rid-cutworms.htm
What is an organic solution to get rid of pesky aphids in my greenhouse once and for all?!!!
I garden in MN also, and I have noticed quite a few Aphids in my perennials this spring!
This article will help you.
https://www.gardeningknowhow.com/plant-problems/pests/insects/homemade-aphid-control.htm