We have thousands of carpenter ants in our flower gardens, vegetable garden and in our grass. We don’t have the money to have someone take care of the problem for us. How do we get rid of so many ants? They are all over everything. We would like to keep it natural because of the birds and other animals but at this point we will try anything. We also have some plants, especially roses, that look like they are dying from the ground up. Is this due to the ants or do we also have another problem?
Your roses are likely affected by aphids (or other sap sucking pest), which secrete sweet honeydew. This is what attracts the ants, so really getting rid of the aphids will in turn get rid of the ants as well. Neem oil is the most effective pesticide and is safe to use on all types of plants, including edible ones. Here is additional information: https://www.gardeningknowhow.com/problems/pests/neem-oil-uses.htm