Generally, lowercase rose types (floribunda rose, ‘Mr. Philby’ hybrid tea rose) unless the name is a proper noun (English roses, Scotch roses) or to avoid confusion (Use Old Garden roses to create a beautiful arrangement.).
Use A–Z as the primary reference for rose names. Names not included there may be confirmed in Dobson and Schneider’s Combined Rose List (a copy is available in the CE reference cabinet) or via a Google search.
Be aware that a growing number of rose names are trademarked plant names, not cultivars. (Trademarked names are noted in the Combined Rose List with ® or ™.) Capitalize them, as you would any other trademark, but do not use registration symbols. Trademarks should not be placed in single quotes. As adjectives, trademarks must come before the plant name.
Rosa ‘Golden Wings’ (cultivar name)
Golden Bouquet rose (trademarked name)
For more information, see Trademarked plants