By early spring, its quite normal for small weeds to be germinating, and for moss or algae to be present on the surface. The latter indicates soil which is usually fairly heavy, and which has not been cultivated for some months. Dig the bed over, removing the weed seedlings as you go, and without digging up your plants. If you leave doing it till mid March, you can add a fertiliser at the same time, something like Vitax Q4 or Growmore - if waiting that long means the weeds are excessive, hoe them off now and dig in a couple of weeks.

Do not think of using Jeyes fluid, this will kill of all your plants.

After weeding as bamboo says, you could also dig in soil improver such as spent mushroom compost. but as MG says jeyes will kill your plants too so not a good idea.

If your plant begins to have spots on it this year post a photo on here and somebody will probably be able to tell what it is and what to do.