Does anyone have recommendations on how to get good plants growing on a rocky slope in the Austin TX area?

I have planted a few seedlings which ended up dying after some concerted efforts to keep them going with water. I'm assuming that the low seedling count combined with the fact the plant didn't originally grow in the soil may be contributing to the failed efforts. (Not to mention the uncharacteristic cold snaps we had this year.)

Was wondering if my chances of success would be increased if I did some broadcast seeding. I'd assume that some percentage of the seeds would make it and hopefully propagate from there.

Issues:

1: The ground/slope is dry and of course well drained.

2: Some areas are difficult to water due to access. May not be able to water regularly.

3: One side of the hill is full sun while the other is shaded by trees.

4: Deer in the area.

Would getting some seeds on the side of the slope be worthwhile or am I just wasting my time?

I'd also appreciate any suggestions as to what to plant. Looking for colorful erosion control plants, originally tried rosemary have had luck with santolina. Was thinking

Any input is greatly appreciated.

Regards,

Mike