Growing Blueberries in San Diego County...High chilling requirement, not suitable for Southern California Rabbiteye Native to southern Georgia and northern Florida Low spreading bush,

Growing Blueberries in SanDiego County

Ramiro E. LoboUCC E Farm Advisor

Small Farms & Agricultural Economics

Blueberry ResearchStarted in 1997

UC Cooperative Extension


Why Blueberries?Trends – Health, antioxidants, statusEconomics – New, profitable cropsUnique combination of flavorful fruit andornamental valueRelatively easy to grow, require minimalcareVery little susceptibility to pestsBlueberry plants have a long life

Blueberry Health BenefitsNutrition Great source of vitamin C Good source of dietary fiber

Antioxidants help neutralize Free radicals Cancer & Cardiovascular disease Alzheimer’s

Research indicates that blueberries Make you more agile Make you stronger Make you smarter

Blueberries make you happier!!


Blueberry BiologyFamily: Ericaceae

Same family of cranberries, rhododendrums and azaleas

Genus: VacciniumVarious species grown commercially:

Highbush Blueberry (V. corymbosum) - is most importantspecies of blueberry grown in the US Lowbush blueberries (V. angustifolium) Half High blueberries – cross of highbush & lowbush types Rabbiteye blueberries (V. ashei)


Types of Blueberries

Northern highbush Native to northern and north-east U.S. and Canada High chilling requirement, not suitable for Southern California

Rabbiteye Native to southern Georgia and northern Florida Low spreading bush, does well in acidic, low organic soils Improved varieties from USDA, North Carolina and Georgia Require cross-pollination


Types of BlueberriesSouthern highbush Crosses between northern highbush and native

southern blueberries Good flavor with low chill characteristics Early ripening, commercial potential in Georgia from

April to May (U. of Georgia Extension) Need acidic soils with high organic matter


Blueberries for San Diego?Must have varieties with low chillingrequirementsFruit earlier than in the northern statesThey can withstand cold in winter…andheat in the summerDon’t want them to bloom/fruit too earlyMust manage soil pH (lower to 4.5 – 5.5)


Blueberries for San Diego?

Southern high-bush varieties are suitable forSan Diego (low chill requirements)Plants grown as perennial woody plants, do notneed a trellisFeeder roots are fibrous without root hairs, willnot penetrate compacted clay soilsBees are required for pollinationPruning yearly, new canes needed for fruit


Challenges for CommercialProduction

Lack of supporting infrastructure no packer, no brokers, no grower organizations, no harvesting equipment

Soil pH managementTopography – flat ground necessary formechanical harvestingExpensive irrigation water/limited groundwater supplyHigh initial investment / risky business!


Site SelectionSunny location with good drainageRaised beds recommended if drainage is aproblemCan grow on almost any soil if amendedproperly with organic matter or peat mossincorporated into soil (1 cf/4 plants)Blueberries thrive in acidic soils, soilacidification is necessary

Granular sulphur, pine bark mulch, iron chelates

Grow well in pots


Soil pH

Blueberries do best when pH between 4.5 – 5

Typical pH in our soils is higher than 6 DG soils slightly acidic, with pH of 6.0 to 7.0; Valley soils more alkaline with pH of 7.0 to 7.8

Soil pH management is the most critical factorfor blueberry production Soil needs to be amended to pre-planting pH management a must post-planting


Soil AmendmentsLower soil pH pre-planting byadding 3-5 pounds of sulfur

per 100 square feet

Soil AmendmentsOrganic material

- Pine sawdust, chips, bark,peat moss.

- Apply 6” pre-plantincorporated

- 3-6” topical mulch, reapply asneeded



Mulching

Mulching is critical to keep pH down and tokeep moisture around root system

Mulch suppresses weeds also

Bark mulch (pine bark best), but acid compost,sawdust, and grass clippings all work well

Repeat application on a yearly basis

pH ManagementAfter planting pH management•Sulfur, citric acid, ammonium sulfate fertilizer•Vinegar or Citric acid may be applied during the growing season•Ammonium based fertilizer & acidifying products



Spacing & PlantingSix feet between rows and 30 inches betweenplants optimum spacing

Buy the largest plant available, not the oldestor woodier

Remove plant from pot and break root ball toimprove aeration and watering Plants shock if root ball not broken

Set top soil on plant 1 inch higher than groundand compact well

Planting Blueberries



PruningPlants should be well established before lettingthem to set fruit

Remove blooms the first year/grow root system

Once established, remove the nursery plant inthe second year (brushy growth)Should prune heavily after fruiting season(remove old wood that fruited)Light prunning in late winter to remove weakshoots, crossing branches or low growth


FertilizationRhododendron or azalea formulations workwell with blueberriesFor young plants, use 2 tablespoons of 10-20-20 in early and late springIncrease amount of fertilizer by one ounceyearly up to 8 ounces/yearDo not over-fertilize…may end up with lushgrowth and little fruitMonitor leaf color…if reddish, need to work onsoil pH.


PropagationPropagated by both hardwood and softwoodcuttingsHardwood cuttings mostly used, they areeasier to handle and less perishableShoot selection is critical for success

Well-hardened, unbranched, one-year old whips ! ” in diametershould be selected

Several rooting media can be used include sphagnum moss, American, German or Canadian peat,

sawdust, sand, perlite and vermiculite

Propagation also done by seeds and grafting


“Chilling Requirement”“Defined as the number of hours of wintertemperatures 45 degrees F and below thatplants must be exposed to for 90% of the budsor blooms to open and develop normallyfollowing a two week period of exposure towarm weather.”

200-300 hour cultivars mid-late Feb,400-500 hour cultivars early-mid March600-800 hour cultivars late March -April


Varieties?Distinguished for climatic requirementsand ripening seasonSelect the right varieties for your micro-climateSelect varieties that fruit at differenttimes and produce different size fruitBushes with different shades of color andgrowth habitsPlant two plants per family member


Cultivars – Sharpblue (200)Early producer, medium sized fruit,blooms & fruits year round


Cultivars – Misty (200)Early, vigorous, prolific, large number offruit, may require thinning


Cultivars - Jewel (200)Early mid season, large, tangy fruit


Cultivars - Emerald (250)Mid season,large roundfruit, spreadingbush (mayneed trellis)


Cultivars - Southmoon (500)Mid to late, exceptional flavor


Cultivars - Star (400-500)Early, excellent flavor,upright plant


Cultivars - O’Neal (500-600)Very early, excellent flavor,great flavor (best among SHB)


Other CultivarsSapphire (200–300) - Early, medium vigor,medium fruit

Millenia (400-500) - Mid season, large fruit,good flavor, vigorous, spreading bush

Santa Fe (400) - Early, great flavor, vigorousupright bush

Rebel (400-500) - Mid season, vigorous,precoscious, large fruit


Blueberry Tasting

ENJOY!!

Questions??


THE END!!Ramiro Lobo & Gary Tanisaki

UCCE San Diego County – Farm and HomeAdvisor’s Office

Phone: 760.752.4724Email: [email protected]

WWW: [email protected]

Documents

Growing Blueberries in San Diego County...High chilling requirement, not suitable for Southern California Rabbiteye Native to southern Georgia and northern Florida Low spreading bush,