Pick up a Western Garden book first since new to CA.
By your name I assume you are in socal, so also pick up Pat Welsh's Southern Calfornia Gardening.
I have a small slope area and my nursery suggested Myoporum and comes in white and pink and it is stays low for walking on it.
You could go native and there are lots that flower, that will definately save on water.
There is the freeway daisy and is multicolored. After a few years it can get woody and need to be torn out and it will grow back. It was on part of my slope and I tore it out was all woody and I am still pulling up seedlings.

Ice plant is a good one and comes in several colors,it's beautiful when it blooms and also serves as a fire retardent.
Kathi

Given the size of the area, you really might want to look into native plants. Gobluedjm is right about the water bill, and you might also want something with a good root system. You might want to look at low growing ceanothus or manzanitas...the Theodore Payne website has native plant library that will sort by use, water needs, etc.

I agree on myoporum, and possibly iceplant.
Ceanothus is beautiful, but if you lose one, there's a big hole.
If you're not from California, you probably need a warning to watch out for gophers. They're not supposed to like ceanothus, but I've lost seversl to those hungry little guys.

Sedums,Aloes,Kalanchoe blossefeldiana,Echevarias,Lampranthus and their spectaculary brilliant blooms.Mix in bunch grass plants like carex.
The fun part is you can start with the faster coverers and spend years picking and choosing the others and all the colors and forms they come in.

It depends a little on where in southern california you are, of course. If you're not too far from the coast I'd suggest ceanothus. It has really beautiful, glossy, deep-green evergreen foliage, unbelievably prolific spring bloom in blues that embarrass lilacs, and even better, it loves slopes as it needs excellent drainage.

The other nice thing about ceanothus is you can mix various types to spread out the bloom period and vary the color. Maybe mix deep blue "Dark Star" with white "Snowball."

Downsides: it's short-lived (maybe 20-25 years at most), won't tolerate extreme cold (most varieties can take, say, 15 degrees) and unless you live fairly far inland you'll have to turn off the sprinklers in the summer as it will not tolerate summer irrigation (although I've heard of people in the central valley who do get away with summer watering).

If you do go this way and turn off the sprinklers, you could mix in a couple of fremontodendrons. These love the same cultural conditions (sunny exposed slopes, no summer water) and have beautiful maple-like leaves and a huge display of yellow flowers in spring. Most people can't grow them because they get huge, but you've got the room.

Manzanitas (as kelpermaid suggests) are truly stunning but they grow incredibly slowly and I find the weeds always get them first, but I can't help trying again and again...

If it is a huge slope, you have room for a nice native hummingbird-friendly garden. Lots of native flowering plants seem most at home on a slope. I suggest Island bush Snapdragon (galvezia speciosa), Bush Penstemon (Keckiella cordifolia), a few sages like Cleveland Sage (Salvia clevelandii), Black Sage (Salvia mellifera), and California fuschias (Zauschneria spp.)

Here's a waterwise website. Tons of info here including fire retardent plants:
http://www.bewaterwise.com/knowledge01.html

For natives:
http://www.theodorepayne.org/ (some really nice people there)
http://nativeson.com/
http://www.cnps.org/
http://plantnative.org/

Natives by zipcode:
http://www.laspilitas.com/comhabit/california_communities.html
http://www.mynativeplants.com/site

More sites
http://www.wildscaping.com/
http://www.huntington.org/BotanicalDiv/HEHBotanicalHome.html
http://www.rsabg.org/

And of course the invasive do not plant list:
http://www.cal-ipc.org/landscaping/dpp/planttypes.php?region=socal
http://www.cal-ipc.org/ip/inventory/index.php

I don't mean to overwhelm you with information but you've got a large area and you only want to do it once of course.

Ladyslppr mentioned a hummingbird garden. That is mostly what I have and all the salvias/sages are on the LA county fire approved list.
I would never go with iceplant but if you do make sure it is the deep rooted kind and not on the invasive list.

I second all of ladyslppr's suggestions. I have a ton of salvia clevelandii on my slope, and aside from its incredible hardiness, evergreen foliage, and prolific purple blooms, its leaves have the most intense, wonderful smell on warm days. (If you're downslope of it, your neighbors may enjoy it more than you do, though.)

For the same kind of invigorating sent, I also have artemisia tridentata--same easy cultural conditions, silver foliage.

Great place for habitat, especially the types that need minimal upkeep. Ditto on the galvesia (Firecracker is my fav, and much larger flowers), cleveland sage, mexican sunflower, cassia and many other natives. If you provide larva plants, you'll get 10 times the butterflies - do a simple google search using the name of your county for ideas.
You can also add Australian / SA drought tolerant plants, such as grevilleas (Ruby Sprite blooms heavy). In areas with easy access, consider cut flower plants, such as protea, leucadendron and leucospermum - with good drainage and NO Phosporus, they're easy to grow.
Buena Creek Gardens is having a sale this weekend, and have lots of the plants referenced in the posts, and they're very knowledgable as well with terrific demo gardens. =^,,^=

Your slope is similar to ours here in S. Diego (5 miles east of the coast), only ours is lots wider (meaning a lot more work!!). My DH planted hundreds of gazanias (sp?? - doesn't look right!) and we've been very pleased. They stay blooming for a very long time, are almost always green and in fact, are already blooming like crazy - mainly yellows, golds and a few pinks thrown in. They seem to not demand a lot of water and have spread very nicely. Even when we experienced a unique cold snap of close to freezing, they survived completely intact.

Whatever you do, do not plant iceplant on your slope. It has a very shallow root system, and as it grows, it becomes top heavy (succulent leaves store moisture) and in a storm slides downhill. Instead of preventing erosion, it CAUSES erosion. There are plenty of examples here in San Jose, along 101 near Salinas, in Fremont's hills, etc.

As others have suggested, try low growing native groundcovers, subshrubs, and perennials for great erosion control value and looks. Perhaps:

Salvia leucophylla Point Sal (purple flowers in spring, loved by hummers, gray foliage)
Salvia mellifera 'Terra Seca' (white flowers, green foliage)
Encelia californica or farinosa (depending on where you live)
Eriogonum fasciculatum (white flowers in summer, loved by butterflies and insects of all kinds, a bird magnet)
Epilobium canum (brilliant red flowers in summer, loved by hummers, cut down to the ground in December, great erosion control value)

There are many many native options, all of which are good for erosion control, habitat value, and even looks. Any time you spend educating yourself about them will be well worth it. Just don't expect mainstream nurseries to give you this information.

One of the ladies in a local rose club had an identical slope, terraced it, covered it with roses, won at all the local rose shows. Do you want to garden with plants you'll enjoy, or just not be bothered, do other things?

Ok, if you're looking for something PERMANANT that will grow FAST and cover the entire slope and not really need anything from you once it's going, you might want to consider a flowering trumpet vine (I believe the proper name is Distictus riversii). I had a huge, steep slope like yours that ran down to a long, dry creek bed, and I just planted two at the top of the slope and it took off! Within two years the whole thing was covered with shiny, dark green leaves and gorgeous purple flowers. I didn't have to do anything, trumpet vines absolutely THRIVE on neglect. HOWEVER, please be warned that they can get VERY aggressive! DO NOT let them climb up those trees on the slope because they will completely overtake them. They'll also probably try to climb along the side fence. Just prune them hard to keep them in check.

What is your zone? What is your soil like? How wet is it?

I had a similar problem and was considering Bearberry. A nice evergreen with berries. I live in a different climate, however.

Most vines would be good for erosion control, but watch out for invasive ones.

Here is a useful link:

http://www.californianativeplants.com/index.php/resources/pdf-downloads/doc_details/171-the-non-lawn-front-yard

I would recommend looking at other people's yards in your neighborhood, as they are likely to have the same type of soil and temperature variations. If you get on top of your roof, you may be able to see several yards at once. I did this in my neighborhood in Westchester and found that most people did nothing with their back yards and let them remain deserts, which is possibly why I do not have problems with pests as much as I did in Venice. Your local nursery will also be able to tell you what will grow in your neighborhood, and you might have an arboretum nearby to visit, although it may not have slopes like yours.

I like nasturtiams on slopes, such as you may see on the Palisades, but they only grow in the winter and spring. You might be able to find an accompanying plant that will grow in the summer and fall.

Good luck, and let us know what you decide.

Lars

I like this thread because we just purchased a home on 1.4 acres of steep, rocky hillside. It is mostly pure weeds and native shrubs, but previous owners have planted fruit trees and others here and there. I have a feeling some have self seeded because they are in weird places..

A previous owner planted a lot of dwarf rosemary, and it's very green, drought tolerant, and looks very nice cascading over rocks and terrace walls.

We intend to plant many more fruit trees and wine grape vines, but these ideas for ground covers are all great!

This post was edited by desertdance on Thu, Mar 7, 13 at 16:03

'Lipstick' ornamental strawberry has beautiful pink flowers, and will grow much easier in the heat than regular strawberry.

Taiwan Raspberry (Rubus pentalobus) grows like a groundcover.

I have been doing a lot of research on plants that don't need a lot of water since we bought a 3 acre property in lake mathews, ca. Here's what I have so far...verbena rigida, creeping raspberry...both spread very fast and require little water. I will be buying these for our slopes. delosperma cooperi is similar to ice plant but very hardy and does not require as much water.... Ice plant requires a lot of water and its heavy. That is what we have currently and we will be replacing it with what I have written here. All our slopes have ice plant and we are trying to save water costs. So I will be adding those ground covers and adding water wise bushes and other plants. Snow in summer also sounds like a good plant to add. They say it spreads fast and it's very nice...

I also want to add fremontodendron, it looks like a nice bush to add...since we have so much room...

Any other ideas?

rq, best to start a new thread. this one is 8 years old.

Here:

http://www.laspilitas.com/garden/howto/slope.html

Evergreen Daylillies. Bloom almost all year too.