Hi. A few questions: How much sun do these beds get? How deep are the beds? Do you have any color preferences?

For the bed that can't (easily) be watered, you might consult High Country Gardens; they sell many perennials that don't need much water (you don't have to buy from them, but they have good info). I can particularly recommend their white coreopsis, which I planted this spring; it seemed actually to enjoy and thrive in our blistering summer with long rainless periods -- but don't plant it unless you don't mind tons of seedlings. It may also be lower than you want. It's the only coreopsis I've grown in decades, and I don't know if other coreopsis cultivars have those traits.
http://www.highcountrygardens.com/

Also successful without as much water as it would have liked were the gauras I planted; the one that was planted earlier in the year (and isn't reachable by hose) did well on less water, while the one I planted later and watered more is now too wide for its location!

Daylilies store water in their roots and can survive without much care, provided they get some good waterings when they're first planted. Buy varieties that rebloom and you'll get more than one blooming period per summer (though mine that weren't watered this summer when there wasn't rain during the critical period didn't rebloom). Buy your daylilies from a specialty vendor for better choice.

Other perennials which were happy this hot, dry summer were the rosemaries and lavenders I planted, and last year's pinks and chrysanthemums.

Some years back, I filled an empty bed with ox-eye daisies from the pasture. They don't mind not being watered -- but do need to be deadheaded occasionally. Another freebie that I would consider is the local wild white aster (don't know which variety it is, but other than having small flowers, it's a better-looking plant than most wild ones).

[You might want to change your setting for "Show personal email" to "None" so you aren't flooded with tons of spam.]

Probably the most important thing is to make sure that whatever you plant is not on a list of things toxic to horses! And it's a good idea in any case to plant them far enough from the fences that at mature size they are still out of reach for the horses to browse on. That will also make maintenance of the fences easier.

Here is a link that might be useful: Plants toxic to horses

If you're trying to figure out how to "fill up" a bed then maybe it is bigger than you need.

Or will be able to keep up with.

Agreed you need to keep the horses saftey and well being in mind. Whit this in mind the bed is long and you could according to exposure and light requirements do repeats. Shrubs or trees underplanted with perinnials that are native to your area. This could include some grasses to keep maintenance down. This type of planting needs to be thougt out and planned but will give you good results. I try to keep planting areas like this to a minumum. Three to five types of plant material with the option of up to seven but that is pushing it. You still need to maintain it within reason. So the trees being the first and then the shrubs with perinnials being the last. Let the perinnials shine while the trees grow. Shrubs will most likley do the best for fill. Such as evergreens for all year interest. Wow there is alot you could do with this type of space. Good luck!

The fence line behind the house has abelia along it. Also has privet and wild cherry. I chopped the abelia down to about 24 inches and now want to plant. Need a chain saw for the others. It seems the suggestion is to plant trees first and then grouping of shrubs along the fence at intervals and keep the plant material the same.

I would love suggestions as to what kind of trees and the spacing, as well a the shrubs. Perhaps fruit trees? And roses for the shrubs. It is a long space! Thanks for the help.