I am very fond of Italian cypress (Cupressus sempervirens ‘Stricta’ , C. s.’Fastiigiata’). I know some people don’t like them, but I love the look of them and their atmospheric quality pleases me. They remind me of Italy, and fit in with the Mediterranean garden style. I have three in my own garden and have pruned off the lower branches so they look like the trees in Renaissance paintings. (But if this look is desired it should never be done until the trees are at least 10 or 15 feet tall.)

Italian cypress need good drainage. In general, since these trees are drought-resistant, deep infrequent watering is preferable to frequent and shallow watering. However, if you want them to grow fast you will need to fertilize and water for rapid growth. In heavy clay soil Italian cypress can die from root rot, so in this case they are not a good choice. Canker diseases have also been a problem in recent years and there is said to be no cure, but good health can help trees throw off problems.  It used to be said that the best time to fertilize is in March, but those rules were for synthetic fertilizers.  When fertilizing with organic fertilizers, earlier is better since it takes time for them to work. For example, applications of manure in fall before the rains are good, or apply adequate quantities of commercial organic fertilizer in late January and water in. Grow Power is not fully organic but plants thrive on it. If  you choose that, I would apply it in mid-February.

Also, mulch the trees.  Organic fertilizers and beneficial insects can help Italian cypress withstand attacks of spider mites. People who grow roses organically for example have no spider mites on their roses. My Italian cypress do not suffer from spider mites but I live near the coast so hot dry weather is not a problem. Cypress trees in the Hollywood hills are looking okay also. Strangely enough the smoke from last year’s fires probably smoked the trees in the hills and did them some good since they all got a big dose of carbon, and doubtless the smoke killed some of the pests also. Additionally flowering trees and plants doubtless benefitted from the ethylene gas in the smoke. (Nice to know that a fire that does so much harm also brings about some good.) When my town was filled with smoke for a whole week a couple of years ago, the growth and health of our trees and the number of flowers on flowering shrubs and trees were extraordinary for a whole year thereafter.

Though the problems with pests and diseases mentioned above have afflicted Italian cypress in recent years, I believe that good cultural practices (also explained above) can keep these problems under control so if these are the trees you love, why not have them? Other columnar type trees for a rapidly growing screen include several varieties of podocarpus, and as you suggested, junipers. You might not like x Cupressocyparis leylandii, but I’ve seen it growing in a narrow side yard and pruned to fit. (Their gardener did this job at regular intervals for 50 years.) It’s hard to choose between ‘Spartan’ and ‘Skyrocket’ junipers. I like the color of ‘Spartan’ Juniper better than ‘Skyrocket’, but ‘Skyrocket’ is a little faster growing, I think and it’s very narrow with the reputation of fitting into a narrow side yard with little problem. Monrovia Nursery grows both these varieties. ‘Spartan’ might be better adapted to growing in California since it’s said to grow even in Zone 10. Is there any chance you can view these varieties growing in a landscape near you? That is often a good way to make a choice.

Related posts:

1. Cypress Canker Disease on Italian Cypress
2. Blue Sapphire Cypress (Cupressus arizonica ‘Carolina Sapphire’)
3. Pines, Cypress, and Cedars

All nurseries will provide you with information when you purchase plants as to correct spacing of the plants you buy. Most plant labels have size and spacing listed on the label. Always ask the correct spacing of plants at purchase time. If you failed to do this, you can find information on spacing in paperback books on landscaping and ground covers, and on the internet. As a general rule, it is not an appropriate use of my time to be providing it since there are so many thousands of different plants that we grow here, and each have different spacing. Nonetheless, since you wrote to me, I will provide it this time, but I would like to help you find this sort of information for yourself. For example, if you had simply Googled “Correct spacing for Bougainvillea ‘La Jolla’ “you would instantly have gotten the information: 6 to 8 feet apart. Now it’s time to use your head. Ask yourself: “Am I going to plant in drifts for an all-over look? Or am I going to dot these plants on the hill with the ground cover between them?” These kinds of thoughts in your head will help you to come up with sensible answers: For example, you might decide to put the plants further apart—as much as 15 feet apart if other plants such as plumbago and lantana are going between them.

Here is an example for how to find out correct spacing of all garden plants. Look at the label of your plant. It may provide spacing. Most plant labels do. Or it may provide mature size. Or to find out the mature size, if the label fails to say, look up the eventual size of the plant up in Sunset Western Garden Book, a plant encyclopedia every gardener needs. (My book does a different job. My book tells you when to do what and how to do it.) Sunset is a complete encyclopedia, an alphabetical list of almost every garden plant we grow in the West. It provides correct spacing for many plants or when not providing spacing it provides mature size. My book does not try to replicate this, that would be senseless. My book belongs side-by-side with the Sunset Western Garden Book and the two books work together, Sunset naming and describing the plants, and mine telling you what to do when.)

(Also in Sunset, there are some informative pages in the back on basic information. Please read page 726 How to Plant Shrubs and page 691 How to Plant Groundcovers. Also look at the index on page 764 for other planting guidance that might help you.)

Now here’s how to use Sunset to find out correct spacing when it is not provided: In the latest edition of Sunset Western Garden Book on page 552 (the most recent edition), it describes the mature size of Plumbago auriculata as making a mound 6 feet tall and 8—10 feet wide. Plant the specimens so they are exactly the same size apart as the eventual mature size of the plant, that is 8 to 10 feet apart. This is fine also for ‘Royal Cape’ or ‘Imperial Blue’, whichever one you purchased. (You mentioned ‘Royal Robe’, but I think you said that by mistake. ‘Royal Robe’ is the name of the best Solanum rantonettii, another lovely plant but it is 6 to 8 feet tall and wide and looks best with more water, so not as good on this bank.)

Find the spacing for all your other plants in the same way as I have described above. The correct spacing for every ground cover should be provided on the plant label or provided by the nursery if you phone them, but for many 6 to 8 inches apart is about right. Some shrubby plants should be place 12 inches apart. It all depends on the mature size of whatever you are planting and the way a plant grows whether creeping or not. Take the mature width of the plant and you then have the correct spacing, or for a quick cover you can put them a little closer.

Yes, you can purchase lantana in flats and if you do, then plant them closer together. But the variety of lantana that is most frequently available in flats is a species called Lantana montevidensis, which is a purple, trailing lantana, not the same color as ‘Radiation’, which is a whole color scheme in one plant and is a more shrubby type. When planting lantana from small plants from a flat, put them closer together, —about one foot apart— than you would if planting from one-gallon or five- gallon size.

Regarding the ivy (probably Algerian ivy) it would be best to cut it off and keep it cut off and pulled out on your side of the fence. This is what I do in one part of my property where a old bank of ivy is separated by a flight of steps made of concrete sacks from the rest of the garden. We just keep policing and cutting it off and pulling it out and this way have successfully controlled it for many years. You can plant right over the ivy if you want, but unfortunately it will eventually climb up and cover over some of your plants, spoiling their appearance. It will, however, help hold the bank.

Yes, birds will be attracted to these plants, but you didn’t mention until now that attracting birds was a priority. Had you done so I would have suggested an entirely different group of plants. However, hummingbirds will visit the plumbago and lantana flowers. Butterflies will visit both of them, but for lists of plants especially attractive to birds (and other pages of plants attractive to butterflies, and many other specialized lists), please see the book I wrote called “The American Horticultural Society Southwest Smart Garden™ Regional Guide.” I wrote this book of lists to help gardeners such as you choose plants according to where you are going to plant them and how you will use them. Plants that are especially attractive to birds are listed, described, discussed, and pictured on pages 132, 133, 134, 135, 208, 209, 210, 211, 242, 243, 298, and 299. (Also see the list of all the lists contained in the book on page 82.) In my copy I have written the page numbers on every page, since many page numbers were omitted by the publisher, D.K. This is a beautifully designed book, but the publisher D.K. had the crazy idea that page numbers on every page would screw up their pretty design, so they would not listen to me when I told them there should be a page number on every page. Reference books need page numbers, and this is a reference book, not just a coffee table book.

Related posts:

1. How to Space Plants when Planting a Bank
2. Formal Garden and Informal Plants
3. Where to Find Photos of Pat’s Garden

Question from Cat:

Answer from Pat:
Thank you so much for this enquiry. About seven years ago my insurance company informed me that they would need to greatly increase my homeowners insurance if I continued to open my garden to tours and visits from the public. That put an end to visits to my garden from members of the public. Now my garden is back to being what it was always meant to be in the first place: A happy outdoor space for my own enjoyment and for the enjoyment of family and friends. The time felt exactly right. There are many great gardens out there, far better ones than mine now is. It is time for younger folks to take over.

Since making that decision, I’ve been simplifying my garden and making it easier care and more drought-resistant. I got rid of all my tubs and containers or most of them, pulled out all overly-thirsty plants, covered the spaces with mulch, replaced some with natives, added new potted arrangements of succulents, and installed a huge succulent bank next to the drive. It hardly ever gets watered. I’m now saving about one hundred dollars on every water bill. I’m also trying to resist temptations that arise sometimes to add more plants. The main additions today are fun things for my great-grandchildren, like potted “fairy gardens” and a projected “dinosaur garden”. We already have a “pirate garden” and may make a hobbit house or two. Wandering paths and flights of steps I made of sacks of concrete, hardened under the hose, already create fun places for my beloved great-grandson Archer to run around on. But I have to tell you I simply adore all four of them: Archer, Anushka, Fable, and Jade.

Here are some photos of my garden taken last Easter by my granddaughter Rebecca Woolf.
http://www.girlsgonechild.net/2010/04/garden.html

She has posted some other ones also: Click on this link to a photo of the very simple “fairy garden” I made with the help of my friend Denise.
http://www.girlsgonechild.net/2009/11/treasured.html

Regarding Great Dixter, Christopher Lloyd and I were friends. He visited my garden years ago. I visited him with my granddaughter Rachel Woolf when she was 13 years old and I took her on a trip to Spain, Scotland, and England. Christo gave me the room in which he was born. Rachel had been in another room but after going to bed, crept in to join me, even though Christo had said very decisively “My house is NOT haunted!” (We didn’t say it was, but you know he was a character.) So while we were there we both slept in the bed in which Christo had been born. That whole long weekend was a great experience and we drank a lot of very good champagne. This photo was taken by a lovely visitor to the garden during one of our afternoon walks around the garden. (Please say hi to Fergus.)

Related posts:

1. Thomas Welsh
2. Multi-media Garden Mural: How to Create
3. Romancing the Garden: A philosophy of gardening Pt 4

From Kathy:

I thought maybe two bushes on the bottom in the slide area one aon  the top part of the easement on the bottom slope  and then put another one further down toward the street.  How many do you think I need for the upper part?

Answer from Pat:
To space plants properly, first measure the space, then look up the plants in Sunset Western Garden Book, or in paperback books on ground covers, or ask your nursery. Every plant has appropriate guidelines for spacing. (ie, how many feet or inches apart the plant needs to go.) Some landscapers put plants much too close together for quick effect.This is a bad idea since after a year or two the homeowner is always needing to cut back. You can figure out how far plants need to be put apart from each other, simply by knowing the eventual size of the plant, and doing a plot plan so each plant fills that amount of space and the edges touch. For small groundcovers. make a triangle of cardboard, each side being the distance apart. Use it for placing plants at appropriate distance from each other in a triangular, diagonal pattern.

Related posts:

1. Planting a Bank
2. Planting on a Bank & Best Substitutes for Lawns
3. Correcting Erosion on a Steep Bank in Encino

Question from Howard:

Answer from Pat:
Before I can answer your question, I need to know where you live. Plants are adapted to certain regions and not to others. I cannot give you any suggestions for what to plant without knowing where you live. For example, what if you live in the Middle West, or Arizona, or New England? Your question gives me no clue. My recommendations for planting a bank in each of these regions would be totally different. Also, if you live in Southern California, or anywhere in the west, please tell me what Sunset Climate Zone you live in. (Please do not give me the USDA Climate Zone since they are not specific enough.) If you give me your Sunset Climate Zone, I will know what plants to recommend. Also, please refer to my suggestions to other readers who have written with questions about planting a bank. Perhaps I have already described a bank planting that will perfectly fill your needs. You will find many suggestions included in the answers given on the following link: Plant to Prevent Erosion on a Steep Hillside.

Related posts:

1. Planting a Bank
2. Planting & Growing Zone
3. How to Space Plants when Planting a Bank

Question from Kathy:

I have a new problem and do not know what to do. I live on top of a steep hillside and have been here for 34 yrs. I have never had a mudslide. However, the hillside is in three levels and the bottom one had a some mudslide last winter. It was covered with the old heavy ice plant and the woman who lives across the street from my hill started pulling it out and planted red apple and some nasturtiums as she didn’t like the weeds in between the ice plant. Now I need to know how to fix this problem.

What is the best and toughest ground cover ?

I live in Rancho Palos Verdes. The slide is about 3 feet deep by about 4′ wide at the top and a narrow 9′ down to the street . It has thick red apple on one side and scattered old ice plant on the other side. Thank you so much

Answer from Pat:
Thanks for kind comment. Below are a lot of ways to fix a steep bank. I think I was considering a larger space than you actually have, but I have given you so much to chose from you can make it fit your needs. Also this advice may help others who read this site.

As you undoubtedly know landslides on the Palos Verdes Peninsula can be a serious matter since they might signal a problem with an entire strata of wet adobe soil slipping down over a harder layer of soil below. This kind of slide can happen when the “tow” of a hillside has been unwisely bulldozed or cut into. It might be wise for you to contact your UC Extension Home Horticultural Advisor, Department of Agriculture, or your local city officials before trying to do anything to correct the slide so you can first make sure there is no serious slippage problem in this case. In many cases in the past mudslides have endangered houses or even lives, though yours sounds smaller in scope than were those.

Once you have determined that this is not a widespread or potentially dangerous situation, then you can undertake some steps to try to correct the problem. First, ice plant is seldom a good solution for a very steep bank, since it can actually pull a bank down by its own weight. Nonetheless if it is growing there already and holding a bank it’s unwise to pull it out as your neighbor did since this can make the whole bank slide as happened in this case. A wiser way to make a change is to cut the ice plant short and leave the roots in place, then plant right through it. The roots will continue to hold the bank while the new plants take over. It’s too bad your neighbor didn’t know of this old-timers trick, a common practice in California gardens fifty or sixty years ago when people with new homes covered banks with ice plant quickly to hold them through winter rain then soon upgraded to something better.

Also, red apple ice plant is not a very good solution for steep banks since it needs a lot of water and calcium nitrate fertilizer to stay green. It’s far better to plant something more environmentally responsible. When trying to plant a bank for the purpose of stabilizing slipping soil, the very best way is to plant a mix of deeper- rooted larger plants along with shorter-rooted ground covers to cover the ground between them to hold the ground as the larger plants are getting going. Examples of shorter rooted ground covers are gazania or arctotis. Then you could dot such plants as shrubby bougainvilleas all over the bank, along with something like ceonothus ‘Concha’. I recommend bougainvilleas as one of the better plants for such an area. They will grow on a drip system and grab deeply into the soil. Once fully established they become very drought-resistant and you get a lot of bang for the buck. Another fairly deep-rooted bank cover plant is Acacia redolens ‘Desert Carpet’ or ‘Low Boy’. This too is very drought-resistant once established. Lantana montevidensis is hugely colorful with lavender flowers almost year round and also very drought-resistant, easy to grow and good on banks. Finally consider blue plumbago. For a gang busters combination on a bank and drought-resistant year-round color, plan yellow trailing gazanias to cover the ground, then use an equal number of the the following plants to send down deep roots and hold the soil: Bougainvillea ‘La Jolla’, Plumbago ‘Royal Robe’, and Lantana ‘Radiation’.

Another way to go and perhaps more exciting, but best planted in November: You could do the whole thing with native plants. You might try toyon or Calfornia holly (Heteromeles arbutifolia ) at the bottom of the slope. (Get the one from Catalina that has bigger berries.) For a native shrub requiring no water whatsoever in summer, plant flannel bush (Fremontedendron ‘California Glory’.) Or, for a compact one, try F. ‘Dara’s Gold’. Plant this next to ceonothus for a great color combination blooming at the same time in spring. I think natives are probably the way to go with this slope but you could get a ground cover going first to hold everything until fall. Matilija poppy (Romneya coulteri) is a great way to grab a bank but not a good time to plant now. I planted three of these last November and they are all growing and blooming. All natives are best planted in November but it would be all right to cover the bank now with some native ground covers though perhaps not California perfume (Ribes viburnifolium)—great on banks but might not survive planting now. But bear berry (Arctostaphylos urva-ursi) or coyote bush (Bacharis pilularis) I think might mostly survive along the coast even if planted now since we’re having cooler than usual weather, and then plant the bigger things in fall.

Related posts:

1. Erosion Control for Steep Hillside: Last Minute Installation to Hold the Soil
2. Correcting Erosion on a Steep Bank in Encino
3. Native Plants for Erosion Control on Steep Banks

Question from John:

When and exactly how do I trim and shape this tree with the hope of having a well shaped Caphor tree that will have an umbrella effect in our yard?

Answer from Pat:
I think I should start by telling you that Fact Sheet ST-157, November 19, 1993 of the US Forest Service on Cinnamomum camphora (camphor tree) states “Avoid upright multi-trunked trees” and also “It may be difficult to maintain a lawn under this tree.” Unfortunately I see you have a multi-trunked tree and it’s growing in a lawn. Now for your questions:

“Scaffold branches” are the major structural, trunk-like branches that originate off the trunk of a tree. Now let’s discuss the problem that you have a multi-trunked tree when what you require is a single trunk tree. You should remedy this situation immediately. Step one is to choose the strongest trunk and cut off the other competing trunks immediately down to the ground. Afterwards, if any more sprouts or suckers spring from the ground, always cut them off right away. You just want to let one upright trunk grow, not several.

After you have cut out all trunks except one I suggest you once again contact the landscaper and hold him to the terms of his contract to come and prune your plants or perhaps have a family member or friend phone for you and insist this be done. Your situation sounds like a bit of a sad tale to me because I get the feeling your landscaper is giving you the runaround and taking advantage of you because of your age and this is not right. Also he evidently sold you a multi-trunked tree which is a serious no-no.

If your landscaper never shows up, hire a certified Arborist to train the tree, or begin the training of the tree yourself, following the step-by-step instructions I already sent you. Taking your probable physical ability into consideration and if money were no object, it would have been better for you to begin with a boxed camphor tree from a tree farm that was already growing with one trunk and appropriately pruned for use as a street or landscape shade tree with proper scaffold branches in place. If you can afford it, perhaps you should have the existing tree removed and replaced with a boxed single-trunk camphor tree now.

For homeowners who have no problem with training a young tree, it actually is far better to begin with a small 15-gallon, single-trunk tree. Once in the ground and properly cared for, a smaller tree will actually out-pace the growth rate of a larger boxed tree and you will end up getting a proper shade tree sooner. But for elderly folks who have a problem shaping and training their tree and certainly don’t want to be climbing ladders, it would be better to begin with a boxed tree that is already trained and shaped.

Now in regard to your question about why you should leave the lower, bushy side branches on the bottom of the trunk, this is because they will help your tree to form a strong trunk. I explained this before but maybe I should say it another way which is this: It is unwise and improper to cut low branches completely off a young sapling shade tree. You can cut them short, that’s okay, but don’t cut them off since cutting them off will weaken the tree and make it take much longer for you to get a proper shade tree. It’s fine to prune the bottom ones so they are only a foot or two long and leaves don’t trail on the ground, but be sure to leave them attached to the trunk.

Perhaps you are having difficulty following the instructions I gave you. If so, I suggest you purchase a good paper-back pruning book, such as “Sunset Pruning Handbook” and follow the instructions in that book for training young trees. Get one that includes diagrams and then you will immediately understand what I’ve told you to do. (My Sunset pruning book includes diagrams showing the young shortened branches left on the bottom of the tree, like I have told you to do.) But the most important thing to do first is to be sure to cut off the extra trunks at ground level right away since they are sapping the energy of the main trunk of your tree and it will now may take another year at least for your tree to develop a proper head and trunk with appropriate scaffold branches and a rounded crown.

Regarding your fern pine trees (Podocarpus gracilior, Afrocarpus falcatus), prune these in spring or summer, so now is fine. Cut back the side branches to make them stronger, as your landscaper told you to do. This will encourage them to be bushy, but whatever you do don’t remove these side branches. Growers grow P. gracilior in two ways. One way is to grow them on a single trunk grown from a seed. This way of growing it makes for a strong trunked street or lawn tree. The other way is to start them from cuttings. Podocarpus grown from cuttings are sort of floppy and willowy. This type is used as a bushy hedge and this looks like what you have got. I am supposing that these are planted to act as a sort of screen hedge, not to grow to full size as trees. The branches will be floppy and flowing so you want to cut them short and encourage the tree to become a hedge. Another way to go is to wind the branches of one of them around the branches of the tree standing next to it and they will make a natural graft to create a sort of espalier and hide the wall. But be sure to pinch the tips. It’s up to you how you want to train them, either as columns or as a green, leafy hedge. You may need to stake them to keep them erect. Once you have trained these trees to the size and fullness you want you can then shear them with hedge shears, if desired.

Related posts:

1. When to Prune a CAMPHOR TREE (Cinnamomum camphora)
2. Pruning New Zealand Christmas tree close to a swimming pool
3. Ficus Tree pruning and fire danger

Question from Candace and Cyrus:

Answer from Pat:
One of the most pressing current needs of gardeners is a drought- and-wear-resistant ground cover to take the place of a lawn, especially for people who have dogs or children who love to run and play and can wear out many kinds of ground covers. My suggestions are these: First a bermudagrass lawn such as ‘Santa Ana’ or ‘Tifgreen’ is grass but it is very drought-resistant and will stay green along the coast even in winter and will take no more water than gazanias. In a drought it will pull in its horns and go brown but it will not die. It is far better to water it longer once a week than more shallowly and for less long three times a week as some cities now mistakenly legislate.

Secondly I suggest planting creeping white yarrow or woolly yarrow (Achillea tomentosa) as a lawn. Plant seeds in fall and keep the ground damp until they are germinated. It will take a little time to become established but it will eventually make a ferny green mat that is very pleasant to walk on and very durable. The flowers are a bonus and can be taken off after blooms fade with a weed-wacker.

Thirdly I suggest Lippia (Phyla nodiflora). It is a drought-resistant, low groundcover that takes foot traffic, but it does bear pink flowers in June that bring bees. You can mow them off in June with a lawn mower in order that your dog’s paws won’t get bitten. (Bees in the garden don’t bite except when you accidentally step on one or grasp one by mistake. Bees do protect and guard their hives, however, but having a lawn that attracts bees won’t cause bees to make a hive in your garden.)

Related posts:

1. Creeping Yarrow (Achillea millefolium) for Lawn
2. Drought-Resistant Gardening
3. Variegated Carmel creeper (Ceanothus griseus horizontalis ‘Diamond Heights’ as lawn substitute

Also, do you have some advice on peaches, nectarines, plums and cherries? I have trees that are two years old – they are nice and green but have zero fruit. And just a few fruits on the apple trees. I’m going to implement the horse manure fertilizing plan this fall. Is there anything else I can do to increase my chances of having fruit in the summer?

Answer from Pat:
When fruit trees fail to bear the reasons are usually one of three common causes: The first is planting and trying to grow trees not adapted to the region in which one lives. For example, there are no conventional cherry trees that bear edible fruit that are adapted to mild-winter Mediterranean climates, if that is where you live. The best home-garden Southern California nectarine is ‘Panamint’, but even it sometimes fails to bear on years when winters are warm and mild. Peaches and plums are also highly regional. Refer to the lists in Sunset Western Garden Book to make sure the varieties you are growing are adapted to your particular climate zone. It is possible also to plant a variety that is adapted to a mild climate but then a cold winter can freeze the flowers if they open at the wrong time.

Secondly, your trees are still young and might not have been pruned properly to bear a crop. Overly harsh winter pruning followed by too much nitrogen fertilizer can result in all leafy growth and little or no fruit. Deciduous fruit trees here require light fertilization only to be applied so it is active just as the flowerbuds open in spring. Also with two year old trees it’s too early yet to know how well they are going to bear. They are still young and your main aim at first should be pruning and training them into a good shape. Refer to pruning manuals for instructions. Each deciduous fruit tree requires different care. (Also please look at what I’ve written on this topic.)

Another reason fruit trees might fail to bear is because there were no bees to pollinate the blossoms when flowers opened, or you might have varieties that require a pollinator and have failed to provide the right one that blooms at the same time. Pesticides, especially Malathion, kill bees. Please read the sections on pollination and hand pollinating fruit on this blog, and please also look in the lists in Sunset Western Garden Book to see if your varieties require a pollinator. Graft the necessary pollinators onto your trees.

Related posts:

1. Vegetable Gardening and Edibles in a New Garden
2. Fruit Trees in Southern California
3. Sunset areas

Question from Alin:

Answer from Pat:
You are correct. I have indeed recommended many plants as bank covers that are native to Australia, South America, the Mediterranean Basin, and South Africa. Many are colorful and easy to grow in California and easy to grow on banks. Some will survive with no irrigation once established, but many California native plants can survive in summer without irrigation. Thank you for suggesting that I provide some ideas for Cailfornia native plants that can be used to control erosion on steep banks. Here are some ideas:

Many varieties of California lilac (Ceonothus) make fine native ground-covers to grow on steep banks in coastal zones. Among the best selections and varieties for this purpose are Ceonothus gloriosus ‘Anchor Bay’; Carmel Creeper (C.g. exaltatus); and C.h.g. ‘Yankee Point’. Other native ground covers good for banks include Matilija poppy (Romneya coulteri), Manzanita (Archtostaphylos), and Monkey flower (Mimulus).

Taller than the above lilac varieties is C. ‘Julia Phelps’, which is particularly stunning planted on a steep bank next to flannel bush (Fremontedendron ‘California Glory.)—Make sure not to water flannel bush in summer. Plant it in fall and just spritz the foliage with a little spray of water in the evening of hot dry days in summer to make the plant feel as if it has been moistened by a light shower or heavy dew. This is enough to get it through the summer. Summer irrigation can kill it.

Other native shrubs that are useful for controlling erosion on steep banks include lemonade berry (Rhus integrifolia), dwarf coyote bush (Baccharis pilularis), Bush anemone (Carpenteria californica), Western redbud (Cercis occidentalis), island bush poppy (Dendromecon harfordii), toyon (Heteromleles arbutifolia), and coffee berry (Rhamnus californica).

Related posts:

1. Plant to Prevent Erosion on a Steep Hillside
2. Colorful Low Shrubs And Trees For Banks
3. Correcting Erosion on a Steep Bank in Encino