Deer resistant is tough when it comes to rain garden plants. Here are some that work for me: columbine, blue stemmed goldenrod, some grasses, witch hazel (some browsing but so far OK) bayberry, red cedar, wild geraniums like geranium macrorrhizum, wood fern, bleeding hearts. Milkweed are a deer favorite munchie!

Percolation test results 18" deep hole held approximately 10 gallons of water when full. Two trials, both required 8 hours to drain. Drainage area Neighboring roof is approximately 60' wide and 77' deep, netting a surface area of 4620 square feet. To check: if all of the roof runoff drains to the north side of the building or if a portion drains to other sides. Rain garden area 20% of 4620 square feet = 924 square feet A 115' long garden 8' wide would suffice. Or a 77' long garden running the length of the building would require an average width of 12'. (Based on the idea that all of the water drains to this area.) Although this seems large, in times of large amounts of rainfall, this area floods, runs under the fence, and produces a 1' deep pool covering 3-4 parking spots in the apartment building's parking lot.

The other area I think would be the front yard just beyond my porch. There are wooden flower boxes and next to the downspout is a wood flower box as well. The storm water overwhelms the cement porch and gets trapped because of the wood boxes and just stands causing damage to the posts that support the overhang.

I love both the plants you selected, but I can tell you they won't grow in sun. Ask me how I know . . . You might be able to find a white lobelia (the perennial kind) or a white penstemon (Beard's Tongue) that has a similar shaped flower. Some of the paler gentians can take a bit more sun than turtlehead. Two plants with somewhat "ferny" foliage are Golden Alexander, Zizia aurea, and Comptonia peregrina, my favorite, called "Sweetfern." Hard to come by but not hard to grow, you can find it at the better native plant nurseries. It won't take standing water for long periods, but it can take wet then dry, which is the common condition of a rain garden. Both plants will not like shade on the flip side. Again, ask me how I know . . . :)