These are observations on a 4 year old Rosemary Harkness growing in Montreal zone 4:

The plant is grafted on multiflora from Pickering.
The bud union is planted at least 6" (15 cm) below soil line, northern style.
The plant receives 5-6hrs of sun from June to August. From September onwards it's in full shade.

The plant is not cane hardy in zone 4, regardless the amount of snow. Mine gets covered under 6' (180 cm) of snow every year. It dies to the mulch line.

Compared with Felicia, semi-plena, Sweet Chariot and even Tamora, which have the propensity to waft and fill the garden with fragrance, Rosemary Harkness does so with more modesty.

The flowers were more fragrant in the beginning, But with years I've noticed the fragrance has diminished. The scent is somewhat fruity with a twist.

Indoors, the flowers waft in an ebb and flow motion. I had 2 flowers in a smallish room and I was often surprised by the fragrance.

It is a very healthy plant. No disease in the past 4 years.
Healthy shiny leaves. New growth has purplish hue.
It has two flushes for me. One long one from mid-June to July.
This first flush can be described as a back to back double flush, the first one spectacular, the 2nd one more modest, 3 buds per stem.

The plant takes a break in July & August. It has another flush in mid to late September. This year was the first time it set no flower buds in September.

For those who love orange roses, one of the most beautiful roses....