Experts and BHG readers answer.
Seeds sowed in a small container covered with plastic
These 3 types of plants are slow and somewhat difficult to germinate. Peonies can take months, and may need a cold treatment in order to germinate. It might be a good idea to learn more about seed germination techniques with easy-to-grow types first. Marigold and zinnia are some of the easiest.
Even though you covered the seed starting mix after you watered it, the compost may have dried enough that the seeds wouldn't germinate well. It pays to check for adequate moisture on a daily basis. Also, what temperature did you keep the seeds at? Most types of seeds germinate well at about 70 degrees F. If it's too cold or too hot, they may not grow at all.