|Are there thornless roses? What are their names? Will they grow in California?|
|There are indeed thornless roses, and all will grow in full sunshine in your California garden:
'Pacific Serenade' is a deep yellow miniature thornless rose. Growing to 3 ft. (90 cm), 'Pacific Serenade' is an excellent choice for growing in containers. Although the rose is new and does not yet have an ARS rating, Nor'East claims the rose is disease resistant, remains upright, fragrant, and will produce blooms in clusters for lots of color or can be disbudded for cuttable, single-stem flowers.
'Reine des Violettes' is a bit larger rose, growing to 4.5 ft. (1.4 m). This Hybrid Perpetual rose is nearly thornless, remains upright, displays gray-green foliage and deep red-violet blooms. It is rated by those ARS rosarians who grow it at 8.0 ("excellent").
'J.P. Connell' is a white, virtually thornless Shrub rose which grows to 3 ft. (90 cm) high, but spreads to about 5 ft. (1.5 m) wide.
'Mme. Legras de St. Germain' is an Alba rose which produces large cream-white, very double blossoms atop gray-green foliage. Another virtually thornless rose, this beauty grows to 7 ft. (2.1 m) high and almost as wide, and is rated 7.9 (a very high "good").
'Kathleen Harrop' is a light, shell-pink color "sport" of 'Zephirine Drouhin' - both virtually thornless Bourbon roses. Both grow to 10 - 12 ft. (3 - 3.6 m) and can be used as climbing or backdrop roses. 'Zephirine Drouhin' is rated 8.1 ("excellent") by those ARS rosarians who grow it.
'Hippolyte' is a nearly thornless Gallica which blooms in vivid carmine with shades of violet. Although the blooms are small, they come in clusters on 4 - 6 ft. (1.2 - 1.8 m) canes. Although this rose blooms only once, it is well suited for northern gardens where seasons are short.
'Tausendshon' is a R. multiflora cross with a bit of the Hybrid Perpetual 'General Jacqueminot' in its background. Its name means "Thousand Beauties" and its blooms certainly bear up to that name. Flowers are deep rose-pink with at least a third of the center petals a cream-white. The blooms are large, cupped and form in clusters. It grows to about 8 ft. (2.4 m), and is rated an 8.5 ("excellent") by those ARS rosarians who grow it.
'Nevada' is a Species rose that produces pink or apricot buds which open to large, white single blossoms. Sometimes the petals' reverse sided are splashed with carmine. A vigorous grower to 7 ft. (2.1 m), this rose will repeat in the fall with a second heavy flush. It is rated an 8.8 (a very high "excellent") by the ARS.
'Lady Banks Rose' or R. banksiae comes in two "flavors" - white and yellow. This once-blooming species rose can grow quite large in southern climates with mild winters. In fact, the largest rose in the world is a "double" white 'Lady Banks'(R. banksiae banksiae) and covers, at last count, more than 8000 sq. ft. The small size of the blossom is more than made up for by the huge clusters it produces along its thornless stems. The white version is rated 9.5 (an almost-as-high-as-you-can-get "outstanding") and the yellow (R. banksiae lutea) is rated 9.1 ("outstanding").