From May to October 2022, we monitored the growth, flowering and remontant flowering of blue tea hybrid roses planted in the upper rosarium of the Arboretum Volcji Potok. We observed the following blue rose cultivars: 'Mainzer Fastnacht', 'Charles de Gaulle', 'Blue Girl', 'Tarde Gris', 'Nil Bleu', 'Moody Blue' and 'Claude Brasseur'. We were mainly interested in the generative development of this group of roses, but also in individual cultivars. Sampling was done once a week, so a total of 23 measurements were performed. Initially, we focused on the number of shoots of each plant and the height of the plants. Then we observed the flowers and flowering throughout the flowering period. During the flowering period, we focused on only five of the seven cultivars. The selected cultivars were marked and senescent flowers were left on some shoots or removed on other. Differences among cultivars were observed in growth as well as in flowering pattern and flowering time. The cultivar 'Charles de Gaulle' developed the most shoots. The highest of the observed cultivars was the cultivar 'Moody Blue', which also produced most flowers during the season. The cultivar 'Blue Girl' had the largest flower diameter. Blue hybrid tea roses reached their peak flowering in the month of July. There were clear differences in flowering habits among cultivars 'Mainzer Fastnacht', 'Charles de Gaulle' and 'Blue Girl' abscised the senescent flowers. Contrary, hips developed in 'Tarde Gris' and 'Moody Blue'. Removal of the flowers prolonged flowering of different cultivars.
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