Listen to your husband on saying no to ice plant. It can bring down the slope.
To attach pictures, just open an account on photobucket (is free) or similar site and post the link here.
It's very easy.

Flowering has less possibilities than non-flowering. Neat and manicured looking year round is tough, too. Is the slope in full sun, full shade? Is the soil sandy? Rocky? Is there fire danger that needs to be taken into account?

Some iceplants are ok, others will indeed pull down the slope. You need to pick a type that is proportionally light foliaged and deep-rooted, rather than the type that is heavy-foliaged and shallow-rooted.

Of the various ice-plants, only the larger growing Carpobrotus edulis is a hazard with being prone to pulling down slopes in heavy rain. The various dazzling in bloom species such as Lampranthus, Drosanthemum and Delospermum are all well behaved and much used plants for large scale ground cover in coastal southern California. Add Aptenia to the mix of good plants for both fast cover, drought tolerance and good for reducing fire risk. Myoporum parvifolium and its various cultivars is another good thick growing groundcover that is good for weed suppression and reducing fire hazard risk. Rosemary is also much used as a woody groundcover, but is more flammable with age. Cistus species such as Cistus salviifolius is another good shrubby groundcover for full hot sun.

Ceanothus are very good for holding steep slopes together. So are some of the brooms - get one that isn't invasive as it makes iceplant look insignificant in its spread rate.

Gazanias, mexican primrose, lantana, and verbena are all groundcovers I like in sunny situations.

thanks for your replies. here is a pic of our dilemma.

Here is a link that might be useful: {{gwi:527851}}

What a nice area you will have once all cleaned up.
I too have a waterfall and you will love it.
Not sure what the purple flowers are, looks a little like alyssum, but I think it is too tall. I have put in Lantana on part of my slope but it is best to trim it once a year to keep neat and it can get 2 feet tall. I have also put in Ceanothus Yankee Point in an area.
Looks likes rosemary just above your waterfall and rodents do not like it if you have that problem, so I would leave that there if it is rosemary.
The reddish bushes on your upper area look a bit like Red Tip Photina but can't tell for sure. They can get very big.
Don't you want to soften or block that wall some? If you do will it give shade to the slope. Something you might want to think about.

Nice yard! Looks like you have an Avocado, a Camphor cinnamonium, and some Photinia. Keep in mind that as the trees and shrubs grow, the area will get more shady, especially under the Avocado. It looks like the line of Photinia will grow and hide the upper wall. That's a fast-growing, tough shrub. Looks like it was alyssum that was your 'wild flower'??

Here in my neighborhood Aptenia is agressive and will overwhelm anything else planted nearby. It sure will hold the slope in, but will crowd everything else out, including weeds, and cover shrubs if it is allowed to. Gets by with just about no water, too. A couple of the neighbors have it on slopes that are about 4x as tall as yours. They have to negotiate that slope to keep the aptenia from covering the shrubs. It needs to be kept trimmed back.

It does look like you may have Lobularia maritima/Sweet Allysum as your wildflower on the slope, this can actually be a decent long term groundcover if you trim off the old flowers to refresh it from time to time. It also looks like your slope has quite abit of shrubs planted out which will fill in the areas within the next several years, so you don't actually have large areas that will remain sunny and exposed. Bark mulches such as Shredded Redwood bark that is stringy, and often called "Gorilla Hair Mulch" would work on that slope without washing off if you just want to mulch it. It does look as if the existing shrubs will completely fill in over time on the slope, so any groundcover will be shaded out over time. One of the Lampranthus or Delospermum types of iceplant would work well in this situation, dying off as they get shaded out, and can be bought cheaply from mud flats or cell packs.

Have you thought about using ground roses? They can spread quite a lot and, depending on which one you choose, put down many baby plants. I have Sun Runner, Baby Blanket, Magic blanket, and Garden Party -- which is the BIG spreader and baby maker. There are a lot more kinds to choose from now than when I put mine in 9 years ago.

How about the low-growing sedums (and/or other succulents) for ground covers? They need almost no water, thrive in sun to light shade, seldom get more than a few inches tall, have pretty flowers but even prettier foliage in lots of different colors. You could mix and match, create a beautiful succulent patchwork on that slope.

On April 28 there will be a FREE mini-workshop on "Landscapes Minus Lawn" in Kearny Mesa that could be very helpful in identifying other groundcovers suitable for your needs.

Here is a link that might be useful: Landscapes Minus Lawn Mini-Workshop

I know they're not flowering, but how about ornamental grasses? The native deer grass is very nice and requires little water. Also, you may look at low growing grevilleas or coprosma 'marble queen'.

Ditto on the ornamental grasses! Not only Muhlenbergia rigens but also Nassella tenuissima. I just saw a large planting of it blowing in the wind, and oh, MY! Wish I had a blank hillside right now. :)

Brenda