Rubus caesius 'Dewberry'

[Ex. Co. Durham, England]

Rosaceae: A creeping perennial whose biennial stems bear weak prickles. Found in dry, grassy places but also in fens and dune slacks. The flowers are 2cm across, with five white petals, appearing from June-August. The fruits are blueish black, large segments offer covered in a plum-like bloom. The leaves are trifoliate and toothed. Widespread and locally common across most of the UK. Native to most of Europe, including Britain, from Scandinavia, south and east to Spain, Siberia and Western Asia.

USES:

The fruit can be eaten raw or cooked, they have a delicious flavour, and it is considered to be superior to blackcurrants though the fruit is rather small and consists of just a few drupes. The fruit can be used for making jellies, preserves. The fresh or dried leaves are used as a tea substitute.

Easily grown in a good well-drained loamy soil in sun or semi-shade. This species is a blackberry with biennial stems, it produces a number of new stems each year from the perennial rootstock, these stems fruit in their second year and then die.

GROWING INFORMATION:

Dewberry seeds 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 procedures 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 first require a period of warm pre-treatment and need to be kept in temperatures of 20°C for a period of 10 weeks. During this time make sure that the pre-treatment medium does not dry out at any stage or it will be ineffective!

Next the seeds require a cold period to break the final part of the dormancy, this is easily achieved by placing the bag in the fridge at 4°C for at least 12 weeks. 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 warm and cold pre-treatments have finished and wait for the seedlings to appear.

It has also been found that fluctuating pre-treatment temperatures 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 whole warm and cold process repeated again to enable more seeds to germinate. Fresh seedlings can keep germinating for up to 5 years after the original sowing date.

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 20 and 40cm depending on the time of germination and cultural techniques and developing seedlings are usually trouble free. Growth from the second year onwards will be much stronger -possibly several meters in length. Cut back excessive growth to make replanting easier and to make plant establishment quicker. Allow them to grow for 2 years before planting them in a permanent position.

Easily grown in a moisture retentive but well-drained loamy soil of at least moderate quality.

HARVESTED: 2024

 
APPROX. 45 SEEDS