Our general landscaping plan is rather informal and uses almost exclusively perennials as you can see in the after photo of the back yard. The area north and east of the house is slightly higher than the house so large amounts of water would pool in the back yard and the north side of the house in the wet Seattle winters. We had to install over 600 feet of french drain across the back yard and around the south side of the shop to divert the water around the house.