You need to make a rain garden and move your current flower beds away from the roof runoff areas. A few pots -- or even a lot of pots -- can't effectively deal with roof runoff, expecially from the kind of storms & heavy rains we get on the coast. The longer you delay, the more erosion and related problems you'll have. I live near Wilmington NC and rain gardens are really catching on here. Fortunately, they are simple to make! Here is a link that might be useful: instructions for making a rain garden

If you have a yard out back that slopes away from the patio, consider installing dry well(s) to carry the water away and dump it in the back yard at an elevation that is lower than the patio. Scout you problem area and decide where you want to place the collection well(s). You could create a minor depression that is lower than the surroundings. What I propose does require some digging. Basically, a dry well will be buried flush to the ground, water will run into it, and near the bottom of this well, a drainage tube will be attached, laid in a ditch which has some pitch toward the back. Carry this ditch back until it is exits at lawn level. I used a plastic sump well. It is easily cut with hand tools and is low cost. Near the bottom of the well, cut a hole to receive the drain pipe (tubing). This should be a snug fit, but does not have to be water tight. I used standard thin wall drain tubing, but a littlier heavier wall is recommended to guard against collasping. However, I have a 25 yr success with my thin wall. Various fittings are available for the tubing, for example, a Y connector. I plumbed 2 wells together using a Y-connector and then drained both wells out a single pipe. Its ok to let the drain tubing extend a bit into the dry well, say 2 to 3 inches. Once everything is in place a test made to insure that it will drain properly, back fill the ditch and around the dry well. Fill the dry well with fist sized stone for the first 2/3 of depth. We want to create a permeable filter that will support your weight if you step on it, and to keep debris out of the drainage system. Full the top layer with smaller stones until flush with the top of the well. Over time, leaves, sticks, and other stuff may collect on top of the stone fill. Periodically, brush this stuff away. Any small particles that get through the filter will flush on out the tubing. This well will accept a good flow rate and remain clog free for many years. You will need to pay attention to the exit end of the drain tube. Here, it is desireable to spread the stream to slow it down and to counter errosion. If you can establish a good sod layer for the exit, that may be all you need to do. Otherwise, you may need to provide a gravel bed to spread the streasm. If the slope is steep at the exit end of the drain, install some flat rocks to create a tumbling water fall and stream spreader. The hardest part of this project is digging the ditch in which to lay the drain pipe. My soil contained 30% glacial till and that was tough - keep finding stones. To cut down the labor, I used a garden roto-tiller to cut the ditch. I unbolted the outer tines so the the cut width was no wider than the machine. I used the tiller to loosen the soil and I periodically shoveled the loosed soil to one side of the ditch. I carefully piled the dirt in a compact ridge near the edge of the ditch because it was going back into the ditch and it was desired to minimize effort. Mine was an old fashioned tiller with the tines running at slow speed. If one of the tines hit a rock, it merely lifted the machine without breaking any thing. My ditch was 3 ft deep at the dry well. Your installation can be more shallow if you are in a low frost depth zone. You can adjust the well depth by cutting off its top. having the drain pipe buried at least 12 to 18 inches deep tends to hide it presence in very dry weather. In dry weather, grass may brown out sooner above the pipe where it is shallow.

I had lots I didn't get to plant yet too. It actually didn't rain here yesterday it was a nice day but got cold last nite. It is 58 rite now. This is almost July. Potatoes look the best. Cabbage and broccoli are making okay heads I guess, but I feel they are growing so slow but that is due to late frosts and not enough sunshine. I can only get a handful of carrots to come up I'm sure the seed got washed away. Beans grow ing slow. Tomatoes growing slow. Peppers I only have one kind doing anything, that is Hungarian black they have beautiful purple flowers. Other peppers are same size as when I transplanted them. Eggplants too. I planted lots of dwarf tomatoes in strategies and they look okay. Okra are tiny not gonna do nothing. Strawberry are good but now I'm discovering I have some Asian spotted fly and I think it is in my raspberries too. My blueberries look good have unripe berries. Everything is late. Usually by now id have a ton of squash and zukes and cukes. These plants are tiny. Fingers crossed for good warm weather with normal rain fall, destructive winds, hail, and storms to stop. Anyone know a good recipe for grass cuz that's mostly all that's growing. I guess I'll cook it on my compost pile.

The plant list is similar to what you have described Nandina! Chionanthus is definitely on the planting list, next to the bench. Did not know it has both male and female plants. Have already planted several viburnums down below--Sargent's viburnum. And dwarf fothergilla (witch hazel's cousin) in the front, and some red twig dogwoods but I think I will transplant them, I don't like them in this setting. The larger shrubs are mostly our witch hazel collection, so Hamamelis species and varieties. We surveyed a local native high quality natural area to come up with some ideas on plants that would naturally be growing in this situation. One we are going to try along with the viburnums is pagoda dogwood, but keeping deer off of it will be a challenge. We found native currants in our reference plot but staying away from them due to lots of white pines nearby. Hence the maple-leaved viburnum choices. Debating on Illex verticullata because they don't do well with the excessive deer browsing problems around here. Am trying to solve that problem as well! I am planning on perhaps wild blueberries but so far haven't found any low growing ones and I have enough high stuff for the back. They would replace the redtwig dogwoods. The ones I got are cute, with small leaves close to the stem, so very ornamental but they look too contrived in this natural setting. I have a more formal place for them. As for the salt, YES, there are alternatives, but to get the grounds crew to coordinate and think out of the box may take some doing. I have had to re-do the plant list a couple of times. It's sometimes like searching for the needle in the haystack--native, deer resistant, salt tolerant, shade tolerant . . . I mean c'mon!! :) Our soil is limestone base so somewhat forgiving on salt. I have a huge compost stash for ammending and that helps. Also helps to counteract juglone, which thankfully is not really a problem in that area with the one walnut tree. Anyway, I will post the plant list in a bit for anyone interested. Lots of wildflowers, some ferns and grasses, not all for the rock garden, some for the hill down below. Am focusing on shrubs and trees first though. So far I've shown the two schemes/layouts to a lot of folks for feedback, some like the busier one, some like the more formal one. I'll probably do a hybrid. My MS Paint skills are deteriorating so not sure how many more versions I will play with. Eventually I will map the whole thing. Actually doing a map with grid paper next week with my class. Would love to find a site where you could download standard graphics for trees and shrubs and forbs. That would save me having to draw or try and find clip art for them.