I have a dahlia in my garden and I noticed a couple of stems have tiny black creatures on part of the stem.how do I get rid of them?
Tiny black creatures sound like aphids. You probably don't want to blast them with the hose; the force might break a stem. Insecticidal soap or neem oil should work well. If you don't think they are aphids, please write again with detailed description and exactly where they are on the plant. A picture works wonders. Here is more info on aphid control: https://www.pesticideresearch.com/site/pri-resource-centers/pest-mgmt/pest-mgmt-bulletins/aphid-control/