Sustainable Roses for Colorado

Roses are certainly one of the world’s most beloved flowers, and yet many people have given up on them because they have gotten the reputation of needing frequent spraying, feeding and fussing. They got this reputation because for decades, hybrid tea and floribunda roses were bred mostly for special colors, a particular flower form and repeat flowering. Their value was judged more for the exhibition table than for the garden. Now, as more people have become aware of the dangers of pesticides and as the trend has moved to “care-free” shrub roses for the garden, rose breeding has shifted in the last ten years towards more sustainability. Now Texas A&M has a program to test and promote “Earth Kind Roses”, and the rose “Knock Out” has recently taken the rose world by storm, not because it is such a beautiful flower, but because it repeats so well and requires no disease control. Even I, who am mostly interested in xeriscape, natives and Colorado-adapted plants, have come to specialize also in roses because I have been won over by more than a hundred varieties that measure up to my strict requirements for Colorado sustainability.There can be no objective standards for sustainability since all gardeners have different standards, different gardens and varying time and effort available for gardening. But I will offer one approach. To begin with, a sustainable rose shouldn’t act like an annual. Maybe a hundred years lifespan is a bit much to expect, but I think a sustainable rose should perform well for at least ten years.

Secondly, a sustainable rose should be resistant to diseases and have few pest problems. We gardeners should not have to put on a protective suit and spray poisons every 3 or 4 weeks to have nice roses. I think we shouldn’t have to spray more than one or two (maybe 3) times a year, and then we should only spray with water or a mild, non-toxic type of spray. We are fortunate in Colorado to have low humidity and therefore fewer fungus diseases. And more and more varieties are available that are disease resistant.

Another quality of a sustainable rose is that it should be a strong plant that doesn’t need to be pumped up every few weeks with a chemical fertilizer. Chemical fertilizers can be harmful to our soil life and can induce pest and disease problems because fast growth leads to soft tissues; and as the price of petroleum goes up, so will the price of petroleum-derived fertilizers. At Harlequin’s Gardens nursery, we feed our display roses twice a year with a good quality organic fertilizer. Wild (Species) roses don’t need feeding, and the spring-only bloomers only need one feeding a year. Repeat-blooming roses perform better when they are fed twice a year.

A sustainable rose should be able to survive difficult conditions and still perform reasonably well. In Colorado that means a rose has to be able to handle wind, heavy clay and lean soils, some drought, heat, intense ultraviolet radiation, and rapid temperature changes. Many roses that do well in other parts of the country will not pass these tests. There are, however, roses growing in cemeteries and alleys that have survived here for decades, others that have persevered through wars and neglect since the Middle Ages, and also modern shrub roses that thrive here. Of course, what is sustainable and what a rose can endure is relative to the particular location and to the amount of care the gardener wants to give.

And the last characteristic of a sustainable rose is that it must be cold hardy. Many Hybrid Tea and Floribunda roses that are hardy enough for the East and West Coast and the South, won’t pass the ten year test in Colorado, but a few will. And beware the “hardy to Zone 5” promise, because many companies and authors that are unsure of hardiness will say “Zone 5”. Even if a rose will survive 20 below zero, survival depends on when the freeze comes. If a rose has gone dormant and has acclimated to cold temperatures, it is ready to handle a deep freeze. But if the rose is still growing and blooming late in the fall (like we love to see in the Hybrid Teas and Floribundas), or if it begins growing too early in the spring, then our rapidly changing Colorado temperatures can cause considerable die-back or even death.

This brings up the subject of own-root roses. Most of the Hybrid Tea and Floribunda roses that are available commercially are grafted. A single bud from a rose is grafted onto the stem of a seedling rose. This quickly produces a rose for sale, but has numerous drawbacks in terms of sustainability. The graft union is the most cold-sensitive part of the plant, so if it freezes and the upper rose dies, only the root-stock will come up in the spring, not the rose you bought. Also when the entire plant grows from one stem, it cannot renew itself from the root if the stem gets damaged or diseased or gets too old. However if a rose is grown from a cutting and produces its own roots, then it can renew itself possibly for a hundred years. It has more resistance to cold, it generally produces more flowers because it has multiple stems coming from the root, and if it should die back to the ground or get accidently cut off, the variety you bought will sprout from the root. It used to be hard to find own-root roses, but by gardeners’ demand, they are becoming more common. Nearly all Canadian-bred roses are produced on their own roots, because Agriculture Canada has done field trials that prove the higher success rates of own-root roses in cold climates.

Now I would like to give a few examples of roses that are sustainable in Colorado. There are several species of roses that are native to Colorado including Rosa woodsii and Rosa acicularis, but even these need proper siting and/or some water. And truthfully, though species roses are beautiful, many survive by suckering aggressively so are mostly valuable for wildlife areas, the back corner and for bank stabilization. There are other species roses that are well adapted to Colorado, like Rosa eglanteria and Rosa glauca. Rosa glauca, the Redleaf Rose, may seed a little, but it does not sucker aggressively. It has a high American Rose Society rating because it looks good in all seasons. Foremost is its foliage which is a very unusual and beautiful reddish-purple all season long. The spring blooms are small, mauve flowers and following them are copious red hips that last into winter and are showy against the snow. It will grow 5—5′ or a little bigger, is tolerant of poor soil, shade and some drought.

Also sustainable are many of the heirloom roses. The Gallicas can sucker like a wild rose, but usually not as aggressively. They would be my choice to plant by a grave stone, since their suckering can help them evade lawn mowers and herbicides. One of my favorites is Complicata. It is a 7—7′ shrub with long arching canes and large 4″ bright pink single flowers. Yes, it only blooms in the spring, but I pair mine with an old-fashioned Mockorange, and when they bloom together, the effect is stunning. It appreciates the little care I give it, but could undoubtedly survive on its own. Other heirlooms that ask little and give a lot are the Alba roses, like Felicite Parmentier; the Damasks, like Madame Hardy; the Mosses like William Lobb; and the ferny-leafed roses like Father Hugo. Don’t discount these sustainable beauties, just because they are only spring blooming; they are often tougher than the repeaters.

There are also heirloom roses that repeat their flowering and are sustainable. One of these is Sydonie. It is a vigorous 5—6′ shrub with very double medium pink flowers that are very fragrant. It is hardy and has a very reliable and profuse repeat bloom. (It was said to be the favorite rose of Dr. William Campbell, who founded the High Country Rosarium). Others include Rose de Rescht, Marchesa Boccella and Stanwell Perpetual.

The early climbing roses were the ramblers which, though almost all bloom only in the spring, make up for it with huge volumes of blooms. One of these is Paul’s Himalayan Musk. I warn people that it has vicious hooked thorns and covers trees and small buildings, but the pendulous clusters of sweetly fragrant lavender-pink blossoms and the romance of it makes them ignore my warnings. I get to suffer through pruning the one pictured, which overwhelms the apple tree at our house where it stops traffic when in bloom. Francis E. Lester and Lawrence Johnston are also reliable ramblers.

In the group called Shrub Roses, there are many that are sustainable. One of the oldest and best in that category is Seafoam. It grows 3′ high and 4′ wide and has small double white flowers that repeat all season. It is very tough and tolerates difficult conditions well. During the drought of 2002, I saw one in a median strip where nearly everything else had died, and Seafoam was still blooming. Golden Wings and Linda Campbell are other sustainable shrub roses.

The Canadian Roses are classified as shrub roses, but we give them a separated category. They were bred in Canada to be repeat flowering, disease resistant and very cold hardy to at least Zone 3. Two years ago when winter conditions caused many roses to die back, the Canadians had little damage. In particular, most of the best climbing roses for Colorado are Canadian Roses. Two favorites are John Cabot, growing 8—10′ with orchid pink flowers, and Henry Kelsey, growing 6—8′ with red semi-double blooms which fade to a pink-red. Both tolerate some shade, poor soil and stingy watering. Other good Canadian roses are Morden Blush, Winnepeg Parks, John Davis and Morden Sunrise.

David Austin’s English Roses are neither the hardiest, nor the most disease resistant, but on their own roots, many have performed very well in Colorado. They have really beautiful flowers and are often wonderfully fragrant and most repeat very well, so they are worth a little extra work. We have been growing Abraham Darby at the Boulder-Dushanbe Teahouse for 8 years very successfully. It makes a dense shrub 5′ tall and wide with 4—5″ voluptuous double flowers that are a soft-pink shading to apricot in the center. The fragrance is a strong old rose mixed with a delicious fruitiness. It has excellent repeat bloom and has proved a strong performer. Golden Celebration, Jude the Obscure, Wise Portia, Wenlock and others have done well here.

Like the native roses, the “Found Roses” have survived decades of Colorado’s trials by fire and ice. These are roses salvaged from cemeteries, alleys and old homesteads, which are lost to commerce, obscure or unknown. Most only bloom in the spring, but have proved their sustainability and worth. One of these is Desiree Parmentier. It is found in many local communities, growing 4′ high and up to 6′ wide. The medium pink blooms are very double with a green eye, and are deeply and powerfully fragrant with old rose perfume. It may only bloom for 4 weeks but tolerates poor soil, drought, considerable shade and is completely winter hardy. It does sucker a little, and you may think “Oh, I don’t want a roses that sucker, they are a nuisance.” And you may be right. But suckering is a very sustaining strategy. For example, if the roots find more water east of the original plant, the sucker that comes up on the east side will prosper and move the plant in a more sustainable direction. Other enduring “Found Roses” are “Banshee”, “Fairmount Proserpine”, and “Pine Street Tricolor”.

These are but a few of the roses that can glorify our gardens sustainably. They may be a little more trouble than hardwood shrubs, but their other qualities reward us for our efforts. Roses grow quickly and recover from damage quickly, their beauty can touch our hearts, their fragrance can melt into our soul, and many can flower repeatedly. Now we can find these qualities in sustainable roses that are easier to maintain and whose care is kinder to our Earth.