An interesting read, thanks! Wonder if the results would have been different if they had watered the roses til they were established and then stopped.

" shipped from Oxford and planted during late November. The soil had been previously ploughed and rotovated; holes were dug and the bare-root, root -pruned plants let into the holes with a couple of handfuls of local proprietary compost. The plants were heeled in and watered once only. No further irrigation was employed. Straw mulch was employed each summer."

Well established roses will survive here (more coastal than Pomona) on no summer water. I know because I had a broken drip line and a few got zero water this past summer.

Will they bloom? No. Will they look good? No. A thick mulch would certainly help, as well as all-afternoon shade. Still, why go a whole summer with no flowers?

Is greywater irrigation a possibility?

Since the point of an ornamental plant is to look...ornamental, it seems like shooting yourself in the foot not to water them.

Yes. I really think Teas can get along on LITTLE water, once-established. But they really wouldn't do much with NO water.

And not just Teas, either. That's why I've been so skeptical of the "Earthkind" Trials, relating to SoCal. TX gets summer rain. Southern California -- not really.

And of course, there's the issue of when they will bloom.

In our increasingly hot summers, NO WATER would mean there would be little or no bloom. Winter -- as long as the rains don't fail -- there would be plenty of bloom, but for a public garden, that's maybe not enough.

Jeri

I see your point Kippy. Some roses establish less easily than others. I was surprised that any made it with such treatment.

Hoovb, it all goes back to my design concept...using plants that grow and bloom in winter and then become dormant in summer, which is symbolic of the Mediterranean climate. Why do people accept plants like the Liquidambar, which is completely bare in winter? Probably because it's seasonal changes are comfortingly familiar reminders of colder climates. Plants that go dormant in summer can provide symbolic references to the Mediterranean climate. Maybe most roses look hundrum when they are dormant but some, like Safrano and Madame Lambard, make a good display of hips during their summer dormancy. And if people can enjoy these seasonal changes then it becomes much easier to conserve water.

Thanks for your input,

Nate

You're right!

You're right -- of course -- And there are many other examples, as well.

I just think it will take a LONG period of education.

Jeri

Hi Jeri! Yes, it will take a long period of education. The traditional seasonal changes, even though they also have a dormancy period, seem to be automatically assumed to be normal and wholesome.

Trees and shrubs that go dormant in winter often have beautiful lines and/or interesting bark, and in So. California, give the eye that welcome variation from one season to another that many of us appreciate. A sparsely watered rose in summer, alas, is usually not a thing of beauty. Most roses are grown for their flowers, at least in my garden, and every day without flowers is for me a day that is less beautiful than it could be. With global warming and probable future water restrictions, I want to enjoy that beauty for as long as possible, in the present, although of course doing everything possible in the way of mulching year-round to improve the soil and provide protection against the heat, with extra mulch during the heat of summer. It may come to the point where many of us will have fewer roses, but I still treasure the idea of having them bloom as much as possible throughout the year.

Ingrid

Not many plants get by with no water for 6-7 months unless they are natives long adapted to that regimen. Even those typically do it by going dormant.

I don't expect roses to perform with no water whatsoever for that length of time, which is what unirrigated roses would face in my climate. However, I am interested in knowing which roses can get by with an infrequent deep watering, say, a deep watering once a month, or even every third week. By deep watering, I mean 30 minutes of overhead spray. I have a dozen or more established climbers and teas on that program. ( I do give them an extra 10 minute cycle midway between waterings if we get a serious, prolonged heat wave.) Of course they would be happier with more frequent water, but they do okay on that. Note that I reserve this treatment for distant roses on the back fence. The ones up close to the house that I see every day are watered once a week, lush treatment by my standards.

Rosefolly

Does this site have popups every time you want to send a message? Maybe it's just my computer!

Thanks Ingrid and Rosefolly.

There are many different ways to celebrate California and the Medit climate--in my designs I show respect for my clients by putting in plants they truly prefer but I always try to reduce water use in different ways--reducing or eliminating lawns by increasing paving, groundcover, etc and using green-looking, drought resistant plants. Roses only need moderate amounts of water to bloom okay, as Rosefolly points out. I think the pragmatic thing to do for private clients is to think in moderation.

Everyone should be able to do what they like with their gardens. My whole point is that winter is thought of as the time for dormancy, when it often should be summer. Most rose gardens are pruned in Jan or Feb, and put out of commission for 2 months, which makes no sense for Tea roses (and some of their derivatives) because that is their natural blooming period, see the plant breeder Franceschi's observation on Rosa gigantea at the URL--the plant's bloom season is in winter in Santa Barbara (he says).

I'm hoping at some point to put in more unusual gardens for people who are receptive to the symbolic use of dormancy and growth to reflect the climate, e. g., rose hips as a dormancy symbol for summer. The beauty of Tea roses is that they are naturally suited to bloom and grow in winter. Why can't we have a long lustrous winter of blooms and just feel natural about our roses going to sleep in summer, albeit with showy hips or with other structural plants to keep up appearances?

Here is a link that might be useful: Franceschi, F. (1911) Behavior of Alien Plants At Santa Barbara, with Special Regard to their Naturalization and Phenological Phases

I probably already said this in your first thread, but will take the risk of repeating myself.
My Tea roses--in fact, all my roses--after the first year get no water. They all survive, and, when it starts raining again, they start to grow again and resume flowering. Now, some considerations. There are many different kinds of Mediterranean climate: we get about 40" of annual rainfall, have four definite seasons, and have deep, heavy, water-retentive soil. What works for me may well not work in an area with 12" annual rainfall or in a area with shallow or light soil.
About the dormancy that comes with drought. Absolutely, if the roses don't get water they stop blooming. When I got back from Florida in August this year, the garden looked like a battlefield the day after: gray, dusty, and dead. No, I don't want my garden to look like that. Of course, like Ingrid, like everybody, I want to enjoy my garden year round. So, aside from summer watering, what are my options?
I learned about sequential bloom and seasonal interest in my first garden: not that everything blooms for months on end, but that one flowering, or other garden beauty like foliage, is followed by another, so that there's usually something interesting or beautiful going on. Still, in summer there's not much at all in bloom (lavender). But this is the season when shade and garden structure become important, and I can learn something from the classical Italian garden. They were invented to give a cool green space for people to walk. I want trees and shrubs for many reasons: to make the garden handsome even if there's nothing in bloom; to give shade in hot weather; and for practical reasons like holding the ground and supplying organic matter. So, in summer the garden can become green, shady, and architectural. I'm not there yet, but am working on it.
Of course there's the option of not going out in the garden at all, and I exercise this option frequently, when the sun is up for fourteen or sixteen hours and it hasn't rained for weeks. We stay indoors in our cool cave of a living room, or I hang out in whatever shade I can find, especially under the wisteria pergola. I wish I could bring some order into this area, because it could be beautiful with the potted plants, succulents especially.
Melissa
P.S. When I call the garden "architectural" I'm not talking about man-made structures. I mean the play of volumes, masses, and empty areas; the compositions achieved by hedges, grass walks, trees, and shrubs; and the effects of terracing our steep ground. Man-made structures can do a lot for a garden, but ours are all of the crudest kind and serve purely practical ends.

We have hot dry periods here, even in the SE. The teas (which are established) seem to go more dormant than other varieties. I am adding a drip irrigation system to the two beds that I have teas in this winter, so I will see how that works.

I don't mind a short dormant period in late July/August. My roses normally bloom from April - October. This year, I have tons of buds/blooms still, the result of some nice fall rain and moderate temps. The teas are doing especially well now.

Thanks Buford and Melissa. When grown in a long drought some of the older Teas like Safrano and Madame Bravy act exactly like a southern California native and defoliate in summer. They don't look ugly (to me), they just look dormant. Other plants can carry the torch at that point, or you can use their hips as a feature (I know from my lit review Safrano has good hips, don't know about hips on Mme Bravy).

Roses tend to be selected for their characteristics when they are actively growing but for very dry gardens you would have to think about their dormant aspect as well, and not use too many that were duds at that point. A different way of thinking about rose gardens, but it's valid.

Or like Melissa you can follow the Mediterranean tradition and surround your rose garden with evergreen hedges in some kind of formal layout. Or shrubs and trees can be used informally, in some kind of composition that is not dependent on the nearby roses. Then the structure and beauty of the garden is carried forward in the dry summer.

Because of all these factors dormancy doesn't have to look ugly. For me, the medit seasonal changes are romantic and something to look forward to--the summer is golden light and plants waiting for the rain; in the late fall the roses wake up with dramatic purple shoots, the winter is long and lustrous and full of bloom.

!!As long as you have an opportunity to plan it out that way!!!! And some medit gardeners like Melissa also have a winter dormancy to contend with.

Rosefolly said, "Not many plants get by with no water for 6-7 months unless they are natives long adapted to that regimen. Even those typically do it by going dormant."

You are so right! I assisted in my sister's HOA's thoughts of "going native" because they believed "native" meant never watering. What finally got the idea through to those who believed lush, green could be achieved simply by planting "natives" was to point to the dry brush on the hills around them and say, "no water, native". Yes, you can skew the results more toward what you hoped for by careful selection, but very few "natives" look acceptable to modern eyes unless they are frequently groomed and regularly irrigated. Even "ornamentals" such as lavenders, rosemarys, santolinas, salvias, euryops and most other daisy types, look like crap unless they are dead headed, groomed, pruned and kept watered. Otherwise, they look very much like the "native sage brush" all around us on the brown hills here in California.

I just visited Redding to deliver some roses to Lyn. It is very instructive to watch the zone changes as you travel along the state. It is obvious where the rain falls, and where it doesn't. Where there IS rain, things are lush, green, wooded and colorful. Where it doesn't, brown and gray (called fire fodder) predominate. We in the more arid areas can have those results, but that requires irrigation. No depth or type of mulch can substitute for double the rainfall inches, nor for a greater percentage of the year. Thirty-plus inches of rain for nearly half the year makes a tremendous difference when compared to less than half that, mainly delivered in three to four months and very often resulting in tremendous run-off and erosion. Kim

"We in the more arid areas can have those results, but that requires irrigation."

SO VERY TRUE!
And, as our available water supply diminishes, we are going to have to learn to change our ideas about beauty. Where I live, our acquifers are in real jeopardy -- rendering decorative irrigation pretty perilous, long-term. What works where nature provides water isn't going to work here, forever.

I've got a photo of my G-Grandfather's home in TX, taken in 1901. Step-Gramma grew roses, and you can see them, but they are inside a bob-wire fence, and located where dishwater and such could be dumped on them.

Jeri

A re-definition of beauty...what I came up with is "Winter-Green, Summer-Shape" using plants like Euphorbia balsamifera that completely drop their leaves in summer and have an interesting-looking, twisted shape. The species in question, e. g., Ribes speciosum, Euphorbia misera, are more landscaper-friendly than lavenders and sages because they need less pruning, and don't "brown out" if they aren't given water (albeit they won't have any green leaves at all in summer).

Well, back to roses: they could be used as adjuncts to the style, in close-in garden spaces where they could be given extra care. As long as the roses showed winter growth then they would "resonate" with the other species.

raingreen .... how are you defining "medit climate" ? I am guessing that you are referring to a climate with no summer rains ? Am I correct ?

Kim .... did you notice the change in the native vegetation as you came up the mountain ? That's something I watch for every time I go down the mountain to go shopping.

Smiles,
Lyn

Yes ma'am. That's one of the more fascinating facets of travel, Lyn. Watching to see what grows where and how well. There is absolutely no way for me to keep Hosta alive in my climate, yet they were dense, mature, full and in full flower at the hotel by the SF airport yesterday morning. I've always found it interesting watching how the unassisted vegetation changes with the climate. Kim

Kim....

No deer at the SF airport ... 'o)

Smiles,
Lyn

Yes dry summers and rain at the cooler time of year.

Olivier Filippi's Dry Gardening Handbook helps gardeners decide on plant selection if they want to dry garden in a medit climate (no watering in summer). Plant drought hardiness (though it's complicated) is summed up in a "drought code".

Pomona is rated drought code 5; most roses are rated drought code 3(the lower the number, the less intense the summer drought). Drought code 3 is fairly drought resistant. Drought codes are the same thing as "hydric deficit" in the map. The map shows some cities in California (including Redding (drought code 2), LA, San Diego, etc). The drought code is easy to calculate, send me PM if interested.

Here is a link that might be useful: Hydric Deficit Map

So, "Hydric Deficit 5" is a less-intense summer drought?

I see that Santa Barbara is Deficit 5 -- but our immediate area gets markedly less rainfall than Santa Barbara (pioneers here depending in large part on springs, rather than rainfall) so we're probably Deficit 4, or close to it.

Am I understanding correctly that roses can theoretically withstand a drought-code 3 without irrigation???

I think it would depend in some part on the roses measured. (For instance, we know from experience that most of the Austins show definite stress without ample water ...)

Again, this is of course meaning that they probably won't DIE, rather than that they will be beautiful garden plants after 4 or 5 months without water, right?

Like my Step-Great-Grandmother, we save water in containers, and pour it on the roses -- and that helps.

Jeri

An own root Banksiae will withstand water stress much more successfully than many own root types, particularly evergreen roses (Teas, Chinas, HTs, etc.). They are harder wooded and are able to shut down and exist when conditions are terrible. They have tremendous root systems compared to many, even Dr. Huey. When rating commercial roses for any kind of soil and climate performance, what kind of roots they have makes a tremendous difference. Huey is rather extensive and persistent, but even it suffers greatly in heat, aridity and extreme drought.

I have a very large, double white Banksiae in the very loose, very dry, un irrigated slope at the southern side of the rear deck which receives direct, full southern sun about 80% of the time. The ONLY "irrigation" it ever receives is either rain or the extremely infrequent hosing off the deck. I cut it off the deck a month ago and it already has a good fifteen feet of "wands" thrown up on to the deck, both from out side it as well as through the openings between the floor boards. Everything on that slope requires watering except that Banksiae and the volunteer black walnuts and peppers. There is a newer terrace which begins about fifteen feet away from that spot, but in the same exposure. It contains seedlings, the Atmore Lamarque, Reve d'Or, and George Washington Richardson. These MUST be deeply watered weekly if temps are in the eighties or above. That blamed Banksiae was planted there 35 years ago, watered weekly its first year, then left to its own devices. The Myrtus communis compacta in that line was well established when the house was bought in 1975. In all that time, it has only received rain and it is nearly six feet tall and much wider. Until I began planting back there last year, only the three existing roses and one crepe myrtle were irrigated and that was weekly (at most) by the gardener who kept the place trimmed and leaves blown off. Otherwise, there is no irrigation system and no one else dragged a hose around to water.

Lili Marleen, a well established plant in 1975 when the house was bought, has Manetii stock escaping from under it. the Lili Marleen was nearly gone, but the Manetii has inch and a half thick canes exploding in all directions which I'm working back so both can be maintained. Manetii made it all these years on weekly watering and rain.

If the wood is hard and dense enough and the root system sufficiently vigorous, it MAY work with weekly supplementation. Softer wooded types or those whose root systems aren't as invasive, are going to struggle terribly, or outright fail. And this is in the Encino Hills where we get more coastal fogs and generally more rain than many hotter, more inland areas.

This is the Wunderground calendar for Historic Lincoln Park in Pomona showing temps and rainfall for the month. I selected it as the elevation is similar to ours here.

http://www.wunderground.com/history/airport/KFUL/2012/11/19/MonthlyHistory.html#calendar

This is the closest one to here, though it is 200' lower than I am.

http://www.wunderground.com/history/airport/KVNY/2012/11/19/MonthlyHistory.html#calendar

It might be interesting viewing the historic data for the month as it shows comparative heat and precipitation. I know the performance of many plants here in Encino as well as the Santa Clarita area, where I grew over twelve-hundred roses for over eighteen years. I can well imagine what should be expected from them with little to no irrigation there in Pomona. If you select wisely, plant properly and irrigate sufficiently until they are well established, you might well succeed. But, your selections would be better skewed toward Banksiaes, Fortuniana and deciduous, xerophytic species. They possess the extensive, vigorous root systems, harder wood with greater sunburn resistance, and the ability to suspend their activity sufficiently to withstand the extremes in heat and drought with the least damage. Kim

Jeri, it looks to me like the deficit zones cover rather large areas. If Pamona is 5 and we are 5, your probably considered 5 as well.

On the other hand, if we can gather up our damp foggy dew from our roof to the rain gutters and on to the roses, we might both move up to a damper "zone" I am working on cleaning up one area of some of the banana trees that have survived and produced well because they are under the rain gutter. I think I will change the gutter a bit and let some roses enjoy the roof run off. Just a little bit extra water can make a big difference in a plant. Of course having the RIGHT place is the key!

I am also working on a system that mom can dump dish or mop water and have it run under ground and water another bed of roses with out splashing the house etc

Jeri, Olivier Filippi wasn't totally explicit about how he came up with his drought codes. It seems like he did accept plants going dormant as long as they reliably survived the summer. Drought code 3 is less dry-tolerant than drought code 5. Plants rated 5 can be grown reliably in Pomona without irrigation (he's claiming). Sounds like you are in drought code 5 or 6.

He rates roses between drought code 4(Rosa banksiae, as Kim observes, and R. sempervirens) and 2.5 (Rosa brunonii). The majority of roses are drought code 3. Which means in your area you would always have to provide supplemental irrigation for all the species above.

Thanks for all of the information Kim. Aren't the xerophytes like Rosa hemisphaerica, foetida, stellata dormant through the winter? As a designer I'm more interested in the winter active species, e. g., R. minutifolia.

I don't doubt that my climate will fry most roses without watering. The reason that I was so fixated on Teas, though, was because of their ability to go dormant, defoliating upon the drought and waiting for better times. Gertrude Jekyll, speaking of tea roses on the French Riviera: "tea roses...not only bear but enjoy the summer heat and drought, flowering freely in November and December after the autumn rains and pruning" Wouldn't the only problem, in the case of the very-dry grown Tea rose, be sunburn? Which would mean plants should be grown on north facing walls or be provided temporary shade while they were dormant in summer/early fall? Sorry, but I have to ask. And consistent with Gertrude Jekyll's observation, the understock R. odorata has a much stronger ability to go dormant in drought than the other understock types you had mentioned. See attached. I just want to get to the bottom of this--and keep in mind that I don't mind using summer-deciduous plants. I believe Rosa odorata/gigantea are forest plants in their native haunts, which explains the tendency to sunburn.

Kippy, I also always try to think of ways to make things a little moister for plants in dry gardens. I think the drought codes are good because they help us move into the unknown (or previously known and then forgotten) territory of gardening with the rain, but they should be taken with a grain of salt because there are so many different site characteristics, e. g., a big tree which can suck up all of the water or a south facing exposure vs. a north or east facing.

Here is a link that might be useful: Growth and Physiological Responses of Four Rose Rootstocks to Drought Stress

Yes, xerophytic species are deciduous, however, they explode into growth very quickly once the water flows. In mild winters, they can retain much of their foliage and actually push new growth months earlier than they will in colder, drier winters. They actually defoliate much later with water, and remain leafless much shorter times when it's warmer and wetter.

In my experience, Minutifolia doesn't really "like" extremely hot summer temps. When I grew it in Newhall, it flourished with shade from taller plants during the worst of the summer. As long as it remained irrigated (all watering there was over head via hose and oscillating sprinklers), it continued flowering, as did Stellata. I had it planted in the ground there, well mulched with all the horse manure I could schlep. Here, they remain canned. The happiest are those which receive shade from other roses planted in the ground, with the exposed one complaining the most. I water them regularly and they grow and flower as expected.

An extreme part of the sunburn issue here are the Pacific Flathead Borers. Sunscald is an open invitation to these nasties. By the time you usually discover their presence, they're on their way toward the bud union or crown of the plant. Once there, forget saving the plant as they are most often toast. Good cultivation, proper watering and avoiding injuries are the suggested prevention.

Here is a link that might be useful: Flathead Borers

We have lost roses here to sunscald -- and found that the roses which handle that best are those with a lot of foliage. Well, DUH ...

But, listen -- we tried a series of four different roses here, against a low, south-facing retaining wall. The last thing we planted there was the China, 'Louis Phillipe.'

And, Ta-DAH! 'Louis Phillipe' LOVED that spot, and grows like crazy. It slows down on bloom through the summer, but does not defoliate, and doesn't go completely out of bloom.

NOTE: It IS irrigated ... But so were all the ones that died, and it wasn't enough water for them.

So, I would say -- look at Chinas, as well as Teas.

Jeri

Kim, thanks for the borer info. Are you going to make us some super-hybrid R. minutifolia with big flowers that blooms all year?????

Yes Jeri I know I need to look at Chinas!! Workhorses, but often hard work is what you need.

Nope! The only Minutifolia hybrid seedling I've ever raised was with the mini Anytime. It was so highly diseased, it did the only honorable thing and died. Now, find me some Pink Mystery in this country and I'll work on that with Minutifolia. Until then, we'll just have to see what comes from the seed already planted from this past summer created from Minutifolia pollen. Kim