CONTAINER GARDENING IN THE HIGH DESERT
© 1999 by Siri Amrit Kaur Khalsa
(This article originally appeared in the Fall, 1999 issue of the "OGR & Shrub Gazette", published by the American Rose Society.)
When I decided to grow some roses for the first time about six years ago, I had no idea what I was getting myself into. My husband and I had moved to Albuquerque, New Mexico so that he could attend the University. In order to cut our expenses, we took a position as caretakers at a storage facility. We were given a mobile home in which to live, surrounded by three acres of gravel parking lot, a stone's throw from the freeway. I immediately realized that unless I had some flowers and green things growing around me, I would go nuts. It was about that time that I discovered the Old Garden Roses in the Wayside Gardens catalog, and it has been a long slide into rose addiction ever since.
I quickly discovered that there was very little information out there about growing roses in containers, growing roses in the desert in containers, and growing roses without toxic chemicals. Through trial and lots of error I have found a system that works for me.
Conditions in Albuquerque can be extremely harsh for container gardening. We are at about 5,000 feet of altitude. Our winters often have low temperatures in the single digits, Fahrenheit. On top of that, where my home is located I get freezing, gale-force east canyon winds. My husband and a friend built a windbreak along the east side of the house. We put a lot of the roses behind the windbreak against the wall in the winter. In the spring we remove the windbreak and those roses get morning sun the rest of the year. Spring has hot, dry southwesterly winds that can go on for weeks just as the roses are leafing-out. Early hot spells are followed by late freezes, even into May. Summer is a blast furnace with low humidity and temperatures over 100 degrees. Autumn is Nature's way of apologizing for the rest of the year.
My other main rose-growing area is a west-facing deck that gets full afternoon sun. This poses quite a challenge, because the roots can cook to death in their pots no matter how much I water. Desiccating spring winds can kill a young plant quickly before it has had a chance to develop a strong root system. All the books say that roses need "full sun", but they don't know New Mexico sun! I needed to do something to help reduce transpiration when temperatures rose, the humidity was 5% and the winds blew at 40 miles and hour.
My husband is a wonderful carpenter. He and our son built me a shade lattice roof structure over the deck. The lattice provides about one-third shade, which is just perfect for the roses. On the far (western) edge of the deck I have a long roll of green shade cloth that I can unroll for a vertical shade screen to keep out the worst of the afternoon heat. It reduces the temperatures by at least fifteen degrees. While it is too shady to promote optimal blooms, it does the important job of keeping the roses alive until cooler temperatures arrive. Then I take it down again.
I have found that the best soil mixture for my roses is a mixture of two parts compost, one part coarse sand, and one part small pumice. This is similar to the mixture in the beds of the Albuquerque Rose Garden, and the roses seem to thrive on it. If I don't feel like doing all that mixing I will use a bagged potting soil that has a lot of compost, "forest products" and gritty stuff in it. To either mixture I add Superphosphate and Planters II trace minerals. I really dislike the bagged mixes that are mostly peat with a small amount of Perlite added. It seems that they either dry out too fast or else they stay too wet. My roses have never done well in those soilless mixes.
In order to conserve water, insulate the roots, and create humus in the soil, I mulch heavily with bark or Christmas tree mulch.
I use plastic pots because clay pots are too heavy and dry out too fast. Clay also gets cold in the winter and can crack. Almost all of my roses are ownroot from small mail-order nurseries. I have found that they survive winter in pots better than roses budded onto rootstocks. Most of my pots are from five to ten gallons, with a few larger tubs, and a few smaller for the young plants and smaller minis. Double-potting can insulate the rootballs from the worst of both the cold and the heat. I have also wrapped white shelf paper around the black plastic pots to deflect some of the heat. It's ugly, but keeping the roses alive is my main objective.
The worst pests here are spidermites, aphids and thrips. We get little blackspot, but powdery mildew can be awful at times. For mildew prevention I like to spray sulfur several times in the winter, and in the spring until the temperatures begin to climb. My bag of wettable sulfur dust says that it also controls spidermites, and since I have been using the sulfur I have, indeed, seen far less spidermite damage. Once the daytime highs reach 85 degrees I stop using sulfur, and instead rely on a waterwand, and foliar spraying of liquid kelp or compost tea. A strong blast of water to the undersides of the leaves for five days in a row will get rid of spidermites. Water will also knock down aphids, and if repeated several days in a row, the aphid problem is solved. Washing the leaves with water also seems to remove the powdery mildew spores before they take hold.
I regard thrips as more of an annoyance than a crisis. Thrips damage to my roses has not been that bad, and they usually go away after awhile even if I do nothing. I do believe that the more we spray pesticides, the more we kill off our beneficial insects, and create a dependency on sprays. So I don't spray for thrips, and I don't fret over cosmetic damage.
My happiest "discovery" so far has been foliar spraying of anti-transpirants, such as liquid kelp, fish emulsion/kelp combinations, and compost tea. These products give the roses a real boost in the hottest, most stressful time of the year. They also seal the leaf surfaces to prevent the spread of Powdery Mildew.
My feeding program consists of alternating Fish Emulsion with Alfalfa Tea. I add Alaska Mor-Bloom (0-10-10) to both of these.
My favorite recipe for Alfalfa Tea is:
To a 32-gallon trashcan with a tightly fitting lid, add:
12 cups alfalfa pellets (the kind sold at feed stores, without added salts)
6 cups cottonseed meal (again, available at feed stores)
2 cups Epsom salts
2 cups Alaska Mor-Bloom -OR-
1-2 cups kelp meal instead of Mor-Bloom
Fill the can with water, cover tightly, and let it brew in the sun for about 4 days, until it is foamy on top. Then scoop out about 1 gallon per rosebush, more for big roses, less for minis. I save the sediment in the bottom and refill with water to brew a second batch. Then I keep the sediment mixed up to distribute it when I water the roses with the tea. This tea really stinks, but the roses love it! I start using it after spring pruning to encourage new basal breaks. I feed this tea maybe once a month thereafter during the summer, stopping at least six weeks before our first expected frost date. After I discontinue the tea, I use the 0-10-10 for the rest of the fall. Between the alfalfa tea feedings I feed with fish emulsion. This can be a lot of work, but the roses need frequent feedings since they have to be watered so much in the summer.
A couple of times over the spring and summer I sprinkle very small amounts of kelp meal and trace minerals on my pots, and this seems to help the roses in the heat.
Since I have gone to a strictly organic fertilizing approach, my roses have been incredibly healthy, with not one trace of powdery mildew in the last two years. Since I don't use fungicides in the summer, and other roses in the city are mildewed, I can only attribute this to the alfalfa tea, kelp meal, water wand, and anti-transpirants.
I have learned to love my OGR's and shrubs for their toughness in less-than-ideal conditions. My few Hybrid Teas need to be brought inside on the coldest nights, but not my hardy Portlands and Rugosas. Many of my roses, like Autumn Sunset, Ulrich Brunner Fils, and Jens Munk want to get big and I am just keeping them in pots until I get a real garden. But I do grow some roses of smaller habit that seem to be made for container growing. Some of my favorites are:
Phil's Hot Pink Perpetual Damask, for its' prolific flushes of bloom, incredible fragrance, and obliviousness to heat and cold. It resembles Rose de Rescht and is every bit as fragrant, but the color is clear rose pink rather than fuscia. This may be the rose General Allard.
Sydonie, a Hybrid Perpetual, for its' fragrance, repeat bloom, and perfect "old rose" form. I am a sucker for button eyes, and Sydonie has the most wonderful button eyes.
Charles Rennie MacIntosh, an Austin rose. It has been in a whisky barrel for five years and just gets better and better every year. This is one tough rose!
Lyda Rose, a Hybrid Musk-like small shrub. This rose has a graceful, spreading growth habit. I prune it very lightly, and become dizzy inhaling the delicious fragrance. The flowers are small, single, white with delicate pink edging and reverses. Lyda Rose would look lovely in a Japanese garden.
Souvenir de la Malmaison, loves the heat.
Tamora and Prospero, both small-growing Austins with wonderful fragrance and repeat bloom.
Pink Gruss an Aachen, possibly one of the best roses for container growing. It is a delight.
Marie Pavie, Polyantha, for constant bloom. Both Marie Pavie and Pink Gruss an Aachen are thornless as well!
Heidi, a pink Miniature Moss rose. This rose has a purity of color that I just love. The flowers contrasted with the rich, green foliage, always makes me stop and admire her.
The smartest thing I ever did when I decided to start growing roses was joining the Albuquerque Rose Society. This has to be one of the friendliest and most helpful of all local rose societies. I strongly encourage anyone wanting to grow good roses to join their local rose society.
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