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Pollination

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Our roses and clematis win several awards every year for their beauty, fragrance and hardiness.

Novelties

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Find the rose or clematis that exactly matches the colour, height and look you have in mind for a specific loaction.

Thousands of pollinations

Roses contain both male and female organs in each flower. These are usually self-pollinating and produce seeds that germinate into quite uninteresting rose plants. To avoid self-pollination, all the flower’s anthers are removed at the rose’s bud stage and the immature stigma is allowed to develop slowly under a protective paper bag.

Pollination takes place over several weeks on all the flowers that develop on the selected plants until the planned amount of 15,000 hybrids has been reached. When the stigma has matured, it is pollinated with the selected pollen. The paper bag is placed on the plant again to protect it against unwanted alien cross pollination. With effective pollination, the pollen grains will immediately start to germinate. They compete in their germination and those that germinate the quickest will fertilise the eggs in the ovary of the rose – this race takes approx. six hours. The fertilised flowers develop rosehips, some very few and others up to 25, depending on the variety of rose.

Three months after fertilisation, the rosehips are harvested for temperature-treatment (stratification) in a refrigerator and greenhouse for four months. The seeds are sown in modern greenhouse facilities and cross-pollination will usually result in approx. 70,000-100,000 seeds.

By April, the small new rose plants will be standing like ranks of soldiers. All are genetically different – including the seeds from the same rosehip. While the seed plants continue their development, the best are selected and the poorest discarded.

Of the many seeds, approx. 2,000 varieties are selected. Of these, approximately half will be potted roses. Clematis breeding is carried out in the same way and annually results in approx. 500 new varieties for further testing.

Poulsen Roser A/S ● Kratbjerg 332 ● DK-3480 Fredensborg ● Denmark ● +45 48 48 30 28 ● post@poulsenroser.dk