Article (newsletter)  (Jul 2012)  Page(s) 34.  
 
My own personal favorite hybrid from Michael Horvath is Thor, a rich rose crimson bloom of modest size, but bright promise. It blooms late and then blooms again in our extended bloom season in California, and always catches my attention

Book  (2007)  
 
'Thor' Hybrid Setigera, dark red, Horvath. PP387. (Alpha x R. xanthina) x Pres. Coolidge. Includes description.

Book  (1994)  Page(s) 148.  Includes photo(s).

Book  (Apr 1993)  Page(s) 604.  
 
Thor Large-flowered Climber, 1940, ('Alpha' x R. xanthina) x 'Pres. Coolidge'; Horvath. Description.

Book  (1993)  Page(s) 52.  
 
The Evolution of Climbing Roses
Stephen Scanniello
A man by the name of Horvath started working with roses in New England in the early 20th century and eventually retired in Mentor, Ohio. He bred some roses using R. setigera, including one of the lesser known red climbing roses called 'Thor'. We have 'Thor' in the Brooklyn Botanic Garden and we are the only ones I know of that have it. Again, people probably do not grow it any more because it only blooms once a season. (This is especially true now that we have 'Blaze', which supposedly blooms all summer.) 'Thor' has large, scarlet red flowers and an incredible disease resistance, which it definitely inherited from the Prairie Rose.

Book  (1955)  Page(s) 54.  
 
Thor (1940). LC. Ovoid bud and 4- to 6-inch very double, dark-red flowers (rather like 'Crimson Glory'). They open slowly and do not discolor with age. Plant this on your house and near a much-used door for six weeks of scent and beauty, starting late May. Foot-long stems on vigorous plants 10 to 30 feet, even in some cold climates, and without protection. Large, leathery, truly-resistant foliage. There is nothing to touch 'Thor' among dark reds, but it is a once-bloomer, though over a long period. Needs protection in some colder regions but all 'Thor's seem variable as to height and cold-tolerance. In Philadelphia, 'Thor' develops a trunk as big as a well-grown peach tree. Rich damask fragrance. I love it!

Book  (1949)  Page(s) 165.  
 
Karl P. Jones. Modern Hardy Climbers in New England.
M. H. Horvath, Mentor, Ohio, Setigera hybrids (except 'Thor').....
Thor 1940. Hybrid Xanthina. Vigorous; 15 ft; hardy; tremendous, double, dark crimson flowers; the best Horvath rose and the best hardy red climber.

Book  (1945)  Page(s) 221.  
 
Proof of the Pudding: growers' reports indicate that is takes a few years to establish.

Book  (1944)  Page(s) 223.  
 
Proof of the Pudding reviews vary wildly: from "unnecessary" to "tops among the red LC roses."

Magazine  (Dec 1943)  Page(s) vol. 5, no. 6, pp. 119-120.  
 
The Recent Horvath Climbers
R. E. Shepherd, Medina, Ohio
Thor is probably the most attractive of all when it blooms but it is, unfortunately, a sparse bloomer and freezes back badly. A long-pointed bud opens up into a very large, double, intensely fragrant, crimson blossom on a long stem that is equaled by few Hybrid Teas. This rose deserves careful winter protection so as to preserve all its canes. In addition to the Setigera, Wichuraiana and Hybrid Tea strains which are found in most of the Horvath roses R. xanthina is also represented.