American Rose Magazine 5(9):185-186 (May-June 1944)
What is an "Everblooming" Climber?
The Brownells,
Little Compton, Rhode Island

The designation "everblooming" implies an ideal for "reblooming" climbers toward which rose hybridizing is rapidly progressing. By inheritance from Rosa chinensis, through cross breeding and selection, many hybrid tea seedlings make rapid growth, and each new stem produces one or more blooms throughout the growing season. We would like to have the climbers rebloom in much the same manner. Climbers usually produce long blind canes from which flowering branches arise the following year. This cane-growth seems to prevent flowering therefrom during the current season and rebloom any season thereafter, even though the reblooming character is in the hereditary constitution of the variety.

The problem that the rose hybridizer faces in seeking to combine the true reblooming character of the hybrid tea class with the once-bloom climbing habit of growth, has been most interesting though somewhat puzzling. Nature has her own way of doing things, and, in seeking them, man is often confounded, and eventually aghast at their simplicity.

While the rose hybridizer cannot successfully combine the true reblooming quality with the ordinary cane-growth of climbers, very satisfactory types may be produced by encouraging the vigorous branching growth of the flowering stems. An illustration of this is the variety Orange Everglow in which these two types of blooming habit are present and segregated. Certain confirmation lies in the fact that if the once-blooming cane-growth is not removed it may by its vigor smother and prevent the establishment of reblooming wood.

The vital point involved is that what we call "once-bloom" and "rebloom" are two different kinds of reproductive growth designated as tallness and dwarfness. The flowers are the same in appearance, but the growth processes are, and in a way remain, separate and independent when combined by hybridizing into one variety. They are influenced by separate and different constitutional factors. The problem is a little befuddled by nature since the once-blooming varieties sometimes flower a second time during the season because of certain environmental conditions, this being a repetition of the once-bloom character. The rebloomer may also flower early in the rose season. It follows that any true cane-growth on either the once-blooming type or on an everblooming climber is a barrier to the expression of the rebloom character.

This phenomenon might be described a little differently. The cellular development of vegetative cane-growth is such that stemmed through that growth no branch can produce the sexual expression of rebloom but may, under certain environment, repeat the once-bloom during the same season, once-bloom and rebloom being influenced by two separate genetical factors. It is believed that exceptions can only be obtained through constitutional variation, such as sports or crossing-over.

It is to be noted, from the foregoing, that once-bloom flowers will not breed everblooming climbers. The theory here expressed seems to be confirmed by experience.

As the rose hybridizers come to recognize these basic facts they will give us reblooming forms that will climb over the tops of the supports we build and bloom as freely as the most profuse varieties.

See also:

How Remontant Climbers Act by Mrs. Thomas Howell Scott

Penzance: Repeat bloom on sweet brier hybrids (1896)