Commercially available

16 favorite votes.  

Deep yellow Hybrid Tea.
Registration name: Isobel Harkness
Exhibition name: Isobel Harkness

Bred by Albert Norman (United Kingdom, before 1950).
Introduced in United Kingdom by R Harkness & Co. Ltd. in 1957 as 'Isobel Harkness'.
Introduced in Australia by Hazlewood Bros. Pty. Ltd. in 1958 as 'Isobel Harkness'.

Hybrid Tea.  

Deep yellow.  Moderate, tea fragrance.  28 to 34 petals.  Average diameter 4.5".  Large, full (26-40 petals), borne mostly solitary, in small clusters, high-centered to cupped bloom form.  Blooms in flushes throughout the season.  Medium, pointed, ovoid buds.  

Bushy, upright, well-branched.  Medium, semi-glossy, dark green, leathery foliage.  5 to 7 leaflets.  

Height: 2' to 30" (60 to 75cm).  Width: 18" (45cm).

USDA zone 7b and warmer.  Disease susceptibility: susceptible to blackspot , susceptible to Mildew.  Spring Pruning: Remove old canes and dead or diseased wood and cut back canes that cross. In warmer climates, cut back the remaining canes by about one-third. In colder areas, you'll probably find you'll have to prune a little more than that.  Requires spring freeze protection (see glossary - Spring freeze protection) .  

United States - Patent No: PP 1,650  on  8 Oct 1957   VIEW USPTO PATENT
Application No: 620,779  on  6 Nov 1956