For most Russians, cranberry is a low-growing shrub with smallish and sour berries, growing naturally in large quantities on tussocks of sphagnum bogs and in damp deciduous woodlands, which is why this species is called swamp cranberry, or, scientifically, Oxycoccus palustris.
It is a creeping shrub from the lingonberry family with shoots 10–20 cm long. The leaves are small, ovate, with a pointed tip. The flowers are pink-red, they are collected in a brush on the stalks. Cranberry blooms in May – June, ripens in August – September.
Fruits of marsh cranberries are globular, dark red or crimson in color, weighing 0.5-1.9 grams. The pulp of the fruit is juicy and sour. The fruits keep well under the snow until spring. At the same time, they not only do not lose their useful qualities, but become sweeter. And they are preserved thanks to a natural preservative - benzoic acid.
Large cranberries (Oxycoccus macrocarpus) in our country, it was introduced into the culture long ago, although the first industrial plantations of it were laid in the United States back in 1812, now it is one of the leading berry crops there. Currently, there are more than 200 varieties of this cranberry.
At the end of the 19th century, this cranberry successfully grew in the St. Petersburg Botanical Garden, but after the revolution, not a trace of it remained. And now in Russia she is experiencing a rebirth.
Large-fruited American cranberries are distinguished by a more powerful development of shrubs. It has creeping shoots 50 to 150 cm long and more, from which numerous fruiting erect shoots 15–20 cm high extend. Creeping shoots in places of contact with the ground easily form adventitious roots. A clear division of erect and creeping shoots is the most important difference between large-fruited cranberries and marsh cranberries.
It blooms from the second half of June to early July, i.e. 2-3 weeks later than marsh cranberry. In the middle lane, vegetative shoots freeze slightly, but everything is quickly restored.
Its berries are very large, round to pear-shaped in shape, light red to dark purple in color. The size of these berries is especially impressive, their diameter reaches 2 cm, so they can be mistaken for a cherry. And in terms of yield, it is far ahead of its Russian "relative". By the way, varieties of large-fruited cranberries differ noticeably among themselves in the shape, color and size of the fruit.
Winter hardiness of large-fruited cranberries is lower than our marsh, because it formed in warmer climates. But under the snow cover, it can withstand frosts down to -20-25 ° C. But it is better to cover it with leaves or spruce branches in late autumn in case there is little snow. For the same reason, only early-ripening varieties of large-fruited cranberries should be grown so that the berries have time to ripen, and the plants - to prepare for winter.
Cranberries (both marsh and large-fruited) have a rich chemical composition and a wide range of medicinal uses. It is an excellent antiseptic; it has a stronger effect on Vibrio cholerae than lime water and a 5% solution of carbolic acid. Cranberries have long been considered an anti-cancer agent by the people.
Cranberry juice relieves thirst in malaria, relieves sore throat, flu, cough, urolithiasis and inflammation of the urinary tract.
When deciding to start a cranberry plantation, one must remember that cranberries are a durable plant. And although in the third year it will create a solid carpet, and in the fourth year it will begin to bear fruit, it will grow on the site for many decades. Therefore, you need to think in advance how this northern beauty will be combined with other garden plants.
Cranberries are planted in early spring, as soon as the soil thaws. It can be grown on any soil, even clayey. But for this you first need to prepare a special "peat" bed. The place for it must be chosen open, sunny, located at the very bottom of the site close to the water.There they dig a trench of the required length, 1.5 meters wide, 0.5 meters deep; crushed stone, broken brick, etc. are placed on the bottom with a layer of 5–7 cm. If the soil is light sandy, then first a plastic wrap is placed on the bottom. Then the trench is filled with high-moor sphagnum sour peat in pure form or with the addition of sand in a ratio of 3: 1, abundantly wetting and mixing this soil, then it is tamped.
It should not be forgotten that the cultivation of cranberries requires acidic soils (pH 3.5-4.5). Therefore, if you have added sand, leaf or coniferous litter to the peat, then this mixture must be watered, after having acidified the water with citric, oxalic, malic or acetic acid. If the site is located on a peat bog, then cranberries can be grown without special soil preparation. It is advisable to lay tarred boards, slate, roofing material or at least a double layer of plastic wrap on the walls before filling the trench so that perennial rhizome weeds do not penetrate the cranberry bed.
After the peat has settled, the edges of the trench are fixed with a croaker, boards, slate so that they rise 5–7 cm above the soil level and do not allow the heavier soil to slide into the trench. Usually, before planting, the peat is covered with a layer of coarse river sand 3-4 cm thick.
Some experts argue that swamp cranberries grow in culture and in poor, light and moist soils. It works best at a groundwater level of 35–40 cm, and with sufficient and regular watering, even at a groundwater level of 50–70 cm.
On such a bed, you can grow both our marsh cranberries and American large-fruited. To do this, in a cranberry meadow, select plants with large berries and cut branches 15–20 cm long from them. Dig the seedlings into damp ground and plant them on a peat bed in early spring.
Large-fruited cranberries are propagated by erect shoots, which root more easily than creeping shoots. Cuttings 15–20 cm long are taken from plants in early spring or late autumn. Cuttings from the initial part of the shoot take root better.
Swamp cranberries are planted in three rows on a "peat" bed, and large-fruited in two rows of 2-3 plants in one hole. The distance between the plants in the first case is 15–20 cm, in the second - 25–30 cm. The petioles are planted directly into the prepared soil to a depth of 11–12 cm. The tops of the cutting 2–3 cm long are left above the soil surface.
After planting, the plants should be watered abundantly and the soil should be constantly kept moist, especially in the first month after planting. Too much waterlogging of the soil is also harmful.
It is important that the seedlings do not overgrow in the first summer during rooting. To keep moisture in the soil, it is better to cover the bed with bog moss, which remains wet for a long time. However, when the moss has already been removed, the topsoil for the winter can be covered with a layer of coarse river sand (5–6 cm). In early spring, it will protect the soil from sudden temperature fluctuations at night and during the day, adversely affecting the rooting of large-fruited cranberries.
Large-fruited cranberries are easy to propagate as green cuttings in greenhouses. For this, during the period of intensive plant growth in June-July, cuttings 5–7 cm long are harvested and planted according to the 3x6 cm scheme, leaving one leaf above the surface. By the way, cranberries reproduce well by seeds.
It is necessary to feed the cranberries carefully, as they do not like excess fertilizers. 5 g of urea, 15–20 g of superphosphate and 10 g of potassium sulfate are added to 1 square meter of "peat" beds, distributing them in equal shares over three doses. At the same time, fertilizers containing nitrogen can be applied to the soil only until the end of July, and fertilizers containing chlorine should not be applied at all, replacing them with potassium sulfate.
But when growing large-fruited cranberries, one should not forget that they came to us from countries with a warmer climate, therefore, for the winter it must be covered with coniferous spruce branches, and covered with snow in winter.
Frosts are dangerous for cranberries during the growing season, since they can destroy a significant part of the buds and flowers.A young ovary is especially sensitive to them, which dies at a temperature of –1 ° С. Therefore, if there is a threat of frost, plantings must be protected by applying the usual methods to protect other berry crops - sprinkling, covering with foil or covering material.
Unfortunately, large-fruited cranberries are affected by hydroniasis, which causes softening, wateriness and yellowing of the berries. In this case, the plants are treated with a 1% solution of copper sulfate five weeks before the berries ripen.
Large-fruited cranberries are also remarkable as an ornamental crop. In the spring, during the growth of young shoots, its plantings appear light green; during flowering, they take on the appearance of a pale pink carpet. And in September, when its leaves and fruits acquire an orange-burgundy color, they acquire a spectacle of a unique beauty.
But, praising the large-fruited American cranberry, one should not forget that our marsh cranberry is distinguished by stable fruiting, excellent frost resistance, it has a shorter growing season, and its berries are stored better.
"Ural gardener", No. 46, 2010