So. Cal. Gardeners (or others who plant in Fall for Spring bloom) what can I do about this problem. (Details inside).

I am a novice gardner and this is the first year I will have started a Spring garden from seeds and transplants. I’m attempting to create a perennial flower garden so I have a lot of stuff in the ground. I began planting seeds and bulbs in the early fall and am getting ready to put in my hyacinth.

Trouble is grass and random flowers/plants are springing up everywhere. I’m worried that these unwanted plants are going to overrun the seeds and young transplants. I don’t want to end up with a bunch of grass and flowers everywhere. I have a specific, plotted design. However, if I just pull out the unwanted foliage I’m worried I might somehow do damage to seeds and transplants that are trying to take root.

Am I worried for nothing? Will my plants root and will the grass/plants just die? If there is something I can do to get rid of the unwanted plants/grass without damaging my flowers?