A blueberry is a sweet, edible fruit produced by a blueberry bush (Vaccinium Cyanocccus). Blueberry bushes are grown worldwide, primarily in the United States, Europe, China.
Blueberries are native to North America where they are widely adapted, but need acidic soils and varying summer temperatures, so it is important to choose one that is right for your area.
Blueberries come in 4 different types: Northern Highbush, Northern Lowbush, Southern Highbush, and Rabbiteye.
Highbush blueberries are native to the temperate swamps, bogs, and low land areas of North America. They prefer rich, acid soils with regular water due to their shallow root systems. Highbush blueberries are the most commonly grown common type of blueberry with as easy to harvest upright habit and perfect size for row planting. With few exceptions Northern Highbush blueberries are the best selection for backyard growers and hobbyists.
Lowbush blueberries are native to the Northeastern United States and parts of Canada. Compared to standard Northern Highbush blueberries, the low bush varieties are considered to be "wild blueberries" and often harvested from managed, but otherwise naturally occurring berry patches. Low bush blueberries are small and short, but bear prolifically with smaller intensely flavored fruits. Great for hobbyists and growers with limited space.
Southern Highbush blueberries are a modern hybrid of the native Norther Highbush and Rabbiteye blueberries. These hybrids carry some of the best qualities of both, featuring the upright growth habit and larger flowers of the Norther Highbush, with the heat resistance and lower chill hours of the Rabbiteye types. Southern Highbush blueberries are sometimes evergreen in the right climate, such as the Pacific Northwest, and thrive in most temperate regions that would otherwise cause Northern Highbush blueberries to struggle. Southern Highbush blueberries are great for pot and containers as well due to their ability to enjoy a hotter and drier growing environment.
Rabbiteye blueberries are a related species of blueberry native to the Southeastern United Statesm as far north as North Carolina, as far south as Florida, and as far west as Texas. Unlike other kinds of blueberries Rabbiteye varieties are not self-fruitful and require pollination. Due to smaller, downward facing, flowers Rabbiteye blueberries also have fewer available pollinators making insects like the Southern Blueberry Bee very valuable in commercial cultivation. Rabbiteye blueberries are well suited for any grower in hotter climates where standard blueberries fail to thrive.
Blueberries come in a number of sizes to fit the needs of different growers. The shortest and smallest of blueberries belong to the Northern Lowbush varieties, while some varieties of Northern Highbush and Rabbiteye blueberries can reach sizes up to 6' tall and wide at maturity. No matter what growing circumstances you are in, from balcony pots to wide open spaces, there is a type of blueberry for you!
Blueberry bushes typically require some form of pollination. While many blueberries are partially self-fertile, some are not, and cross-pollination with a partner plant of a different variety will greatly increase the size, quantity, and quality of the blueberry harvest. Blueberries are insect pollinated plants typically serviced by bees. While most native pollinators will do the job, mason bees and honey bees are particularly good for pollinating blueberries and have the added benefit of being simple to manage for the average grower.
Pollination is important during your orchard planning as well, since you need pollinators to fly between your blueberry bushes. The pollinizers should be planted no further than 50 feet apart, and if possible be in line of sight, to ensure proper cross-pollination.
Blueberry bushes are hardy to USDA zones 4-9, unless otherwise noted, making it possible to grow them all over the United States! The USDA zone rating tells you the minimum winter temperature at which the plants typically survive when properly hardened off. On the USDA website you will find a USDA Hardiness Map which provides information on the average minimum winter temperature in your location, by zip code.
It should be understood that a USDA zone only refers to winter low temperatures and not the overall growing conditions for your area, such as rainfall, summertime temperatures, season length, soil quality, or any other factors that go into successfully growing your blueberries.
To regulate hormones and produce healthy flowers and fruits all plants must undergo a period of dormancy. Dormancy, which is like a kind of sleep for plants, is triggered by what we call "chill hours" or "chilling hours" - a period of time where the temperature is between 32 and 45 degrees Fahrenheit. Different varieties of plums will require different amounts of chill hours, with cultivars requiring less than 600 hours being considered "low-chill".
Both European and Asian plums have standard to high chill hour requirements at 700-1000+ for most varieties with a few exceptions.
If you have questions about the chill hours in your area contact your local Agriculture Extension Office to find out!
Blueberry bushes need to be planted where they receive at least 6-8 hours of direct sunlight as measured in early summer (late June to early August). Sufficient sun exposure triggers the initiation of new flower buds for the next growing season, without which there will be no fruit. Fruit ripening and flavor development are also benefited by the carbohydrate production stimulated by the sun, as well as it’s heat.
Blueberries tolerate a wide variety of soils, so long as they are regularly moist and moderately rich, with a pH around 4.5-5.5. Improve your soil where you intend to plant by mixing an inch or two of plant based organic matter, peat, or coconut coir into an area 2 times the diameter of the planting hole and up to a foot deep. A 2-4” deep layer of mulch (straw, leaves, or wood chips) applied after planting will continue to improve the soil and maintain mositure.
Allow sufficient space for both the top of the blueberry bush and it’s root system when selecting the planting location. Refer to size descriptions for each variety, keeping in mind these are generally managed or pruned sizes, not maximum potential sizes. If you are planting a berry patch be sure to include enough space between rows for transporting your supplies in and your fruit out.
Due to their size smaller blueberry varieties are easy and rewarding to grow in a pot! Tophat and Midnight Cascade are great examples of smaller plants that be grown in a standard sized pot or hanging basket.
As with any potted plant you will need to provide supplemental water more regularly than for a plant that is planted in the ground. Pots are hotter and drying environments than soil and so your plant will require more attention than it might otherwise. Additionally we suggest that you do not use soil from your garden in the pot, instead use a potting soil mix with some added compost to help with moisture retention and improve available nutrition.
This is the most important and often the most difficult part of successfully growing plants. There are many factors, including the humidity, temperature, soil type, wind, and amount of direct sun that affect how much and how often water should be applied.
A general rule of thumb for plants in the ground is to ensure they receive an inch of water per week over the root zone. An inch of water is equivalent to about ¾ to one gallon per square foot of soil surface area. The typical three foot diameter planting hole would need 7 ½ to 10 gallons of water per week provided by rainfall or by the gardener.
Apply this water once a week, two times per week if soil is fast draining. This will of course depend on your own conditions and the plants you are growing! DO NOT water lightly each day because this results in a wet surface and dry root zone area. The soil should be moist but not soggy to a depth of about a foot for most growing plants. The top inch or two can feel dry, and the plant still be well watered. The trick is to have the water available where the roots are. In hotter and sunnier areas, a mulch of straw, bark, etc. can greatly ease the burden of summer watering. For plants in containers, water until the soil is saturated and water comes out of the drainage holes. Let the container dry until the soil is dry to the touch 1-2 inches down and the container is lighter in weight. A plant that has wilted can be receiving either too much or too little water.
In rainy areas, like the Pacific Northwest, most of the plants that we offer will need relatively little supplemental irrigation ONCE THEY ARE WELL ESTABLISHED in the ground and have had a chance to develop a good root system. However even here it is important to make sure plants have regular, deep watering during the first couple of growing seasons, and the first summer is especially critical. In drier areas, permanent irrigation is essential. Remember that you don’t want your trees to just survive, but rather to thrive. Make sure they get the water they need.
One method is through drip irrigation. We use half- inch flexible plastic pipe with punch-in emitters for trees in the ground. For each young tree, we use two emitters, spaced one foot from the trunk. The pipe can be put on the ground, under the ground with risers, or tied loosely from the trees. We use emitters that drip one gallon per hour. There are many different styles of drip systems, some controlled by timers and others by hand. Or, each tree can be watered with a hose deeply about once a week. Sandy soils will need more frequent watering than clay soils. For smaller plants, like strawberries or raspberries, soaker hoses work very well.
For good steady growth and high productivity, your blueberries need to have adequate amounts of various mineral nutrients. Many people are fortunate and have naturally rich fertile soils with the acidic pH that blueberries need to thrive. Some soils are deficient in some nutrient or another and use of fertilizers, organic or chemical, can be highly beneficial if you want your bushes to grow well.
For blueberries you will want to use a blueberry or rhododendron fertilized, as they are specifically made for acid loving plants. A couple of inches of wood chip mulch is also recommended as it will not only conserve moisture and help in weed control, but also keeps your soil healthy by building up humus and maintaining an acidic pH for your blueberries to grow strong and healthy.
Use of concentrated products like chemical fertilizers or strong organics (for instance blood meal) is usually done from late winter through early summer. Applying fertilizer after early summer can encourage lots of soft new growth that is much more likely to be damaged by winter cold. Excessive use of fertilizer can in-crease disease problems on your plants and can even kill them. Use of too much fertilizer, whether chemical or organic, canals contribute to stream and groundwater pollution, so please try not to use more than your trees really need. As a general guide, if your tree is producing about one foot of new growth or more a year and has healthy looking foliage, it may not need much or any fertilizer.
Pests and disease are common hurdles for any grower. Ask your local co-operative extension professional what the typical insect and disease issues are in your area. Then you can make selections based on resistance or tolerance information available in our catalog, or, make a plan for controlling problems you can expect with the susceptible varieties you prefer to grow. If you see resistance information about a particular disease for one variety but not another of the same kind of fruit, then that variety may be susceptible or might not have been tested so is unknown. The following are some of the more common issues.
Newly formed pinkish leaves will often turn a rosy brown and sometimes form a shepherd’s crook or curl; infected berries become pinkish-purple and wrinkled, while healthy blueberries ripen and turn a dark bluish-purple. Infected berries at first appear swollen, then shrivel to about three-fourths of the normal fruit size and drop to the ground.
Cultural controls include destroying infected berries at harvest through burning or burial; also heavy mulching in winter to break reproductive cycle.
Because Monilinia vaccinii-corymbosi is wind and pollinator spread the most effective means of preventing the disease is breaking the life cycle at the overwintering stage.
Browsed shortened branches. Leaves are obviously munched on or plants are pulled up.
Fences or cages at least 8’ tall. Plastic mesh, electric, or woven wire fences.
At Raintree, an 8’ woven wire deer fence has worked best. Repellents don’t work consistently and, aside from fencing, only trained large dogs patrolling the perimeter are effective.
Fruits disappear or have gaping holes in them. Strawberries, blueberries, cherries and filberts are most susceptible but most fruits suffer occasionally.
Reflective Bird Scare Tape can work well. Bird netting. Cages.
Blue Jays start harvesting filberts when ready to pick, and so should you. Nuts dropped by jays are usually empty.
Bark eaten in a band from soil level up to 8” and roots eaten too, usually in snowy areas with lots of mulch or tall grass at base of trees.
Keep mulch 4”-6” away from trunk. Keep grass short and 1’-2’ from trunk. Use vinyl tree guard wrapped around trunk until tree well-established.
Voles and mice will chew a couple inches above ground and also into the root system. Rabbits will chew up to 8” high, particularly apple trees.
1/32 to 1/8” long pear shaped insects that multiply rapidly, especially on the underside of leaves and on stems. Can be pink, green, black or white. Leaves show red blisters or are curled-down and stems turn black with sooty mold.
Natural predators like lady bugs and parasitic wasps often provide control. Knock aphids off with water spray. Spray with Pyrethrin, Rotenone, Insecticidal Soap, or delayed dormant oil. Control ants if they are also present.
Trees can tolerate some infestation. Monitor in late spring and summer. Control is more important on new trees. Grow plants that attract predators, i.e. dill or yarrow.
Numerous ants scurrying up and down the tree trunk; aphids, scale or mealybug present in large numbers, lots of sticky honeydew, perhaps sooty mold.
Find hill and apply pesticide. Apply Tangle Trap over 2-3” wide band of paper wrapped around trunk. Eliminate other pathways into tree.
Ants nurture and protect these insects in exchange for their sugary secretions. Insects may be difficult to control until the ants are controlled.
Poking-type feeding damage followed by decay on fruits, nuts, berries and leaves. Deformity in the healthy tissue surrounding the dead tissue. Brown spots can show up in stored fruit.
Monitor with traps, some broad spectrum pesticides may work. Researchers are working on finding effective controls, but no info has been released yet.
BMSB over winters in groups in dry protected areas, such as houses. If you find them on or in your home use the vacuum, squishing releases their defensive stink. See stopbmsb.org for more info. Feeding begins in spring when the weather warms up and continues until new adults go dormant for winter.
Lesions on the upper surface of the leaf, or on the fruit or stems, followed by orange-ish structures on the bottom side of the leaf, or on the fruit or stems, which produce spores.
Copper fungicide after harvest before fall rains and again in early spring for prevention of some\ rusts. Remove and destroy infected parts of the plant. If possible select resistant varieties. Many varieties have not been studied. Cedar-apple rust is a problem east of the Rockies.
Rust diseases require an alternate host, removing the host (within 900’ radius), applying fungicides, or removing infected parts may help. Check with your extension office to see what rust diseases in fruiting plants may be common in your area, and their alternate host.
Vertical splits in bark appear spring or early summer, usually on the south or east side of the tree. Disease or insect infestations may then occur.
Whitewash trunk and lower limbs with interior latex paint cut 50/50 with water each fall until bark has thickened. Avoid planting in frost pockets or where water collects in winter.
Injury occurs during pattern of warm days followed by freezing nights. Sap gets stuck in trunk, freezes, then rapidly thaws in the warm sun the next day, rupturing cells.
