Rosaceae: A erect, deciduous shrub, like the more common R. tomentosa ‘Harsh Downy-rose’, apart from the narrower thorns and smaller darker flowers. Found mainly on limestone soils in north of the UK. Native to Europe, including Britain, from Scandinavia south and east to France, Poland and Switzerland.
The fruit can be used raw or cooked, they are rich in vitamin C, but there is only a thin layer of flesh surrounding the many seeds. The seeds are a good source of vitamin E, they can be ground into a powder and mixed with flour or added to other foods as a supplement. Be sure to remove the seed hairs!
The fruit of many members of this genus is a very rich source of vitamins and minerals, especially in vitamins A, C and E, flavonoids and other bio-active compounds. It is also a fairly good source of essential fatty acids, which is unusual for a fruit. It is being investigated as a food that can reduce the incidence of cancer and as a means of halting or reversing the growth of cancers.
Seeds of the Rugosa Rose have a deep dormancy within them, this requires a degree of patience to overcome and it is usually quite easy to get high levels of germination if the correct methods are followed.
First prepare a free draining substrate into which the seeds are to be mixed, this can be a 50/50 mixture of compost and sharp sand, or perlite, vermiculite. The chosen substrate needs to be moist (but not wet), if you can squeeze water out of it with your hand it is too wet and your seeds may drown and die. Mix the seeds into the substrate, making sure that there is enough volume of material to keep the seeds separated. Place the seed mixture into a clear plastic bag (freezer bags, especially zip-lock bags are very useful for this -provided a little gap is left in the seal for air exchange) If it is not a zip-lock type bag it needs to be loosely tied. Then write the date on the bag so that you know when the pre-treatment was started.
The seeds of this species require a cold period to break the dormancy that is within the seeds. This dormancy is there to prevent the seed from germinating during the autumn and winter when conditions outside would be unsuitable for growth. The breaking of this is easily achieved by placing the prepared bag of seeds in the fridge at (4°C) for a period of between 12 and 16 weeks. During this time make sure that the pre-treatment medium does not dry out at any stage or it will be ineffective!
It is quite possible for the seeds to germinate in the bag at these temperatures when they are ready to do so, if they do, just remove them from the bag and carefully plant them up. When the period of pre-treatment has finished the seed should be ready to be planted. Small quantities can be sown in pots or seed trays filled with a good quality compost and cover them with a thin layer of compost no more than 1cm deep. For larger quantities it is easiest to sow the seeds in a well-prepared seedbed outdoors once the pre-treatment has finished and wait for the seedlings to appear.
It has also been found that fluctuating pre-treatment temperatures that mimic the natural cycle can give the best germination results and I have myself had excellent results by keeping the mixed seeds in a cold shed through the winter for the cold stage of their pre-treatment and allowing the temperature to fluctuate naturally. Ungerminated seeds can have the cold pre-treatment process repeated to enable more seeds to germinate.
Do not expose newly sown seeds to high temperatures (above 25°C). Keep the seedlings well-watered and weed free. Growth in the first year is usually between 15 - 30cm depending on the time of germination and cultural techniques and developing seedlings are usually trouble free. Allow them to grow for 1 - 2 years before planting them in a permanent position.