Need ideas for ground cover plant on a slope for event venue

Our wedding event venue is in a rural area and the drive way is a good block and a half long. Both sides slope terribly down making it nearly impossible to mow, one side slopes straight into a barbed-wire fence. It is a pain to mow the long and sloped area every couple of weeks, not to mention dangerous. I wanted to plant a English Ivy along both sides along the whole drive which would look great to me, but I read that horses can get sick and even die from eating ivy which is a pain since the shortest distance of the slope drops down to my neighbors horse pasture right next to the most used area for the animals. Is this true that Ivy can kill them and if so what would be another litle-no maintenance ground cover that would be safe for the animals, not take over the countryside and still kill all the grass/weeds growing along these slopes?

English ivy is toxic to horses should they choose to graze in it, but they rarely do due to its very bitter taste (meaning also if they're starved for food elsewhere too, otherwise they steer clear of it). Also, any intake of it would have to be in very large quantities to spark a physical reaction (foaming mouth, enlarged pupils/eyes) and is rarely, if ever, fatal in any event. Ivy would be PERFECT for your slope the in event venue although it does creep, including climbing up fences and trees, so is not maintenance free and needs to be sheered back a few times each summer where not wanted. It also has the advantage of being a very dense cover such that unsightly tall weeds are a lot less likely to peek out and grow through, thus not requiring more than the initial mulch-job when first planted and establishing itself.

Another choice - which is NOT toxic to horses or any other pets for that matter - would be crepe myrtle (which also has a lovely little blue flower in spring) but it is nowhere near as dense a cover, takes longer to 'fill in' and thus you WILL see unsightly weeds peek through unless you double up on plants and jam them in to get as thick and protective cover as possible. Another idea, but MUCH more expensive initially, is the vast array (and colors from deep green to medium green to blue-green)is creeping juniper. Another good choice is Euonymous Fortunei, which is also great for erosion control, is evergreen and dense, with inconspicuous flowers. You haven't said whether you are dealing with full sun, part shade of full shade, so choices should be made in consideration of same (for instance lily-of-the-valley works too, has great fragrant flowers, but burns out in full sun, needs part shade.