It will work just fine, How much water does it get? You need to find a shade loving moss (prefferably from your area) that likes the moisture conditions you have and you can either transplant large sheets of it (with permission from the land owner) which can require denuding a large area or you can just pull off all of the vascular plants that you don't want to be there and put little clumps of moss down, spores will be caried in and the moss you put down will spread and you will have a lush carpet in about 3-5 years. Good luck.

Tandaina

Maples not only provide a lot of shade they also keep the ground underneath their canopy pretty dry. Any transplanted moss will need to be watered for one to two years till the transplanted moss gets established. You can use a 1 gallon pump sprayer with rainwater or distilled water or if you think your tapwater is not hard or contains a lot of dissolved salts you can use your tapwater.

Another problem with bare dirt under maples is that moss has nothing to grab onto. Fine soil particles like clay or loam are very small. Moss, not having roots only rudimentary anchoring structures, attaches to the soil particles and then when weather threatens the moss gets gets blown or washed away. Add some course sand on top, a thin one quarter inch layer will do it. This will help anchor the moss you transplant.

Brendan is right, moss is your best bet for groundcover under maples.

Rick

Thanks for the info. I'm on city water here so there isn't any minerals from a well to worry about. I water everything else with the tap water, hopefully it would work find for moss as well?

Yes, its definately dry and powdery under the maple. So a layer of sand and then water. Would a misting system like Moss Acres suggest be a good way to go? I'm afraid if I used something like a sprinkler I'd just create a muddy mess or was away the sand.

tandaina;

Misting systems are the best. With a misting system turned on once or twice a day for ten minutes you will greatly accelerate the growth of your moss. Moss can grow rapidly in hot weather if it gets enough moisture and not too much sun. Since ground under maples gets almost no sun I think you will find the misting systems and a little fert will go a long way.

Last year I put some moss on sand in a clay saucer near, but not right under, my dryer vent on the north side of my house in late June. The moss more than doubled in a month.

Rick

Moss will grow on mud so long as it is more dirt than water, In a few days I'll take a picture of a "terrarium" of mine that is really just a dirt bottomed aquarium that I emptied of water and moved outside, then added some moss bits too, its getting to be quite mossy inside.