Collecting roses from abandoned gardens of Northern California is a rewarding pasttime. It all started when I was asked if I could identify a 12-foot tall rose that was growing near a house located in western Marin County that dates from the 1920's. It was sort of like a china but sort of like a bourbon. I collected and propagated cuttings and scoured Vintage Gardens until I settled on 'Gruss an Teplitz' as a likely match -- unusual, since 'Gruss an Teplitz' is most often a 4 foot plant. This plant was very mature and had been pruned by continual deer grazing. It has sadly been destroyed. But I have plants from the original!
Since then, I have collected and tried to identify a number of roses from the northern Bay Area.
High resolution digital images can be very helpful in identifying collected roses. The key identifying characteristics include foliage and stipules, armature, close-ups of sepals, receptacle, and pedicel, scent, bloom and growth habit, the latter two being the most variable. I also believe that each rose has a "look" or overall quality that can sometimes be captured in words, sometimes with the camera. Whole-plant shots are essential for conveying a sense of the entire rose.
A study name is assigned to each collected rose until its identify is known. That name is shown in quotation marks, such as "Melanie's Cochet." Known cultivars are shown in single quotation marks, such as 'Jaune Desprez.'
My collection of web pages on these found roses is as follows:
"Tam Glow," probably 'Desprez a Fleurs Jaunes
"Old Town Novato Hybrid Perpetual"
As helpful as pictures can be, color images will never look the same on different computers unless great care is taken to calibrate displays and embed color profiles. Even with the most advanced camera, an image viewed on an old display may never show the color and detail recorded.
Knowing what to photograph is half the battle. Start with the ARS collection of short articles on the botany of the rose.
Familiarity with botanical nomenclature is no longer a barrier, as an excellent handbook has been published: Field Report Of Rose Characteristics, by Judy Dean, Lynne Storm and Bev Vierra. Copies are available for purchase. Contact the authors by email, by fax at (209) 754-4089, or by mail at P. O. Box 336, Rail Road Flat, CA 95248.
A frustrating fact of collecting roses is that the overwhelming majority are common cultivars or rootstocks. The common cultivars like 'Climbing Cecile Brunner' are easily identified after a few encounters. The rootstocks are more challenging, as many are once-blooming. A passing familiarly with 'Rosa fortuniana,' 'Gloire des Rosomanes,' and 'Rosa manetti' will make the job easier. I am collecting images of common rootstocks and will post web pages as time permits.
The steps are well-known but easy to ignore, to the peril of the rose. Consider every abandoned rose to be endangered. Remodeling and ignorant gardeners are the greatest threats. Therefore, the first step is to collect cuttings for propagation. Take a variety of sizes of wood, from softwood to hardwood. If possible, dig up a sucker. Do everything you can to propagate that rose.
The next step is to photograph the rose and all its identifying parts. This can take several sessions, especially when capturing the rose in different seasons is involved. If possible, publish a web page with the images. Try to track down the owner of the rose. Determine the age of the building.
Review your own rose resources to arrive at a likely class. Most teas look like teas. Most species look like nothing else you're familiar with. Note whether the bloom repeats. Look through books with good color plates. This can be easy or it can be hard, depending on the bloom form and color. Reds, crimson and dark mauve photograph and print rather badly. You have to see it in person. But if your bloom shares the color of a well-known cultivar, it is very helpful to identify the shading relative to a well-known rose.
If at all possible, take good quality blooms to a large rose collection near you and compare it to known cultivars. Also, if your propagation efforts are successful, take a small plant in bloom with you to the large rose collection, so you can compare the parts in detail. Offer small plants to rosarians with large collections to facilitate their comparisons.
If it is a good rose, spread the rose around . Make is available to Heritage Roses Groups and to nurseries that specialize in older roses. Remember: there are close to 10,000 cultivars and species. It's a large but finite task.
Be prepared for unreliable identifications. I've found that rose lovers vary enormously in their ability to know one when they see one. In addition to lumpers and splitters, there are many whose impressions are invalid largely because their climates are so different. On the other hand, there is a handful of rosarians who have seen thousands of roses and have the kind of memory to recall their differences and similarities. Hunt down these rosarians and without making a pest of yourself, try to present your found rose for identification with a plant, if possible.