Good advice above re cutting back the tall tree and choosing replacements. I'm in the mid-Atlantic region, so wouldn't venture to suggest plants for your region. I would, however, suggest that you think carefully about the river rock. Many people have rued the day they installed it, or purchased a home with it in the landscape. It's a huge project to remove. Organic matter will collect among the stones, where weed seeds will germinate and grow. The stones collect and radiate the sun's heat, leading to a warmer & dryer soil, whereas an organic mulch like shredded wood will lead to conditions more like those on a forest floor - cool and moist - and will eventually decompose and improve soil structure and bio-activity. If the stones are light in color, they will also reflect the sun's light back up to the undersides of the leaves (an unnatural situation) and, according to some sources, increase certain pest activity.

If you are considering the river rock as a way to brighten that northern exposure, instead consider some plants with variegated green and white foliage. These really pop in the shade. Chartreuse also works very well for this purpose, but I'm not sure how it would look with the colors of your house.

Thank you both for the advise! I'm definitely leaning more towards removing the tall cedar and replacing it, since we ordered a whole bunch to do a privacy hedge in the back yard. My hesitation now is how to actually remove it. I'm sure the tree has been there for a long time and the roots are well established. So how do I remove it without killing the other two short cedars about 2 feet away from it? And also make enough room for a new tree? sorry I'm a complete novice in this. I'm afraid to start...

And thank you for the input about the river rocks! The front of the house faces North so it's not in the full sun. So I think I'm good.

I would remove the top growth of the tree with a saw, and then tackle the roots, digging out as many as you can. A couple of friends with strong backs will help! The other plants should be OK...just work around them.

Thanks! I ended up keeping the tall cedar and trimmed down the top a bit. It looks okay. Before putting new plants in, how should a prepare the soil so it's health for the existing cedars and for the new plants? I'm leaning towards a few Japanese skimmias and some heathers to line the edge.

Heathers and skimmia both like an acidic soil, but skimmia requires some shade (some morning sun and afternoon shade is best) while heathers require plenty of sunlight or growth and flowering will be sparse. Check out heath - it's similar in habit to heather, and still prefers full sun, but is a bit more adaptable to less-than-ideal conditions.

The best thing you can do is to add compost...homemade or purchased.

Update: Thank you everyone that give me tips and advise! The front garden is done now. I couldn't have done it without your guidance. Thanks again!!!!

I just happened upon your post and don't know if you'll see this, but your house is the cutest, EVER!

Can you rent a stump grinder? That would be the way to go! Cut down the tree, haul it off, then grind the stump (instant mulch).!