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List of fruit to grow

Blueberries

Blueberries

Blueberries, Vaccinium corymbosum, taste delicious whether eaten fresh or cooked. They can be evergreen or deciduous and usually grow to about 1.5m (5ft) high. Pretty, white flowers appear in spring; attractive, blue berries arrive in summer and in autumn the foliage erupts into a spectacular blaze of colour.

Planting blueberries

Blueberries require light, free-draining acidic soils, with plenty of rich, organic matter if they are to thrive. The soil should have a pH of between 4 and 5.5, similar to the requirements of rhododendrons and camellias. It is possible to lower the pH levels of your soil with sulphur chips or dust. However, they will need to be added three weeks before planting to take effect. Monitor the soil's pH every few years, because it may be necessary to add acid. If you do not have suitable soil, simply grow blueberries in a pot containing acidic soil, such as ericaceous compost, giving the plants a high potash feed (such as tomato feed) occasionally during the growing season.

Growing tips

Plant two different varieties of blueberries to ensure cross-pollination. A single blueberry plant will produce fruit, but the yields will be higher and the fruits bigger if more than one plant is grown. Blueberries require a position in full sun or light shade. Plant blueberries in the dormant season leaving about 1.5m (5ft) gaps between them. Mulch with a layer of acidic peat, wood chippings or pine needles. Water the plants in well. Use rainwater because tap water contains lime.

Maintenance

Use nets to protect plants from birds in the fruiting season. Mulch each spring. Chipped up pine tree or pine needles are ideal mulches to place around plants because they are fairly acidic. Water plants regularly. They require water from when their buds begin to show in spring until their leaves fall in autumn. Again, remember to use rainwater.

Pruning blueberries

Blueberries produce fruit on branches that were produced the previous year. For the first two or three years of a blueberry's life it is not necessary to prune it much, apart from keeping the plant tidy. After this, blueberries need regular pruning to maintain plant vigour and high quality berry production. Prune them between November and March when the plant is dormant. Prune out dead, dying and diseased wood. Locate the oldest canes and remove one or two at the base each year. Remove the old canes that do not produce much fruit to make way for younger more productive canes. Prune out low branches that will lie on the ground when laden with fruit. Remove all twiggy wood on the ends of fruiting laterals.

Aftercare

Harvesting and storing blueberries Harvesting can be tricky because the fruits, which are borne in clusters, ripen at different times. This could mean having to regularly pick the same bush over the ripening period.

Fruits are ready to pick when they have turned a deep blue. The fruit should easily pull away from the cluster when ripe.

However, leave them on the bush for a few more days after they turn blue for a more intense and complex flavour. They must be picked or they will drop.

If the blueberries are not being eaten immediately, keep them in a fridge in a shallow tray. They also freeze well and make delicious jam. Alternatively, make those classic American favourites, blueberry muffins.

For more recipe suggestions visit bbc.co.uk/food

Pests

Except for birds, there are no significant pests and diseases in the UK.

Blueberry varieties

'Earliblue'

This is a vigorous, early ripening variety. It has medium to large, light blue berries, excellent sweet flavour and impressive autumn colour.

'Bluetta'

'Bluetta' is a fairly tasty and vigorous, compact variety, with a spreading habit, producing a medium-sized, light blue berry.

'Patriot'

This blueberry is a high-yielding, vigorous, hardy variety with medium to large blue berries and excellent flavour.

'Bluecrop'

This variety has large, light blue berries with good flavour. It is slightly aromatic and has excellent orange and copper leaves in autumn.

'Herbert'

Many people say that 'Herbert' is the tastiest variety of blueberry. It produces large berries and has moderate vigour.

'Bluejay'

This is a mid-season, fast-growing, reliable variety that has superb autumn colour. It only produces moderate yields of medium large berries, but has a good, slightly tart flavour.

'Ivanhoe'

'Ivanhoe' is a mid-season, erect variety with large, delicious, dark blue berries. It is a vigorous plant with good autumn colour.

'Bluegold'

'Bluegold', which is a mid- to late season variety, is vigorous, but low-growing, with high yields. It is ideal for growing in pots and produces very tasty berries in August. The fruit has a longer life than most varieties.

'Coville'

The fruit on this very late, vigorous variety is large and can be left on the bush for a long time before dropping.

With flavors that range from mildly sweet to tart and tangy, blueberries are nutritional stars bursting with nutrition and flavor while being very low in calories. Blueberries are at their best from May through October when they are in season.

Blueberries are the fruits of a shrub that belong to the heath family, which includes the cranberry and bilberry as well as the azalea, mountain laurel and rhododendron. Blueberries grow in clusters and range in size from that of a small pea to a marble. They are deep in color, ranging from blue to maroon to purple-black, and feature a white-gray waxy "bloom" that covers the surface serving as a protective coat. The skin surrounds a semi-transparent flesh that encases tiny seeds.

Health Benefits

Blueberries are literally bursting with nutrients and flavor, yet very low in calories. Recently, researchers at Tufts University analyzed 60 fruits and vegetables for their antioxidant capability. Blueberries came out on top, rating highest in their capacity to destroy free radicals.

An Antioxidant Powerhouse

Packed with antioxidant phytonutrients called anthocyanidins, blueberries neutralize free radical damage to the collagen matrix of cells and tissues that can lead to cataracts, glaucoma, varicose veins, hemorrhoids, peptic ulcers, heart disease and cancer. Anthocyanins, the blue-red pigments found in blueberries, improve the integrity of support structures in the veins and entire vascular system. Anthocyanins have been shown to enhance the effects of vitamin C, improve capillary integrity, and stabilize the collagen matrix (the ground substance of all body tissues). They work their protective magic by preventing free-radical damage, inhibiting enzymes from cleaving the collagen matrix, and directly cross-linking with collagen fibers to form a more stable collagen matrix.

Cardioprotective Action

While wine, particularly red wine, is touted as cardioprotective since it is a good source of antioxidant anthocyanins, a recent study found that blueberries deliver 38% more of these free radical fighters. In this study, published in the August 2003 issue of the Journal of Agriculture and Food Chemistry, researchers found that a moderate drink (about 4 ounces) of white wine contained .47 mmol of free radical absorbing antioxidants, red wine provided 2.04 mmol, and a wine made from highbush blueberries delivered 2.42 mmol of these protective plant compounds.(October 1, 2003)

Cholesterol-lowering Pterostilbene

Pterostilbene (pronounced TARE-oh-STILL-bean), a powerful antioxidant compound found in blueberries, which is already known to fight cancer, may also help lower cholesterol.

In a study using rat liver cells, scientists at the USDA Agricultural Research Service compared the cholesterol-lowering effects of pterostilbene to those of ciprofibrate, a lipid-lowering drug, and resveratrol, an antioxidant found in grapes with a chemical structure similar to pterostilbene that has been shown to help fight cancer and heart disease.

They based their comparison on each compound's ability to activate PPAR-alpha (short for peroxisome proliferator-activated receptor alpha). The PPARs are a family of receptors on cells all throughout the body that are involved in the absorption of compounds into cells for use in energy production. PPAR-alpha is crucial for the metabolism of lipids, including cholesterol. Pterostilbene was as effective as ciprofibrate and outperformed resveratrol in activating PPAR-alpha. The take away message: turn up your cholesterol burning machinery by eating more blueberries, grapes and and cranberries. (January 14, 2005)

A Visionary Fruit

Extracts of bilberry (a variety of blueberry) have been shown in numerous studies to improve nighttime visual acuity and promote quicker adjustment to darkness and faster restoration of visual acuity after exposure to glare. This research was conducted to evaluate claims of bilberry's beneficial effects on night vision made by British Air Force pilots during World War II who regularly consumed bilberry preserves before their night missions.

Protection against Macular Degeneration

Your mother may have told you carrots would keep your eyes bright as a child, but as an adult, it looks like fruit is even more important for keeping your sight. Data reported in a study published in the June 2004 issue of the Archives of Opthamology indicates that eating 3 or more servings of fruit per day may lower your risk of age-related macular degeneration (ARMD), the primary cause of vision loss in older adults, by 36%, compared to persons who consume less than 1.5 servings of fruit daily.

In this study, which involved 77,562 women and 40,866 men, researchers evaluated the effect of study participants' consumption of fruits; vegetables; the antioxidant vitamins A, C, and E; and carotenoids on the development of early ARMD or neovascular ARM, a more severe form of the illness associated with vision loss. Food intake information was collected periodically for up to 18 years for women and 12 years for men.

While, surprisingly, intakes of vegetables, antioxidant vitamins and carotenoids were not strongly related to incidence of either form of ARM, fruit intake was definitely protective against the severe form of this vision-destroying disease. Three servings of fruit may sound like a lot to eat each day, but by simply tossing a banana into your morning smoothie or slicing it over your cereal, topping off a cup of yogurt or green salad with a half cup of blueberries, and snacking on an apple, plum, nectarine or pear, you've reached this goal. (June 30, 2004)

A Better Brain with Blueberries

In animal studies, researchers have found that blueberries help protect the brain from oxidative stress and may reduce the effects of age-related conditions such as Alzheimer’s disease or dementia. Researchers found that diets rich in blueberries significantly improved both the learning capacity and motor skills of aging rats, making them mentally equivalent to much younger rats.

Blueberries cross the blood brain barrier to improve learning and memory Spanish researchers at the University of Barcelona found that after 8 weeks of feeding lab rats various blueberries, they saw a reversal of age-related declines in the rats' ability to find their way through the Morris water maze, a measure of the animals spatial learning ability and memory.

They thought these mental improvements were due to blueberry phytonutrients, but they weren't sure if the phytonutrients derived from eating blueberries were able to act directly on brain cells, so they designed a study, published in the April 2005 issue of Nutrition and Neuroscience to see whether blueberry polyphenols could be found in brain areas associated with cognitive performance.

They gave old rats (aged 19 months) either a control or 2% blueberry diet for 8-10 weeks, tested them in the Morris water maze to check their spatial learning and memory, and then analyzed different brain regions for the presence of anthocyanins.

In the rats given the blueberry-containing diet, several anthocyanins were found in the cerebellum, cortex, hippocampus or striatum, but not in the controls— findings that are the first to show that blueberry's polyphenols can cross the blood brain barrier and localize in various brain regions important for learning and memory. Further analyses showed that the more blueberry anthocyanin compounds found in a rat's cortex, the better the rat did in the Morris water maze test, suggesting that the beneficial actions of blueberry's polyphenols work directly on brain tissue.

Protect the Brain from Damage After a Stroke

Eating plenty of blueberries may significantly lessen brain damage from strokes and other neurological disorders, suggests a study published in the May 2005 issue of the Journal of Experimental Neurology.

Neuroscientists at the University of South Florida College of Medicine, James A. Haley Veterans' Hospital and the National Institute on Drug Abuse found that rats fed diets enriched with blueberries, spinach or spirulina (a type of algae) suffered the loss of much fewer brain cells and recovered significantly more of their ability to move following a stroke.

The researchers studied four groups of rats. All were fed equal amounts of food for one month. The control (untreated) group ate chow only. A second group was given rat chow supplemented with blueberries, the third got chow with spinach, and the fourth received chow with spirulina.

After four weeks, an ischemic stroke with reperfusion was induced in the rats. (An ischemic stroke occurs when a blood clot blocks an artery, cutting off the supply of oxygen to the brain with the result that brain cells can be severely damaged and die). When the clot is cleared, the pent up oxygenated blood quickly rushes back in. Known as reperfusion, this restoration of blood flow can also result in brain damage as it causes cellular swelling, edema and the production of free radicals.

Rats given blueberry or spinach along with their chow, however, were protected: the size of the area of their brains damaged by the stroke was half that seen in the brains of the control rats.

Rats fed spirulina-enriched diets did even better; their stroke lesions were 75 per cent smaller than those of controls. In addition, but not surprisingly, rats pretreated with the blueberry, spinach or spirulina diets also showed regained more of their abilities to move after the stroke than rats in the control group. Neuroscientists think the reason for the improved outcome in blueberry, spinach or algae-treated rats is the same as that demonstrated in previous University of Florida/Veterans Administration research, which revealed that diets enriched with blueberries, spinach or spirulina reversed normal age-related declines in memory and learning in old rats. All these foods are exceptionally rich in antioxidants, which neuroscientists believe able to largely counteract the burst of free radicals triggered in brain cells by an ischemic stroke. It is this sudden excessive production of free radicals that damages the lipids, proteins and DNA in brain cells, causing their death.

Several ingredients in blueberries, including their flavonoids and anthocyanins, have been shown to have strong antioxidant activity. Similar to blueberry, spinach leaves also contain high levels of antioxidants flavonoids, p-coumaric acid, 9-cis-β-carotene, and other water-soluble natural antioxidants. Just how powerful these compounds are is suggested by the fact that blueberries and spinach were each given as only 2% of the two supplemented rat diets.

Protection Against Colon Cancer

In addition to their powerful anthocyanins, blueberries contain another antioxidant compound called ellagic acid, which blocks metabolic pathways that can lead to cancer. In a study of 1,271 elderly people in New Jersey, those who ate the most strawberries (another berry that contains ellagic acid) were three times less likely to develop cancer than those who ate few or no strawberries. In addition to containing ellagic acid, blueberries are high in the soluble fiber pectin, which has been shown to lower cholesterol and to prevent bile acid from being transformed into a potentially cancer-causing form.

Laboratory studies published in the September 2005 issue of the Journal of Agricultural and Food Chemistry show that phenolic compounds in blueberries can inhibit colon cancer cell proliferation and induce apoptosis (programmed cell death).

Extracts were made of the blueberry phenols, which were freeze-dried and further separated into phenolic acids, tannins, flavonols, and anthocyanins. Then the dried extracts and fractions were added to cell cultures containing two colon cancer cell lines, HT-29 and Caco-2.

In concentrations normally found in rat plasma after eating blueberries, anthyocyanin fractions increased DNA fragmentation (a sign that apoptosis or cell death had been triggered) by 2-7 times. Flavonol and tannin fractions cut cell proliferation in half at concentrations of 70-100 and 50-100 microg/mL, while the phenolic fraction was also effective, but less potent, reducing proliferation by half at concentrations of 1000 microg/mL. Bottomline: eating blueberries may reduce colon cancer risk.

Healthier Elimination

Blueberries can help relieve both diarrhea and constipation. In addition to soluble and insoluble fiber, blueberries also contain tannins, which act as astringents in the digestive system to reduce inflammation. Blueberries also promote urinary tract health. Blueberries contain the same compounds found in cranberries that help prevent or eliminate urinary tract infections. In order for bacteria to infect, they must first adhere to the mucosal lining of the urethra and bladder. Components found in cranberry and blueberry juice reduce the ability of E. coli, the bacteria that is the most common cause of urinary tract infections, to adhere.

Description

Blueberries are the fruits of a shrub that belong to the heath (Ericaceae) family whose other members include the cranberry and bilberry as well as the azalea, mountain laurel and rhododendron. Blueberries grow in clusters and range in size from that of a small pea to a marble. They are deep in color, ranging from blue to maroon to purple-black, and feature a white-gray waxy “bloom” that covers the berry's surface serving as a protective coat. The skin surrounds a semi-transparent flesh that encases tiny seeds. Cultivated blueberries are typically mildly sweet, while those that grow wild have a more tart and tangy flavor.

History

Blueberries are native to North America where they grow throughout the woods and mountainous regions in the United States and Canada. This fruit is rarely found growing in Europe and has only been recently introduced in Australia.

There are approximately 30 different species of blueberries with different ones growing throughout various regions. For example, the Highbush variety can be found throughout the Eastern seaboard from Maine to Florida, the Lowbush variety throughout the Northeast and Eastern Canada, and the Evergreen variety throughout states in the Pacific Northwest.

While blueberries played an important role North American Indian food culture, being an ingredient in pemmican, a traditional dish composed of the fruit and dried meat, they were not consumed in great amounts by the colonists until the mid-19th century. This seems to be related to the fact that people did not appreciate their tart flavor, and only when sugar became more widely available as a sweetener at this time, did they become more popular.

Blueberries were not cultivated until the beginning of the 20th century, becoming commercially available in 1916. Cultivation of blueberries was spearheaded by a botanist at the United States Department of Agriculture who pioneered research into blueberry production. His work was forwarded by Elizabeth White, whose family established the first commercial blueberry fields.

How to Select and Store

Choose blueberries that are firm and have a lively, uniform hue colored with a whitish bloom. Shake the container, noticing whether berries have the tendency to move freely; if they do not, this may indicate that they are soft and damaged or moldy. Avoid berries that appear dull in color or are soft and watery in texture. They should be free from moisture since the presence of water will cause the berries to decay. When purchasing frozen berries, shake the bag gently to ensure that the berries move freely and are not clumped together, which may suggest that they have been thawed and refrozen. Blueberries that are cultivated in the United States are available from May through October while imported berries may be found at other times of the year.

Ripe blueberries should be stored in a covered container in the refrigerator where they will keep for about a week, although they will be freshest if consumed within a few days. Always check berries before storing and remove any damaged berries to prevent the spread of mold. But don't wash berries until right before eating as washing will remove the bloom that protects the fruit’s skin from degradation. If kept out at room temperature for more than a day, the berries may spoil.

Ripe berries can also be frozen, although this will slightly change their texture and flavor. Before freezing, wash, drain and remove any damaged berries. To better ensure uniform texture upon thawing, spread the berries out on a cookie sheet or baking pan, place in the freezer until frozen, then put the berries in a plastic bag for storage in the freezer. Berries should last up to a year in the freezer.

Tips for preparing blueberries:

Fresh berries are very fragile and should be washed briefly and carefully and then gently patted dry if they are not organic. Wash berries just prior to use, to not prematurely remove the protective bloom that resides on the skin’s surface. If you know the source of either wild or organic berries try not to wash them at all.

When using frozen berries in recipes that do not require cooking, thaw well and drain prior to using. For cooked recipes, use unthawed berries since this will ensure maximum flavor. Extend the cooking time a few minutes to accommodate for the frozen berries. You may notice that berries used in baked products may take on a green color. This is a natural reaction of their anthocyanidin pigments and does not make the food item unsafe to eat.

A few quick serving ideas:

Add frozen blueberries to your breakfast shake. If the blender container is plastic, allow berries a few minutes to soften, so they will not damage the blender.

Fresh or dried blueberries add a colorful punch to cold breakfast cereals.

For a deliciously elegant dessert, layer yogurt and blueberries in wine glasses and top with crystallized ginger.

Blueberry pie, cobbler and muffins are classic favorites that can be enjoyed throughout the year.

Safety

Blueberries and Oxalates Blueberries are among a small number of foods that contain any measurable amount of oxalates, naturally-occurring substances found in plants, animals, and human beings. When oxalates become too concentrated in body fluids, they can crystallize and cause health problems. For this reason, individuals with already existing and untreated kidney or gallbladder problems may want to avoid eating large amounts of blueberries. Oxalates may also interfere with absorption of calcium from the body. For this reason, individuals trying to increase their calcium stores may want to avoid eating blueberries with calcium-rich foods, or if taking calcium supplements, may want to eat them 2-3 hours before or after taking their supplements.

Blueberries, Fresh 1.00 cup 81.20 calories Nutrient Amount DV (%) Nutrient Density World's Healthiest Foods Rating vitamin C 18.86 mg 31.4 7.0 very good manganese 0.40 mg 20.0 4.4 very good dietary fiber 3.92 g 15.7 3.5 very good vitamin E 1.46 mg 7.3 1.6 good World's Healthiest Foods Rating Rule excellent DV>=75% OR Density>=7.6 AND DV>=10% very good DV>=50% OR Density>=3.4 AND DV>=5% good DV>=25% OR Density>=1.5 AND DV>=2.5%