” My front lawn has been reseeded recently and is not growing properly, could this be due to too much rain or lack of sunlight? could the soil be too compact? I don’t notice any worm casts, so I thought about introducing earthworms into the soil. “
This is not a question simply answered, a lot depends on what the soil was like prior to planting the seed, assuming the soil is up to supporting the growth of grass seed (it would have to be pretty poor not to do so!) and has been prepared properly then you have to look at the conditions, too cold, too wet, too hot and too dry will affect the germination rate, if the light levels are pretty poor such as in a heavily shaded area or under trees then germination could be slow and patchy, add to this that birds may have been feasting then you may have problems, lack of worms at this point will not affect the germination rate so until any problems have been put right it is unlikely that adding earthworms will help much to get things going.
The adding of earthworms to gardens is not something that is readily thought about, unfortunately it is often considered after a lot of work has already been done, adding earthworms should be planned in at a very early stage, taking the lawn as an example, even before adding worms the conditions they need should be carefully prepared, contrary to beliefs worms do need quite a good soil to live in, if the soil is hard, compacted, sandy, very dry etc worms will not suddenly turn it into good soil, they will leave! when the soil is good worms will work and turn this good soil into excellent soil and all plants, including grass will benefit from this. The action of worms in the soil creates burrows where oxygen and water get into the soil around the plants roots, when a worm feeds it leaves behind worm casts, sometimes these are left on the surface, these casts are a bundle of goodness, not necessarily fertilizers but all the other things that plants need to thrive, all this has to be in place before seeding, so the answer to the question “Should worms be in a lawn” is certainly yes! (as long as you don’t mind a few casts on the surface)