Early this fall, I spread composted cow manure on my lawn and then seeded. The grass is doing well, but there are some weeds which my Extension Service identified as Wild Mustard, Yellow Rocket (Yellow Cress), and Penny Cress, all annuals. I assume the seeds were in the compost or in the topsoil I used in some areas. Pictures of the weeds show them at maturity with stems that hold the flowers and seeds. However, my weeds never grew to that point because of mowing. Only the low lying leaves exist. Not wanting to stress the new grass, I didn't apply weed killer.

I assume that being annuals that didn't go to seed, that these weeds will not appear next spring, so I will not need to use a preemergent on the lawn. I would prefer not to use a preemergent, in spring, as I want to dormant seed some thin spots late in winter.

Thanks for any advice.