Herbs Against Mosquitoes and Cockroaches

Can you let me know what plants/herbs I can grow that will kill cockroaches and mosquitoes.

We are not aware of any herbs that will kill these pests, but there are some known to repel them. We have answered questions about mosquito repellent herbs several times previously; go to the "Q and A" section of our website and search for "mosquito" and past articles will come up.
Bay leaves are reported to repel cockroaches. For effective control, however, diatomaceous earth works well. You dust the areas where the pests are known to frequent and within days the problem usually clears up. Richters sells 'Fossil Dust' which is made with diatomaceous earth.