Blackberry
Blackberry is found in the wild at various latitudes, also in Poland. Wild blackberry species differ in many features: the number and size of spines on the shoots, the size and shape of the leaves, the color and stiffness of the shoots. Blackberries with stiff stems, besides reproducing from seeds, they reproduce vegetatively in horticulture by root suckers. Creeping blackberries do not produce root suckers, but they can reproduce vegetatively due to the rooting of the tops of the shoots, that touch the ground.
Blackberries are very valuable fruits, because they are rich in fiber, contain calcium, Phosphor, magnesium, they also have provitamin A., vitamin B1, B2, PP, as well as vitamin C.. The fruit is clearly base-forming, rich in potassium and various trace elements, m in. copper.
Blackberry shoots live two years: in the first year, they grow from the root neck of the mother plant, and in the following year they produce side shoots from the buds, ending with an inflorescence, then they become fructified and die after fruiting. Blackberry fruit consists of numerous drupes, as in the case of raspberries strongly integrated with each other and with the flower bottom. The fruit is black in color and is generally covered with an intense waxy coating. The fruits ripen in the second half of August and September.
Blackberry varieties with stiff shoots, they have many thick ones, large spines and are distinguished by low fertility. Cultivars with creeping shoots are more fertile than them, and many of them bear fruit very profusely and have shoots completely devoid of thorns. The disadvantage of these varieties is insufficient frost resistance – they freeze at temperatures below -17 ° C. Blackberry buds can freeze even with less temperature drop, especially when there is a sharp drop in temperature after the warm period, in autumn weather or when there are large temperature fluctuations in the early spring. They need to be protected against frost.
With the appearance of thornless blackberry, interest in this interesting and useful plant has grown..
The first variety introduced to cultivation in Poland in the seventies was Thornlese Evergreen. It is a mutant of the Evergreen variety obtained in 1926 r. This variety had spiky shoots and therefore the Thornless Evergreen produced from it sprouts from the roots, in case of cold shoots up to the base, new adventitious shoots – spiky. Root cuttings are also used to obtain plants with thorny shoots. Shoots of this variety initially grow stiffly, when they are of length 2-3 m, they bend arched, and when they are longer, lie down on the ground. Their length can be as high as 10 m. The leaves are palmate, sharply and deeply cut, very ornamental. This variety bears fruit abundantly. It has low soil requirements. It blooms in mid-June. The fruits ripen in the second half of August and September. They are medium in size, spherical.
A newer variation, which was introduced to the selection of varieties for employee allotment and home gardens, is Thorhfree. Shoots also grow stiff initially, and when they are of length 2-3 m, they bend arched and continue to grow, lie down on the ground. The length of the shoots also comes to 10 m. The leaves are dark green, five-fold, with only serrated leaves. Very fertile. It blooms in the third decade of June, the fruits ripen in the second half of August.
They are big, spherical. Some years, especially in the north of Poland, fruits ripen only at the end of September.
In our climatic conditions, the shoots of both varieties must be covered for the winter in order to protect them from frosty winds.
