The Columbus Park of Roses consists of Old Garden roses and Modern roses. Old Garden roses were in existence prior to 1867, and Modern roses have been developed since then. 

The Heritage Rose Garden at the east end of the CPOR is where the Old Garden roses are located. Most of these roses bloom once each year, usually in late May and early June. There are some species of Old Garden roses that will bloom again in the fall.

The Formal Rose Garden of the CPOR is devoted to Modern roses. These include Hybrid tea, Grandiflora, Floribunda, Miniature, Miniflora, Polyantha and Shrub roses. While each of these rose groups has a predictable bloom schedule, the primary influence on when and how long roses bloom is the weather — specifically, daily temperature and rainfall.

Cool temperatures such as those the Columbus area is experiencing this spring tend to slow the bloom maturity. For the year, the Columbus area is more that seven inches above the normal rainfall, but growing conditions have been slowed by cool spring temperatures. 

Peak bloom in the Formal Rose Garden is usually the second week of June. Blooms continue all summer but not at the same abundance as in June. Much depends on the Columbus weather during the summer — both rainfall and temperatures. 

If we experience normal or above normal daytime temperatures for the remainder of May and into June, the Modern rose bloom at the CPOR probably will be ten days to two weeks later than usual. Above normal temperatures during the summer months will tend to increase the frequency of bloom if rainfall is average. Below average rainfall and hot temperatures will cause the roses to reduce their frequency of bloom. 

 So how frequently do Modern roses bloom? Hybrid teas, depending on the age of the plant, will bloom on a 42- to 56-day schedule — the newer bush earlier, the older bush later. Grandifloras, a cross between Hybrid tea and Floribunda, will have multiple blooms per stem and will bloom on a schedule similar to Hybrid tea roses. Floribunda roses have multiple blooms per stem and tend to bloom on a 35- to 42-day schedule.

Miniature and Miniflora roses will bloom about every 35-42 days.  Shrub roses bloom continuously throughout the growing season with the spent bloom being pushed off the bush by new growth.

As temperatures become cooler in the fall, we should be treated to another peak bloom of the Formal Rose Garden in mid-September.

Tip: Throughout the CPOR, these abbreviations on plant labels denote the type of rose:

    FL – Floribunda                 POL – Polyantha

    GR – Grandiflora               SH = Shrub

    HT – Hybrid tea

Written by William E. Riddle, PhD. and member of the Rose Foundation