Those trees are humungous. You need to trim them and keep them trimmed. I am not a garden expert, but they are bordering on being a danger. If you want to keep them hire a tree expert to come out and come up with a solution.

Trees can't just be planted anywhere in the landscape, and one of the primary reasons is that their roots don't always play nicely with other below-ground or surface elements.

In fact, over time, aggressive root systems can cause serious damage to landscape structures and utilities, most importantly our homes.

Here are a few common northern trees with particularly invasive or aggressive root systems: Silver Maple (Acer saccharinum) - shallow and dense roots, plant well away from homes and forget about planting any gardens nearby!

Appears that the dilemma is do I want to provide shade for my visitors or is my priority to take them out and save my lawn and my back in the fall?

I would hesitate before removing both trees knowing how hot and dry it gets in your part of the world. I would consider a compromise and remove the one in the area that still has the grass intact. That way you have one area of deep shade and another more open area. Talk with a local nursery, master gardener or garden designer about attractive well behaved small trees or shrubs that work well in your area to replace the tree and convert that area to a xeriscaped garden including native plants, bulbs, rocks and ground cover plants or mulch.

Meanwhile back to the original maple tree: native ferns do well in dry shade, early bulbs that flower before the tree leafs out would also be an option. Again, a local garden expert can give you tailored advice for dry shade plants in your area. All those maple leaves are a gold mine for mulching! If you bag them up, and water them well in the bags, stash them somewhere out of sight for the winter, by spring you will have nicely rotted leaf mulch.

Not a landscaping pro but this worked for me:

If you want to the roots to not grow/crawl around on top of the ground, they need seek/find water below ground.

When there is little rainfall, the ground does not get wet deep and roots seek water where it is -- near the surface.

The roots of trees feed about the same distance from the trees where its limbs reach.

You could try digging long a ditch about two feet wide and two feet deep near that point where the roots will feed and creating the equivalent of a septic tank drain field (gravel filled in to within a few inches of the top of the ditch w/pipe that has holes in the bottom of it just barely covered in gravel.

Add some of the black flexible pipe to your nearest gutter downspout, burying it just below the ground and connecting it to the drain field pipe. Cover the pipe from the downspout and the drain field with several inches of dirt.

Adding a layer of roofing paper over the pipe and gravel will make it less likely the dirt above the pipe will wash down into the gravel and fill in the pipe holes with dirt.

The rain or any water you pour into the gutter will water your trees below ground and the roots will seek out that water -- not just stay near the surface.

Here's a few local sources for plant choices in your area:

http://okanaganxeriscape.org/plant-database

http://nativeplants.evergreen.ca/lists/view-list.php?list_ID=00164

http://www.laughingswanfarm.com/perennials.php

http://www.canadiangardening.com/plants/perennials/15-perennials-for-dry-shade/a/56836

Oh, just noticed that you were cutting off the thread, too bad! I think that the work you have done so far is great. Getting rid of lawns and replacing it with mulch like you are doing is a good idea. Were you looking more for creative design ideas? I like to look at natural areas for inspiration (camera helps) and then try to integrate those into the city/suburban garden so as to blend the transition from the wild into the "edge of the wild" mixing native with hardy garden perennials, shrubs etc.

Good advice above re. dealing with roots, also piling on the mulch and leaf mould really helps as well. Happy gardening!

PS Re the leaves: we leave our grass a little long for the last cut of the year, if you have a grass catcher, just mow over the grass and leaves and it will act like a vacuum cleaner and you will have even more organic matter for your mulch collection.

That is your garden? Look great! To deal with hardpan you are more likely to get improvement by layering humous on top rather than more soil. There is a lot of interesting new information around amending soils with micorrhizal fungus, aerated compost teas etc. The old school advice was to double dig or till which usually makes things worse. It's a little technical but this article has some good info re improving soils. http://ohioline.osu.edu/sag-fact/pdf/0010.pdf

I like the idea of a native garden that was mentioned by Trim Spaces.

I think that your original post should have been more specific, it said we want to keep the trees.

When someone mentioned something about cutting or triming or removing , there is a sense of unfriendliness from you. Then you say, we were thinking of getting rid of one of the trees.......You should have said this initially, as well as sharing your drawings.

You know this is a difficult dilemma and the advice is free, and Houzzers want to help, but share your information - so that we can.

You had mentioned you were from BC, I am sure there are native plants from your area that would look good combined with the tree. You had mentioned that you have already removed the grass from the area, why don't you try a small garden and see what it looks like. I would never remove the tree myself. I hope this helps..

I would build a stone retaining wall about level with the rest of your lawn and fill it and then add a nice dark mulch. Not an expensive job and will make your home really stick out!

Also, what roof do you have?

The silver maples are native trees, and you'll see in nature that the ground under them is almost completely bare. They have shallow roots, and kill most stuff above them, even other native plants.

And if you add soil over the roots and try to grow stuff in it, it will damage the tree. Those roots are meant to be on the surface. You might get a few ground covers to grow, but it's hard on them. Try ajuga (bugleweed) or golden creeping jenny. Or just mulch it and it will look fine. If you want to add interest, large pots are the way to go.

Here's a link to a discussion link

Cheer up. At least you know you can grow junipers. Or whatever it is. I am in California, USA. Like you, I am restricted in what I can grow due to the shade. It seems that a lot of xeriscape type plants need sun. I expect if will be harder even for you, due to your winters. Boxwood is is a low water plant. Mine grows in filtered shade. Like you I have a tree blocking the sun but the tree does not have a dense canopy. Some boxwood can take zone 4. I will probably end up planting more just because I know it can live.

Very interesting, all these suggestions and what you have done. Any updates on how the project is doing two years later?!