Blueberry Cultivars for Georgia
Gerard Krewer << gkrewer@uga.edu >> Extension and Research Horticulturist and D. Scott NeSmith << snesmit@gaes.griffin.peachnet.edu >> Research and Extension Horticulturist
University of Georgia Fruit Publication 00-2
Types or Species of Blueberries Grown in Georgia
Three types of blueberries are grown in Georgia: rabbiteye, southern highbush, and northern highbush. Rabbiteyes are adapted statewide, but low chilling rabbiteyes should not be planted in the mountains because they bloom too early. Southern highbush are best adapted to south Georgia, except for a few new higher-chilling cultivars such as 'Ozark Blue' and 'Reveille'. Northern highbush are best adapted to the mountain highlands.
The rabbiteye blueberry is native to south Georgia, north Florida, and southeast Alabama. A breeding program begun in Tifton in the 1940's by Dr. Tom Brightwell, in cooperation with the USDA, has produced several high quality rabbiteye blueberry cultivars. Cultivars from the Georgia-USDA breeding program form the backbone of the Georgia blueberry industry. Some cultivars from the North Carolina-USDA breeding program have also performed well in Georgia. These cultivars ripen from early June through late July in south Georgia. Ripening in north Georgia is about one month later. In general, the rabbiteye blueberry is the most productive and leaf/stem disease-tolerant blueberry grown in Georgia. They grow well on many types of acidic, low organic matter soils from sands to loams to sandy clay loams. Southern highbush and northern highbush need a soil that is high in organic matter and are much less forgiving plants in general than rabbiteyes. Some disadvantages of rabbiteye blueberries are: 1) some cultivars bloom relatively early in the spring so spring freeze damage can be a problem; 2) most cultivars are self-unfruitful so they are more susceptible to pollination problems than the partial self-fertile southern or northern highbush; 3) most cultivars ripen later than southern highbush in south Georgia or northern highbush in north Georgia.
Rabbiteye blueberry plantings are relatively expensive to establish, but once established, plantings generally remain productive for a long period of time. Some commercial plantings established in Georgia in 1958 are still producing. Well-managed, mature fields typically yield five to eight thousand pounds of harvested berries per acre and can be higher in some years. Blueberry orchards which are poorly managed may yield only two to three thousand pounds of fruit per acre.
Southern highbush blueberries are crosses between the highbush blueberry (northern type) and native southern blueberries such as Darrow's evergreen blueberry. Some southern highbush blueberries are very early ripening and have commercial potential for the April and May market window in south Georgia. Southern highbush cultivars with a low winter chilling requirement bloom very early, so they are best adapted to south Georgia. They are generally more difficult to grow than rabbiteyes, but their fruit ripens very early and brings a good price. They have specific site requirements covered later in the bulletin. Since they have only been grown commercially for a few years in Georgia, it is not known how long plantings will remain profitable before they decline from pest problems and depletion of soil organic matter. An orchard life of 10-20 years may be a realistic goal. In North Carolina, old highbush sites are often planted with rabbiteye blueberries.
The northern highbush blueberry is native to the eastern coast of the United States and is the type grown commercially in New Jersey and Michigan. The highbush blueberry has potential as a source of later blooming, but early ripening fruit for the Georgia mountains. However, since they have not been extensively planted in Georgia information is limited at this time. Plantings of highbush blueberries should be considered on a trial basis. They have specific site requirements covered later in the bulletin. They are poorly adapted to the hotter parts of the state due to insufficient winter chilling and heat stress.
Getting Started in the Blueberry Business
The two most important rules in starting blueberry production are: 1) Site selection, and 2) Cultivar selection. Good cultivar selection will determine to a large extent the potential profitability of your blueberry operation. If you are a new grower in the Coastal Plain or Piedmont, start with rabbiteyes and experiment with southern highbush if you have suitable soil or are willing to extensively amend the soil. Pay close attention to the chilling requirement of cultivars, and do not plant low chilling ones in the Piedmont, since they will bloom too early. If you are a new grower in the Mountains, start with the higher chilling rabbiteyes and experiment with northern highbush and the higher chilling southern highbush cultivars.
Chilling Requirement Plus Heat Units After Chilling Determines the Bloom Date
In Georgia, relative bloom dates of various blueberry cultivars are related largely to the chilling requirement of the flower buds. Chilling requirement is defined (in peaches) as the number of hours (chill hours) of winter temperatures 45 degrees F and below that plants must be exposed to for 90% of the buds or blooms to open and develop "normally" following a two week period of exposure to "warm" weather. For blueberries, the heat unit requirement (period of exposure to warm temperatures) after chilling is much higher than in peach, and may vary depending on cultivar. Therefore, slight variations in bloom dates occur from year to year more often in blueberries than in peaches.
If a blueberry cultivar fails to receive adequate chilling, bloom and leaf development will be very late and erratic. This results in a reduced crop of later-than-normal ripening fruit. For instance, 'Reveille' performed very poorly in south Georgia following the winter of 1998-99. 'Reveille' is thought to require 600-800 chill hours and only about 450 chill hours were received, and as a result, the crop was light and missed the market window. A few exceptional blueberry cultivars can set fruit with less winter chilling than their reported chilling requirement. An example is 'Powderblue', which has a supposed chilling requirement of 650 hours, but sets good crops of fruit as far south as Gainesville, Fla. (a 400 chill hour zone).
Chilling requirement information can be used to project relative bloom dates. As a general rule in south Georgia, 200-300 hour cultivars will bloom heavily in mid to late February, 400-500 hour cultivars in early to mid March, and 600-800 hour cultivars in mid to late March. Cultivars with a chilling requirement of 400 hours or less may need overhead irrigation for frost protection for reliable cropping in south Georgia. It is not recommended that cultivars with a chilling requirement of 400 hours or less be planted in middle or north Georgia.
RABBITEYE BLUEBERRIES
General Information on Rabbiteye Blueberries
Select rabbiteye cultivars based on your intended method of harvest, sale and location. Certain cultivars are not adaptable to machine-harvest, fresh market sales; however, these same cultivars may be excellent choices for pick-your-own operations. Rabbiteye blueberries are mostly self-unfruitful and require cross pollination for acceptable fruit set.
Spring frost and freezes can be a major problem in rabbiteye blueberry production. Do not plant cultivars with very low chilling requirements in areas of the state or in fields likely to have spring freeze problems. These areas include frost pockets in low areas of south Georgia, and most of middle Georgia and north Georgia. In these areas only plant the highest chilling, latest blooming rabbiteyes. Do not plant rabbiteyes with a chilling requirement of less than 400 hours anywhere in north Georgia.
Rabbiteye Cultivars
Rabbiteye cultivars are listed in approximate ripening order. Ripening dates in middle Georgia will be about ten days to two weeks later than south Georgia. Ripening dates in north Georgia will be about three to four weeks later than south Georgia. Because most rabbiteye blueberries require cross-pollination for maximum fruit set, plant a minimum of two cultivars with a similar chilling requirement in each field. The most promising cultivars for the commercial blueberry belt in south Georgia are marked with an asterisk (*).
(Pat.) Windy has a chilling requirement of about 300 hours and blooms with Aliceblue and Beckyblue. Approximate ripening date in south Georgia is mid May to early June. Fruit of Windy appear to be sufficiently firm and have a good enough scar to allow mechanical harvest for the fresh market shipping with good weather conditions. However, this has not been adequately tested. The fruit has good firmness and flavor. Bushes are moderately vigorous and upright. Windy may have root rot problems so do not plant it on sites with poor drainage. This cultivar is highly susceptible to the blueberry gall midge and is currently not recommended in Florida until more is learned about controlling the gall midge. Suggested only for limited trial in south Georgia. Overhead irrigation for freeze protection may be needed for consistent cropping. Suggested pollinizers are Aliceblue and Beckyblue. Released by Florida in 1991.
(Pat.) Snowflake has a chilling requirement of about 400-500 hours and blooms with Climax and Woodard. Approximate ripening date in south Georgia is mid to late May. The fruit must be hand picked for the fresh market and is too soft for easy distant shipping. The picking scar on Snowflake is satisfactory, but not excellent. The flavor is good to excellent, the fruit are medium in size and have good color. Bushes have a spreading growth habit and produce more sprouts from the base than most rabbiteye cultivars. These sprouts continually renew the bush, but more pruning than normal will be necessary if a narrow plant row is desired. Snowflake plants have shown poor resistance in the field to Phytophthora root rot, but have good resistance to stem blight. Good soil drainage and the use of root rot control chemicals may be necessary to grow Snowflake successfully. It has not been planted in Georgia because the fruit are so soft. Suggested pollinizers are Brightwell, Climax, and Bluebelle. Released by Florida in 1991.
Beckyblue has a chilling requirement of 300-400 hours. This cultivar blooms early most years, and as a result frequently suffers freeze damage if grown without frost protection. Approximate ripening date in south Georgia is late May to early June. The fruit have good color, size, firmness and a dry picking scar. Beckyblue can be mechanically harvested for the fresh market during good weather conditions. The bush is moderately vigorous. Suggested pollinizers are Windy and Climax. Released by Florida in 1978.
Aliceblue has a chilling requirement is 300-400 chill hours. This cultivar blooms early most years, resulting in frequent freeze damage. Approximate ripening date in south Georgia is late May to early June. Bushes are vigorous and upright. Fruit are fairly firm, have good color and size, and have a fairly dry picking scar. Aliceblue is no longer recommended in Florida because of fruit set problems due to diseases and cross-incompatibility with Beckyblue. Information from Georgia is very limited. Suggested pollinizers are Climax and Windy. Released by Florida in 1978.
*Premier has a chilling requirement of about 550 hours. Approximate ripening date in south Georgia is very late May to mid June. The fruit are large with good color, stem scar, and flavor. This cultivar can be harvested mechanically for the fresh market in some years, especially if harvested on a frequent basis. It is recommended for planting for the fresh market on farms that can be picked by hand or very regularly with mechanical harvesters. If the fruit is not picked frequently it may be too soft for the fresh market. The bushes are upright in growth habit and vigorous. Premier is reported to grow better than many other cultivars on sites with marginally high soil pH in North Carolina. Canes on young plants can be too limber to support the fruit load, and may require some pruning. Suggested pollinizers are Climax and Austin. Released by North Carolina in 1978.
Montgomery has a chilling requirement of about 550 hours and blooms with Premier. Cropping in N.C. has been better than Premier. Approximate season of ripening in south Georgia is very late May to mid June, over lapping with and slightly later than Premier. Fruit size is medium-large. The fruit have good color, picking scar, and flavor. Fruit firmness is average. Montgomery is probably mechanically harvestable for the fresh market if picked on a frequent basis during good weather conditions. The bushes are moderately vigorous and semi-upright in habit. Recommended for very limited trial. Suggested pollinizers are Austin and Premier. Release by North Carolina in 1997.
* Austin has a chilling requirement of about 450-500 hours. Peak time of flowering is about 5-7 days after Climax. Approximate time of ripening in south Georgia is early to mid June. The fruit ripen with Climax in most years and start just after Climax in other years. The fruit are medium-large in size with good color, stem scar, and flavor. Austin is moderately vigorous, productive, has an upright growth habit and adequate renewal cane production. The fruit are slightly softer than Climax, but should be mechanically harvestable for the fresh market with good weather conditions. Suggested pollinizers are Climax, Premier, and Brightwell. Released from Georgia in 1996.
* Climax has a chilling requirement of about 400-450 hours, blooms very early most years, and frequently suffers freeze damage. Cropping history following the freezes of 1993, 1996, and 1998 was poor, so this cultivar has been declining in favor with many growers. Approximate time of ripening in south Georgia is early to mid June, and lasting about 20 days. About 80% of Climax's crop can be harvested in the first two pickings. Berries are medium in size with good color, small scar and good flavor. Fruit firmness is excellent, making this cultivar very suitable for mechanical harvesting for the fresh market. Plants habit is upright and open. Climax does not produce many canes from ground level, so be careful not to remove too many canes during cane renewal pruning. Suggested pollinizers are Austin and Premier. Released by Georgia in 1974.
Bonita has a chilling requirement of 350-400 chill hours, blooms very early most years, and frequently suffers freeze damage. Approximate time of ripening in south Georgia is early to late June. The fruit are large in size, with good firmness, color and a dry picking scar. The fruit can be mechanically harvested for the fresh market with good weather conditions. Bush habit is medium in spread and fairly vigorous. Bonita appears to be too susceptible to root rot for general planting. It should be tested only on sites with excellent drainage. A suggested pollinizer is Climax. Released by Florida in 1985.
Bluegem has a chilling requirement of 350-400 hours, blooms early most years, and frequently suffers freeze damage. Approximate date of ripening in south Georgia is mid June to early July. Harvest starts just after Climax most years. The berries are medium in size, are very firm, have a small, dry picking scar and have good color. Bluegem can be mechanically harvested for the fresh market with good weather conditions. Bush habit is moderately spreading and moderately vigorous. Bluegem is very sensitive to wet soils and must be grown only a sites with excellent drainage. No longer recommended for planting in Georgia. Released by Florida in 1970.
Ira has a chilling requirement of about 700-800 hours and blooms about two days after Tifblue in North Carolina. It fruits very well in the Piedmont of North Carolina (even during1996 and 1998 when many rabbiteye cultivars failed due to freeze damage). Approximate date of ripening in south Georgia is probably mid June to late July. The berries are medium in size with average or better firmness, picking scar, and color. Ira can probably be mechanically harvested for the fresh market with good weather conditions. Stems are usually not a problem, but in one year when the bushes where overcropped, stems were 70%. Currently recommended for limited trial as a pick-your-own berry for the Piedmont and mountain regions. Suggested pollinizers are Powderblue and Tifblue. Released by North Carolina in 1997.
* Brightwell has a reported chilling requirement of 350-400 hours but bloom date occurs with most 500-550 hour cultivars. Brightwell has been one of the most reliable cropping cultivars after the freezes of 1993, 1996, and 1998 in Georgia. Approximate date of ripening in south Georgia is early-mid June to mid July . The harvest period is about 35 days. The berries are medium in size, have small, dry stem scars, and have good flavor and color. Plants are vigorous and upright and can be mechanically harvested for the fresh market with good weather conditions. The berries are round and roll nicely on most packing lines. Frozen berries are reported to have a reddish cast in some years. Brightwell is subject to overcropping and return bloom can be poor if the bushes are not pruned and given good post harvest care. It is at least partially self-fertile. Suggested pollinizers are Austin, Powderblue, and Premier. Released by Georgia in 1983.
Woodard has a chilling requirement of 350-400 hours, blooms early, and frequently suffers freeze damage. Approximate date of ripening in south Georgia is early/mid June to late July. Berries are light blue, large (early in the season) and somewhat soft. The quality of the berries is good when they are fully ripe, but are very tart until ripe. Woodard is a poor choice for fresh market shipping because it is too soft and is not recommended for the process market because the skin toughens when frozen. The plants are shorter and more spreading in habit than most rabbiteyes. No longer recommended in Georgia. Released by Georgia in 1960.
Chaucer has a chilling requirement is 350-400 hours. It is not recommended for mechanical harvesting or for fresh fruit shipments to distant markets due to a wet picking scar. Berries are medium in size. It was released from Florida for pick your own purposes but is rather low chilling for planting in Georgia for this purpose. Plants are vigorous and spreading. Released by Florida in 1985.
Bluebelle has a chilling requirement of 450-500 chill hours, and early blooming often results in freeze damage and partial crop loss. Approximate date of ripening in south Georgia is mid June to late July. Berries are medium-large, round, light blue and have excellent flavor. In years without spring freezes, the berries size well throughout the season and production is high. Fruit tend to tear when harvested, and ripe fruit float with green berries on a "wet line" used in processing berries for the frozen market. Therefore, this cultivar is not recommended for shipping or processing in Georgia. Plants are upright in growth habit and are moderately vigorous. Suggested pollinizers are Austin and Brightwell. Released by Georgia in 1974.
Briteblue has a chilling requirement of 600 hours. Approximate date of ripening in south Georgia is late June to Aug 1. Harvest lasts about 25 days. Berries are light blue, large, very firm with good flavor when fully ripe and can be mechanically harvested for the fresh market with good weather conditions. A problem with stems has been reported in some years. Berries are easily hand picked because they grow in clusters. Mature berries have a long retention on the plant making it an excellent choice for pick-your-own operations. Briteblue is moderately vigorous and grows upright and open. Plants may be slow growing the first few years. Suggested pollinizers are Tifblue, Brightwell, and Powderblue. Released by Georgia in 1969.
Choice has chilling requirement of 550 hours. Approximate season of ripening in south Georgia is late June to late July. The fruit are medium in size with good color, fair firmness, fair picking scar, and good flavor. Choice is vigorous, but is less upright than Tifblue. Although Choice flowers with Tifblue, it suffers less from fruit drop after mild winters in north central Florida. Choice can probably be mechanically harvested for the fresh market in years with good weather conditions and is recommended and for some areas of Florida where Tifblue does not perform well. Information about its performance in Georgia is limited. Suggested pollinizers are Brightwell and Powderblue. Released by Florida in 1985.
Tifblue has a chilling requirement of 600-800 hours and normally blooms in mid to late March in south Georgia. Approximate date of ripening in south Georgia is late June to August 1. The fruit are medium size with average firmness, color, and picking scar, and good flavor. The first picking of Tifblue can be mechanically harvested for the fresh market during good weather conditions. However, most years the fruit ripens too late to receive high fresh market prices. It also has a very serious problem with fruit cracking during wet weather. No longer recommended for commercial planting if Powderblue can be obtained, due to the fruit cracking problem. Plants make vigorous, upright growth. Cane numbers can be excessive and pruning costs for mechanical harvest are significant. It is common for a few of the bushes to die each year in mature plantings. The cause is unknown but might be stem blight. Suggested pollinizers are Brightwell, Briteblue, and Powderblue. Released by Georgia in 1955.
Yadkin has a chilling requirement of about 650-750 hours. Approximate date of ripening in south Georgia should be late June to early August. The fruit are medium in size with a medium blue color, and have an average picking scar and firmness. Yadkin is reported to have good aromatic flavor in North Carolina. It can be mechanically harvested for the fresh market in years with good weather and should be popular with pick-your-own operations, because it bears most of its fruit on the tips. Bush size is smaller than Tifblue. Overcropping may result in poor return bloom the following year. Suggested pollinizers are Brightwell and Powderblue. Released from North Carolina in 1997.
* Powderblue has a chilling requirement of 550-650 hours. Approximate date of ripening in south Georgia is late June to early August. Berries are medium in size, are light blue in color, have a small, dry stem scar, and have good firmness and flavor. Powderblue cracks less in wet weather and hangs on the bush better than Tifblue. It can be mechanically harvested for the fresh market in years with good weather. Powderblue is similar enough to Tifblue in appearance, quality, season and mechanical harvesting characteristics that the two can be harvested together and used as pollinizers for each other. It is an excellent choice to plant in established Tifblue fields to increase pollination. Bush habit it upright and spreading. Suggested pollinizers are Tifblue and Brightwell. Released by North Carolina in 1978.
Baldwin has a chilling requirement of 450-500 hours. Approximate date of ripening in south Georgia is late June to early August. The fruit are medium/large, dark blue, and have a good picking scar, firmness, and flavor. Bush habit is fairly vigorous and upright. Baldwin is a good choice for pick-your-own operations in south Georgia where later season fruit is desired. It is not recommended for the fresh shipping market because it is too dark. Suggested pollinizers are Brightwell, Powderblue, and Centurion. Released by Georgia in 1985.
Delite has a chilling requirement of 500 hours. Approximate date of ripening in south Georgia is early July to late July. The fruit are medium/large, with good color, firmness, picking scar, and flavor. Delite is moderately vigorous, producing an upright plant. Due to leaf disease problems (blueberry rust) and inconsistent bearing Delite is no longer considered for commercial production in Georgia. Released by Georgia in 1969.
Centurion has a chilling requirement of 550-650 hours or more. It blooms late and is self-fertile to some degree. Approximate date of ripening in south Georgia is late June to early August. Fruit are medium sized, medium to dark blue in color, have an average picking scar, and have good flavor. Fruit occasionally cracks following very heavy rains. Bushes are vigorous, very narrowly upright, and have limited suckering. Young plants may be poorly anchored (one-sided root systems) and can fall over in high winds. Recommended for pick-your-own operations where late season fruit is desired. Suggested pollinizers are Brightwell and Powderblue. Released by North Carolina in 1978.
SOUTHERN HIGHBUSH BLUEBERRIES
General Information on Southern Highbush Blueberries
One of the most exciting developments in Southern blueberry culture is underway! In the last five years, many new early ripening Southern highbush blueberries have been released. These cultivars have a lower winter chilling requirement and more heat tolerance than Northern highbush blueberries. Many southern highbush blueberries ripen during the months of April and May in south Georgia, compared to ripening in June and July for most rabbiteye cultivars. Most southern highbush are currently harvested by hand, therefore, fruit size is an important consideration. Cultivars with medium size fruit generally take longer to pick than cultivars with large or very large fruit. Since workers are usually paid by the bucket, they may not want to pick medium size fruit if large size fruit are available.
Southern highbush blueberries are generally difficult to grow as compared to rabbiteyes. Low vigor and high mortality are serious problems when plants are grown on less than ideal sites. The following culture guidelines can greatly improve the chances of success with southern highbush.
Some guidelines for southern highbush culture
* Plant in soils high in organic matter soil (minimum 3%), or amend soil and /or mulch with products such as pine bark or pine pole peelings.
* Provide very good internal soil drainage. This can be facilitated by bedding and ditching around the field.
* Provide permanent irrigation (overhead or micro-sprinklers are best).
* Maintain excellent weed control.
* Apply fertilizer regularly (use smaller, more frequent amounts for young plants).
* Employ control tactics for birds, deer, insects, and diseases.
* Prune established plants annually or semi-annually.
* Since most southern highbush blueberries are only partially self-fertile, they benefit greatly from cross pollination with other cultivars.
Southern Highbush Cultivars
Currently, we can only make an educated guess about which of the southern highbush cultivars will be ideal for your region. The following is a list of Southern highbush blueberries and information currently known about them. The most promising cultivars for the commercial blueberry belt in south Georgia are marked with an asterisk (*). Cultivars are listed in relative ripening order for south Georgia.
(Pat.) Jewel has a chilling requirement of about 100-150 hours so it blooms extremely early in the spring. The harvest season in Gainesville, Florida has been mid April to early May. Fruit size is medium-large with excellent stem scar and firmness. Flavor is good, but slightly tart. The berry is medium blue in color. Jewel is moderately vigorous with a spreading bush habit. It produces a large number of flower buds, but still develops leaves well in the spring. Its main use is expected to be in areas south of Gainesville, FL, where cultivars such as Star and Santa Fe do not get enough chilling for good production. If trying it in south Georgia, plant it in an area with a good overhead irrigation system for freeze protection since the full bloom date will probably be in early to mid February and beginning of bloom in late January. Cross pollination with Misty or Sapphire is suggested. Released by Florida in 1998.
(Pat.) Sapphire has a chilling requirement of about 100-150 hours so it blooms extremely early in the spring. The harvest season in Gainesville, Florida has been mid April to mid May. Fruit size is medium-large with a dry stem scar and good berry firmness. Fruit color is medium blue. Sapphire has good flavor (the berry is sweet with a pleasant amount of tartness). The plant of Sapphire is slightly less vigorous that Sharpblue and requires very good blueberry soil or pine bark bed culture. It sets a large number of flower buds, and especially for the first two years, some or all of the flower buds should be removed in winter to promote more vegetative growth in the spring. Spring leaf development is fairly good, but not as good as Sharpblue. Like Jewel, its main use is expected to be in areas south of Gainesville, Fla. where cultivars such as Star and Santa Fe do not get enough chilling for good production. If you want to try Sapphire in south Georgia, plant it in an area with a good overhead irrigation system for freeze protection since the full bloom date will probably be in early to mid February and the beginning of bloom in late January. Cross pollination with Misty or Jewel is suggested. Released by Florida in 1998.
*(Pat.) Star has a chilling requirement of about 400-500 hours so it blooms late enough to avoid many freezes. Approximate ripening date in south Georgia is late April to mid May. Fruit are large to very large and are fairly firm. Flavor is very good. Fruit may exhibit some cracking in wet weather. Bushes are fairly vigorous and upright-spreading in habit. Star usually has good spring leaf development. It requires cross pollination from other southern highbush cultivars for best production. O'Neal should serve as good pollinizers. Star is susceptible to Septoria leaf spot. Recommended for trial in south Georgia. Released by Florida in 1996.
* O'Neal has an approximate chilling requirement of 400-500 hours for the flowers, and slightly more for leaves. The approximate ripening date in south Georgia is late April to mid May. The bulk of the crop ripens later than Star. O'Neal blooms over an extended period of time, starting very early in the spring. Often one or two flowers per cluster will emerge before the rest of the flowers. O'Neal is productive with large, medium-blue fruit having excellent firmness, picking scar and flavor. It is not currently thought to be machine harvestable. O'Neal is fairly vigorous and semi-upright. Spring leaf development is only fair, but the cultivar is tolerant to some races of stem canker. Recommended for trial in south Georgia. Released by North Carolina in 1987.
Sharpblue has a chilling requirement of about 200-300 hours. Approximate ripening date in south Georgia is early to late May. It is resistant to stem canker, but leaf diseases can be a problem. Sharpblue is no longer recommended for Georgia because it blooms too early, the scar is wetter than desired, and the old blooms often stick to the fruit. Bushes are moderately vigorous, semi-upright, and moderately productive. Fruit are medium/large in size, light blue in color, are fairly firm, have a wet scar, and have good flavor. Released by Florida in 1976.
*Santa Fe (Pat.) has a chilling requirement of about 350 hours, and its approximate ripening date in south Georgia is early to late May. The berries of Santa Fe are medium/large in size, and have an excellent scar and firmness. Fruit color is blue to blue-black and flavor is good. Plants of Santa Fe are vigorous and upright. Spring leaf development is usually good, but is not as good as Sharpblue and Star. Santa Fe appears to have excellent potential for south Georgia on sites with overhead irrigation for freeze protection and is recommended for limited trial. However, the cultivar is difficult to propagate from softwood cuttings, because cuttings tend to defoliate quickly when placed under mist. Best propagation results have been obtained by using very soft, softwood cuttings. Interplant Santa Fe with Star, Southmoon, or O'Neal for cross pollination. Released by Florida in 1999.
Misty has a chilling requirement of about 200 hours, and its approximate ripening date in south Georgia is early to mid May. Fruit quality is good and fruit size is large. Bushes are moderately vigorous and upright with dark green foliage. Misty can have a serious problem with stem blight (Botryosphaeria dothedia) when young plants are fruited too heavily. Also, Misty tends to leaf poorly, and unless spring frost removes part of the crop load, pruning is required to thin heavy crop loads and alleviate plant stress, especially on young plants. Growers in Florida often have to thin the crop by clipping off one-half the tip of the small fruiting branches in late winter. Do not make pruning cuts near the soil surface when the plants are young, because disease can enter the pruning cut. Strip flower buds by hand on the lower twigs. Released by Florida in 1989.
* Bladen has a chilling requirement of about 600 hours, and its approximate ripening date in south Georgia is early to mid May. Fruit ripens about five days ahead of O'Neal. The fruit is medium sized, and has good quality, color, firmness, and picking scar. Bladen has better fruit color and less wet weather cracking than Reveille. This cultivar is probably adapted to mechanical harvest for the fresh market, but hand harvest is currently recommended. Bushes are upright and fairly vigorous with a slightly wider canopy than Reveille. Highly recommended for limited trial. Plant with Reveille or O'Neal to insure adequate pollination. Released by North Carolina in 1992.
(Pat.) Bluecrisp has a chilling requirement of about 400 hours and an approximate date of ripening of early to late May. The fruit are medium-large, light blue, and unusually firm. The fruit scar is dry but medium deep, and the skin tears on some berries when they are picked. Bluecrisp produces a moderately vigorous plant that is more spreading than upright. Flower bud failure during the winter reduces the crop potential of this cultivar some years in the Gainesville, Florida area. In recent years this cultivar suffered from shoot die back in south Georgia. A definitive cause for the die back has not been determined at this time. Post harvest hedging of the bush has been beneficial for removing the dying canes and invigorating the bush. Because of this shoot die back problem, Bluecrisp is not recommended for large-scale planting in Georgia at this time. Released by Florida in 1997.
Reveille has an approximate chilling requirement of about 600-800 hours and ripens in south Georgia in early to mid May during years with sufficient winter chilling. The fruit are medium sized, light blue in color, have an excellent picking scar and firmness, and have good flavor. Reveille is probably adapted to mechanical harvest for the fresh market, but hand harvest is currently recommended. Plants are fairly vigorous and productive with a very narrowly-upright bush habit. Reveille is somewhat difficult to establish as compared to some other southern highbush, which may be due to susceptibility to root rot. Therefore, plant this cultivar in well drained soil or on raised beds (actually recommended for all southern highbush). Fruit cracking has been a problem for Reveille in rainy years. At this time, Reveille is only recommended for limited trial in south Georgia until we learn more about its winter chilling requirement. It appears to be better adapted to the upper part of the south Georgia blueberry belt (Baxley area), than to the lower part of the belt because of it chilling requirement. Released by North Carolina in 1990.
(Pat.) Marimba has a chilling requirement of about 400 hours, but blooms over a protracted period of time. Its approximate ripening date in south Georgia, is early to mid-May. Fruit are firm and have a good scar; however, serious problems with over-cropping and fruit with stems occur in some years. Fruit are small/medium and difficult to pick compared to other Florida cultivars such as Star. Plants are fairly vigorous and bushy, but spring leaf development may be poor. Marimba is not recommended for planting in south Georgia. Released by Florida in 1991.
(Pat.) Southmoon has a chilling requirement of about 400 hours and its approximate ripening date in south Georgia is early to late May. Berries are large, firm, and have a good picking scar. Southmoon requires cross pollination with other southern highbush cultivar for best results. O'Neal, Star, and Georgiagem are suggested companions for cross pollination. Plants in the nursery are vigorous, but plant survival in some fields in south Georgia has been extremely poor. Southmoon is not a good choice for planting in south Georgia. Released by Florida in 1996.
Avonblue has a chilling requirement of 400 chilling hours and its approximate ripening date in south Georgia is early to mid May. This cultivar is semi-upright, but is not very vigorous and is only moderately productive. Fruit are medium/large in size and are light blue in color. Berries have good firmness, a dry stem scar and good flavor. Released by Florida in 1977.
Gulf Coast has a chilling requirement of about 300 hours and blooms too early in many years. Approximate ripening date in south Georgia is mid to late May. The fruit are medium in size, are firm, have a small stem scar and exhibit good flavor. Plant vigor and health are excellent, but Gulf Coast is not popular in Georgia because an excessive number of fruit stems remain attached to the fruit after harvest. Released by Poplarville, MS (USDA Station) in 1987.
Georgiagem has an approximate chilling requirement of only 350 chilling hours, but it blooms in the 500 chilling hour range. Approximate ripening date in south Georgia is mid to late May. Georgiagem is only moderately vigorous, is upright in bush habit, and develops a poor root system on most soils. Overall, productivity is low to medium. Fruit are medium in size with good color, firmness, picking scar and flavor. Georgiagem is probably susceptible to stem bight and canker. This cultivar can be planted with early blooming rabbiteyes for cross pollination. Released by Georgia in 1986.
Cooper has a chilling requirement of 400-500 chilling hours, but blooms in the 700 hour range based on observations. Approximate ripening date in south Georgia is mid May to early June. Bushes are vigorous, semi-upright and moderately productive. Fruit are medium/large in size, and have good firmness, stem scar, and flavor. Stem canker has been a serious problem at the Gainesville, Florida Experiment Station; however, Cooper plants at the UGA Experiment Station in Alapaha are very healthy. Released by Poplarville, MS (USDA Station) in 1987.
Sampson has a chilling requirement of about 800 hours. It is probably too high chilling for south Georgia, but may have potential for middle and north Georgia. It should ripen starting in mid May in upper middle Georgia. Fruit size is large/very large with good color, picking scar, firmness, and flavor. Plants are semi-upright to upright with moderate vigor. Information is very limited at this time. Released by North Carolina in 1998.
Cape Fear has an approximate chilling requirement of 500-600 chilling hours, and its approximate ripening date in south Georgia is mid to late May. The fruit are large, light blue, and have a small picking scar and good flavor. However, the fruit is too soft to handle well for distant shipping. Bushes are vigorous, semi-upright, very productive and precocious. Plants are susceptible to stem canker, but are tolerant to stem blight. Released by North Carolina in 1987.
Flordablue has an approximate chilling requirement of 300 hours and a ripening date in south Georgia of mid to late May. Flordablue is difficult to propagate and grow, and is not recommended for planting in Georgia. Released by Florida in 1976.
* Magnolia has a chilling requirement of about 500 hours and an approximate ripening date of mid to late May in south Georgia. Fruit of Magnolia are medium/large in size, with good flavor, color, firmness, and picking scar. Plants have a spreading growth habit, are medium in height, and are productive and vigorous after field establishment. Small plants require good management during establishment to ensure a stand. Magnolia appears to grow well with pine bark mulch in average, virgin flatwoods soil, and has excellent potential for much of south Georgia with "ordinary" and not spodic soils. Winter flower bud failure has been a problem in Gainesville, Florida and Magnolia has not produced good crops most years on that site. A small degree of flower bud failure (ca. 20%) was observed in Tifton, GA after the mild winter of 1998-99, but Magnolia still produced a good crop. Recommended for limited trial in upper and middle south Georgia. Released by Poplarville, MS (USDA Station) in 1995.
* Jubilee has a chilling requirement of about 500 hours and its approximate ripening date in south Georgia is mid to late May. Fruit of Jubilee are medium/large in size, and have good color, flavor, firmness, and small picking scar. Plants are upright, vigorous and productive. This cultivar appears to grow well with pine bark mulch on average, virgin flatwoods soil. Plants are even doing well in Griffin, GA with pine bark mulch on a red Piedmont soil. Jubilee is recommended for limited trial in south and middle Georgia, and will likely benefit from cross pollination. Suggested pollinizers are Magnolia and O'Neal. Released by Poplarville, MS (USDA Station) in 1995.
Blue Ridge has an approximate chilling requirement of 500-600 hours. Approximate ripening date in South Georgia is mid to late May. Blue Ridge is vigorous, upright and productive. Fruit is large to very large, very light blue with excellent firmness but a wet picking scar. Plants are susceptible to stem canker, but are tolerant to stem blight. This cultivar may have potential in the Coastal Plain, Piedmont and lower mountains in the Southeast, but only for pick-your-own plantings because of a wet picking scar. Released by North Carolina in 1987.
Pearl River has a chilling requirement of about 500 hours and its approximate ripening date in south Georgia is late May to early June. Pearl River needs cross pollination so plant it with another cultivar such as Jubilee or Magnolia. The fruit is medium in size with good flavor and a small picking scar. The fruit color is dark blue and may not be commercially acceptable on some markets. Bushes are vigorous, upright and productive. Because of the potential problem with fruit color it is recommended for only very limited trial until more is known about its marketability. Pearl River is a highbush x rabbiteye hybrid. Released by Poplarville, MS (USDA Station) in 1995.
Summit has an approximate chilling requirement of 800 hours. Summit is a mid to late season southern highbush and should ripen starting about June 5 in upper middle Georgia. Fruit are large, with excellent color and flavor. Berries have a good picking scar and firmness. The bush is semi-upright and moderately vigorous. Information on Summit in Georgia is very limited at this time. Released in 1998 by North Carolina, Arkansas, and USDA.
(Pat.) Ozarkblue has an approximate chilling requirement of 800-1000 hours. It usually blooms several days after Tifblue and several days before Bluecrop in Arkansas. It fruited well in Arkansas following the March 1996 freeze.. It is probably too high chilling for south Georgia, but may have potential in middle and north Georgia. The fruit starts ripening about seven days before Climax in Arkansas. Fruit quality ratings including stem scar, color, firmness, and flavor are high, and fruit size is large. Ozarkblue plants are semi-upright and fairly vigorous, but heavy crop loads can cause canes to have a willow-like growth habit during the fruiting season. Some plants die during establishment, but remaining plants are vigorous after the establishment period. For this reason it is recommended only for very limited trial in Georgia. Released by Arkansas in 1996.
Legacy has an approximate chilling requirement of 500-600 hours. In the Griffin, GA area during 1999, Legacy bloomed with Star and ripened during late May to mid June. The fruit are medium/large, are moderately firm, and have a good stem scar and flavor. The bush is upright and productive, and plants are reported to grow well even on "red clay" in North Carolina. Legacy may have potential for the Piedmont and upper south Georgia. Released by New Jersey (USDA) in 1993.
NORTHERN HIGHBUSH BLUEBERRIES
General Information on Northern Highbush Blueberries
Northern highbush blueberries are generally self-fertile. However, larger and earlier ripening berries result if several cultivars are interplanted for cross-pollination. The chilling requirement for the northern highbush cultivars listed below is at least 1000 hours, unless otherwise noted. However, since they do not tolerate heat well they are generally not recommended for the Piedmont area of Georgia. Since information on northern highbush blueberries in Georgia is very limited, proceed with caution. These blueberries generally require soil highly amended with pine saw dust or milled pine bark plus a pine bark nugget mulch for best results. Overhead irrigation or micro-sprinklers are also recommended. Remember, most northern highbush ripen ahead of rabbiteye blueberries in the mountains. Early season means the harvest starts in early to mid June, mid season means late June, and late season means July. Vigor is also relative. A "vigorous" northern highbush is not as vigorous as a vigorous rabbiteye blueberry in Georgia. The cultivars with the best track record in the mountains of Georgia or North Carolina at this time are marked with an *. Other cultivars are recommended only for very limited trial at this time.
Additional Information
(Pat.) = Patented or patent pending. All future Florida and Arkansas cultivars will be patented to help support the blueberry breeding programs.
Information on propagation of patented Florida cultivars can be obtained by contacting the Florida Foundation Seed Producers, Inc. P.O. Box 309, Greenwood, Fla., or you may call the Foundation office at 850-594-4721.
Information on patented Ozarkblue can be obtained by contacting Dr. James Clark, Dept. of Hort., U. of Ark., Fayetteville, Ark. 72701. Phone: 501-575-2810.
Information on new North Carolina cultivars can be obtained by contacting Mr. Mike Baker at N.C. Foundation Seed, 8220 Riley Rd., Zebulon, N.C. 27597. Phone: 919-269-5592.
Information on new USDA Mississippi cultivars can be obtained by contacting Dr. Jim Spiers at the USDA Southeast Small Fruit Research Station, Box 287, Poplarville, MS 39470. Phone 601-795-8751
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