I have deer creating a hole right behind my house----they are attracted to water that pumps out of the basket pump in the basement because the water softener drain into the basket and then gets pumped right behind the house. They seem to really like it!
I'm not understanding why clover dries up in the summer heat if the roots can go that deep? I thought that chicory did better in the dry spells because of it's deep roots(always thought chicory went deeper than clover). I'm in minnesota though so i can only imagine what REAL summer heat is...
Seeding now probably won't work nearly as good as fall planting or frost seeding in spring. Plants need to get some roots established before being frozen for several months.
That sucks but I think I would wait---how far did the seed wash? 3 feet? 300 yards? If there is any slope at all it probably washed most or all away but if it's flat land you might be ok.
Looks like you have room for another 3% at a glimpse. Mix doesn't look too bad---I prefer foodplots with as many different things as possible as long as they are compatible. With diversity you usually can have something growing for the deer at all times.
If they are large enough that they are getting more brittle they will break. If they are still flexible they should be fine. Even if you do break some off it probably won't be a big deal unless you need to drive all over it to spray? What are you driving to spray? Tractor--4 wheeler--bicycle?