Hi,I'm assuming You have St Augustine grass?If so,it will eventually creep back into that part of the yard.If it were me,I'd extend my irrigation to hit that part of the yard-that may mean running some PVC & adding a few sprinkler heads,but that would be fixing the problem ,rather than just adding a temporary solution.Hopefully we are entering the wet season,which will help the grass recover.In the mean time,depending on the type of curbing at the street,You could add a landscape edging to save loosing any more topsoil over the curb & I think any mulch You have,would be better than nothing to help slow the run off.If you do decide to address the irrigation,then use the "deep soak" method to water the lawn.this will cause the grass to send down deep roots(even in sandy soil),which helps it survive a drought better & prevent erosion.Good luck & I hope this helps

Thanks, I was thinking too about a landscape edging to help slow the soil from running off. I'm gonna price them tomorrow at Lowes, I have a coupon ;). Thank you for the input!

If you want to go low cost,You could just use some recycled cardboard for edging.This is just a temporary edging until the grass takes root.I don't know if You live in a community with an HOA,but even if You do, You could explain that it is just a temporary barrier until the grass takes root.As a bounus,the cardboard will decompose & add organic matter to the area.I meant to add in my first post,that the reason I would just try to re-establish the lawn at the roadside,is I would bet You have a "Public right of way" or "utility easement",also known as a ROW on Your property at the street.What this means,is if any utility company or the city/county needs to lay any new lines,or excavate any existing for servicing-then they have the right to do that.They are not required to re-plant anything except sod that is in the ROW.

The problem with more sod is that I want to get rid of the lawn eventually and replace it with a more drought friendly native and edible landscape. Plus any grass I plant there, I'm still going to have to water by hand. I can't redo the irrigation system at the moment. I wanted to get some of the scalloped edge pavers and place them along the edge of the road. We do have ROW, in fact the utility co just dug everyones yard this year, but they take the most direct approach and didn't dig up too much. I'm aware that they might dig again in the future. I don't to spend a lot of money either. No HOA here. In addition to the scalloped edge pavers, I planted some cordgrass and muhly grass. I'm going to the nursery today and see about a couple of other tall grasses and some flowers, then mulch it. I'm hoping that does the trick with the pavers in place. I also dug a small trench on the crest of the hill right before the grasses and lined it with lava rock, to act as a drain of sort, the theory is the water should be absorbed directly at the root level of the grasses.

We had this exact problem and planted dune sunflower on our slope. It's doing very well but an HOA may not like the wildflower look, unlike our neighbors. 3 of them have asked where we got it and I've given them starter plants.

It does get frost bitten at 32 degrees but we never water it after the intial establishment period of about 4-6 weeks.

Cost is $5/4" plant which we planted 2-3' apart. They can occasionally be found at big box stores but a native plant nursery is your best bet.

On the other side we planted mimosa but that took 2 years to get going. Looks good now though. No watering either.

Here is a link that might be useful: mimosa groundcover-scroll midway down

I was thinking of beach/dune sunflowers as well - they make a very cheerful groundcover in full sun. The 'Sunshine' mimosa also has very pretty flowers & forms a low-growing mat.

There are so many grasses to choose from; purple fountain grass is colorful. And Natal plum comes in a spreading form & does well in sand.
I was having a similar problem w/ a curbside area - not as much slope, but washing into the gutter w/ every rain & nothing but silty sand, Bermuda grass & weeds, so last month, I weeded it completely (hand dug the Bermuda!), laid down landscaping paper (cardboard works too) & covered it w/ a couple of inches of our city log mulch, then watered the area very well. I left 2 sunflower plants that had self-seeded in place & now they are spreading nicely. I have a couple of the above-mentioned natal plums & some cord grass I plan on putting in there as well.

W/ anything you choose, you'll likely need to keep it watered well until it's established.

This is a heckuva time of year to be out doing yardwork, tho - best to do it early a.m. or after 3 p.m. to avoid heat stroke...

Here is a link that might be useful: Floridata plant lists

Yeah thanks guys. I do any work outside early or late after sun goes down. I came home with some Purple Fountain grass, said grows 1-3 ft, to go with the cordgrass and muhly I already planted. I also came home with more Coreopsis, and one Gaillardia (50% off! last one). I have planted already 3 coreopsis (dwarf) and some portulaca that keeps popping up in the yard. I know I will have to weed eventually but I'm afraid to pull anything that is growing at the moment! I think I will pull up weeds and remaining lawngrass after my other plants are established. I will water them till they are established and occasionally if they need it but my regular St. Augustine needs to be watered at least 2x a week or it starts to die back.

I also took some seeds from a very pretty beach sunflower that I found at the park ( the seeds only, just a little bit :), I also have some other Gaillardia (indian blanket) in the back that I started from seed and when they get bigger they'll go out front too. I also found a patch of beach sunflower out back that I'll attempt to propagate further. Seeds just take so long to get going I had to buy some already grown plants.

Gosh it's so much work though :) Let's hope it works! I'll update after I get it all in.