Cranberries are a group of evergreen dwarf shrubs or trailing vines in the sub-genus Oxycoccus of the genus Vaccinium. Cranberries are creeping shrubs or vines up to 2 metres (7 ft) long and 5 to 20 centimetres (2 to 8 in) in height. They have wiry stems and small evergreen leaves. The flowers are dark pink, with very distinct reflexed petals. The fruit is a berry that is larger than the leaves of the plant. It is initially light green, turning red when it is ripe. It has an acidic taste that can overwhelm its sweetness.
Most cranberries are processed into products such as juice, sauce, jam, and sweetened dried cranberries (see useful recipe for these below), with the remainder sold fresh to consumers. Cranberry Sauce (see recipe below) is a traditional accompaniment to turkey at Christmas dinner in the UK, and at Christmas and Thanksgiving dinners in the US.
The name cranberry derives from ‘craneberry’, first named by early European settlers in the US who believed the expanding flower, stem, calyx, and petals resembled the neck, head, and bill of a crane. Another name used in northeastern Canada is mossberry. The traditional English name for cranberries is fenberry, originated from plants found growing in fen (marsh) lands. In 17th-century New England cranberries were sometimes called ‘bearberries’ as bears were often seen feeding on them.
American Indians enjoyed cranberries cooked and sweetened with honey or maple syrup—a cranberry sauce recipe that was likely a treat at early New England Thanksgiving feasts. By the beginning of the 18th century, they were being exported to England by the colonists.
Cranberries were used by the Indians decoratively, as a source of red dye, and medicinally, as a poultice for wounds since not only do their astringent tannins contract tissues and help stop bleeding but we now also know that compounds in cranberries have antibiotic effects.
Although several species of cranberries grow wild in Europe and Asia, the cranberry most cultivated as a commercial crop is an American native, which owes its success to Henry Hall, an gentleman in Dennis, Massachusetts. In 1840 he noticed an abundance of large berries grew when sand was swept into his bog by the prevailing winds and tides. The sandy bog provided just the right growing conditions for the cranberries by stifling the growth of shallow-rooted weeds, enhancing that of the deep rooted cranberries. Cranberry cultivation spread across the US, but also across the sea to Scandinavia and the UK. Cranberries became popular for wild harvesting in the Nordic countries and Russia. In Scotland, the berries were originally wild-harvested but with the loss of suitable habitat the plants have become so scarce that this is no longer done. The berries arrived in Holland as survivors of a shipwreck: when an American ship loaded with crates filled with cranberries sank along the Dutch coast, many crates washed ashore on the small island of Terschelling. Some of the berries took root and cranberries have been cultivated there ever since.
Historically, cranberry beds were constructed in wetlands. Today’s cranberry beds are constructed in upland areas with a shallow water table. The topsoil is scraped off to form dykes around the bed perimeter. Clean sand is hauled in and spread to a depth of four to eight inches. The surface is laser levelled flat to provide even drainage. Beds are frequently drained with socked tile in addition to the perimeter ditch. In addition to making it possible to hold water, the dykes allow equipment to service the beds without driving on the vines. Irrigation equipment is installed in the bed to provide irrigation for vine growth and for spring and autumn frost protection.
To grow at home: if you can grow rhododendrons or blueberries in your garden soil, cranberries should succeed. Otherwise, grow plants in pots, hanging containers or raised beds in ericaceous compost. Water with rainwater, not ‘hard’ tap water. Compost should be moist at all times, not waterlogged and should never dry out. Peg down or bury long, trailing stems – these will root over time. Feed during the growing season, if growth is poor with a little hoof and horn (15g per sq m) or sulphate of ammonia. Old beds can be revitalised by covering them with a 14mm (½in) layer of sharp sand in spring and working the sand down between the stems.
Propagation: peg down trailing stems from March to June, to encourage rooting.
Little pruning is required, other than to remove any excessively long and congested arching growth in early spring. Trim out straggly roots after harvesting.
Cranberries need organic, rich, moist to boggy acidic soils, ideally at pH 4.5, in an open, sunny site. Although they like constantly moist conditions, plants should sit above the water. Plant in garden soil, providing it is suitable. Alternatively, dig a trench 90cm (36in) wide by 30cm (12in) deep and line it with heavy duty polythene or pond liner, fill it with ericaceous compost for acid loving plants and soak with rainwater before planting or create a raised bed, 30cm (12in) deep. Plant at a spacing of 30cm (12in) in and between the rows in from October to December, in mild spells in winter or in March and April.
As far as pests are concerned, cranberries are vulnerable to primarily birds. We netted ours as soon as berries appeared this year and fortunately managed to harvest the (few) all (our cranberry bushes were only just planted last season so to get a few berries was pretty wonderful). Harvest from late-September to mid-October, when the berries are red and prise easily from the plant. They can be frozen or eaten straight away. We froze our few this year to add to my dad’s wonderful yearly Christmas creation of Cranberry Sauce for our Christmas Day dinner (see recipe below).
RHS recommended varieties:
‘Pilgrim’: We have two of these. Ideal for container growing, fruits ripen from July to September.
‘Early Black’: Early harvesting, small and deep red; ideal for sauces and for baking.
‘Redstar’: Ideal for window boxes or containers, dark pink flowers are followed by bright red fruits.
‘Stevens’: Mid season with large, red fruit.
Raw cranberries have moderate levels of vitamin C, fibre and the essential manganese (each nutrient having more than 10% of the Daily Value per 100 g serving, as well as other essential micronutrients in minor amounts). As fresh cranberries are hard and bitter, about 95% of cranberries are processed and used to make cranberry juice and sauce. They are also sold dried and sweetened.
For many years, researchers believed that the ability of cranberries and cranberry juice to help prevent urinary tract infections (UTIs) was partly related to the strong acidity of the cranberries. Recent research has shown that it’s not the acidity of the cranberries, but the unusual nature of their proanthocyanidins (PACs) that is related to prevention of UTIs. The special structure of these PACs (involving A-type linkages between their components) acts as a barrier to bacteria that might otherwise latch on to the urinary tract lining. For the cardiovascular system and for many parts of the digestive tract (including the mouth and gums, stomach, and colon) cranberry has been shown to provide important anti-inflammatory benefits. It’s the phytonutrients in cranberry that are especially effective in lowering our risk of unwanted inflammation, and virtually all of the phytonutrient categories represented in cranberry are now known to play a role. These phytonutrient categories include proanthocyanidins (PACs), anthocyanins (the flavonoid pigments that give cranberries their shades of red), flavonols like quercetin, and phenolic acid (like hydroxycinnamic acids). Dietary consumption of cranberry has also been shown to reduce the risk of chronic, unwanted inflammation in the stomach, large intestine (colon) and cardiovascular system (especially blood vessel linings). Drinking a little cranberry juice now and then seems to be a good idea…
So if you don’t fancy your cranberries raw, try making your own cranberry juice (if you have enough to spare), perhaps a Cranberry Sauce instead of Redcurrant Jelly for your roasts (see recipe below) or dry them out like you would to make apple rings and use them in a bread recipe or follow my Christmas Brownie and Walnut Cake recipe and serve them alongside it for a delicious dessert (you don’t have to wait until Christmas for it!).
Dad’s Cranberry Sauce
(Makes 4x 350g jars)
-900g fresh/frozen cranberries -Juice of 2 oranges -150g granulated sugar
- Place the cranberries in a large pan.
- Add the juice of the oranges to the pan followed by the sugar.
- Bring everything up to simmering point, stir well, put a lid on the pan and let it all simmer for about 20 minutes, or until the cranberries are breaking down. Stir now and then.
- Remove the pan from the heat. When it is cool enough to handle, scrape into sterilised jam jars. Store in the fridge. For freezing, when cool transfer the relish to a plastic container and freeze.
-200g plain chocolate- 100g salted butter -4 medium sized eggs -250g caster/granulated sugar -100g plain flour -1tsp baking powder -30g cocoa powder -100g walnuts, ground
- Preheat the oven to 180C. Line a 23cm/9inch cake tin with baking parchment.
- Melt the chocolate in a heatproof bowl in the microwave. Melt the butter and add to the chocolate mixture.
- Whisk the eggs and sugar together until the mixture is pale and thick enough to hold a trail when the beaters are removed. Mix in the chocolate and butter mixture.
- Add the flour, baking powder and cocoa powder, mixing to combine.
- In a food processor or nut grinder, grind the walnuts. Mix into the other ingredients thoroughly.
- Pour the mixture into the prepared cake tin. Bake in the oven for 40-45 minutes until the cake has a nice crust on the outside but is slightly soft in the middle. When you cut into it to serve, it should gradually get gooey-er as you go further into the middle, the brownie element of the cake. Leave to cool in the tin.
- Dust with icing sugar and scatter dried cranberries in the middle for decoration. Serve these cranberries alongside the slices. Store in an airtight container.