Serious Plant Care

Blueberry Hills Farms It's about friends. It's about family. It's about time. Isn't it?

1315 Washington Street . Manson . WA 98831 509.687.2379 wildaboutberries.com

Planting & Caring for Blueberry Bushes

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SITE SELECTION AND PREPARATION
Select a sunny location in well-drained soil free of weeds and well worked. Locate in an area where irrigation water is available, as best results will be obtained by keeping the root zone moist throughout the growing season. Where the soil is poor or marginally drained, raised beds 3-4 feet wide and 8-12" high work very well for blueberries.

A fail-safe way to grow blueberries in almost any soil is to incorporate peat moss into the planting medium. For planting directly in the ground, work up a planting area approximately 2-1/2 feet in diameter and one foot deep. Remove 1/3 to 1/2 of the soil. Add an equal amount of pre-moistened peatmoss and mix well. One 4 cubic foot compressed bale will usually be sufficient for 4-5 plants. For raised beds, mix equal volumes peat moss with acid compost or planting mix. Blueberries thrive in acidic soils. Your garden center representative can recommend a soil acidifier if necessary for your area.

SPACING    Blueberries can be planted as close as 2-1/2 feet apart to form solid hedgerows or spaced up to 6 feet apart and grown as individual specimens. If planted in rows, allow 8 to 10 feet between the rows depending on equipment used for mowing or cultivating.

PLANTING   For container stock, remove from pot and lightly roughen up the outside surface of the rootball. Set the top soil line of the plant about 1-2 inches higher than the existing ground and firm around rootball. Mound soil up along sides of exposed root mass. Water in well.

MULCHING     Blueberries do best with a 2-4" mulch over the roots to conserve moisture, prevent weeds and acid organic matter. Bark mulch, acid compost, sawdust, grass clippings, etc. all work well. Repeat every other year.

PRUNING     It is important that blueberries get established before allowing them to bear fruit. Thereafter, they should be heavily pruned each year to avoid over-fruiting which results in small fruit or poor growth.

Remove all blooms, as they appear the first year. In years thereafter, follow these steps after the leaves have dropped.

1.  Remove low growth around the base. If it doesn’t grow up, it gets pruned out!

2.  Remove the dead wood, and non-vigorous twiggy wood. Select for bright-colored wood with long (at least 3 inch) laterals. Remove blotchy-colored short growth.

3.  If 1/3 to 1/2 of the wood has not been removed by the above steps, thin out the fruiting laterals and small branches until this balance has been obtained.

FERTILIZING Blueberries like acid fertilizers such as Rhododendron or Azalea formulations. For newly planted stock, use 2 tablespoons of 10-20-10 (or similar fertilizer) in late spring or once plants are established. (Careful! Blueberries are very sensitive to over fertilization!) For subsequent years, use 1 ounce of fertilizer for each year from planting to a total of 8 ounces per plant. Apply in early spring and again in late spring for best results. Always water well after fertilizing. Remember not to fertilize after the 4th of July – your bushes need time to go dormant before Fall.

For organic fertilizers, blood meal and cottonseed meal work well. Avoid using fresh manure. It’ll burn the plants.

SHOPPING CHECK LIST

Blueberry Plants (2 per family member )
Peat Moss (4-5 plants per bale)
Mulch (1 cu. ft. per plant)
Fertilizer
Soil Acidifier

HERE'S WHAT THE UNIVERSITY OF MICHIGAN HAS TO SAY ON THE SUBJECT

Selecting the Site

Avoid "Frost Pockets"

Late spring frosts can severely damage flowers and reduce yields. Avoid low-lying areas surrounded by woods or hills these "frost pockets" tend to collect cold air. Higher sites with a gently slope have greater air circulation and are less prone to spring frost damage. Air movement also suppresses certain fungal diseases and provides more comfortable picking conditions during hot weather.

Soil Requirements

Blueberries have very specific soil requirements, but all these soil types tend to be acidic and sandy with a varying organic content.

Organic Matter: The soil should be high organic matter. Organic matter increases the water-holding capacity and improves the aeration of soils. Blueberries have fibrous, shallow roots that are sensitive to soil compaction and poor drainage. During the growing season, water standing on the surface for one or two days can damage roots. Avoid planting on heavy soils that drain slowly. Soil organic matter can be increased in small plantings by incorporating peat, bark mulch or straw but this is usually impractical in larger plantings.

Soil Moisture: Ideal soils are well drained with a water table 14 to 22 inches below the surface. These soils provide a constant, moderate water supply through the season but pose few problems with standing water and water logging.

Even on the best sites, dry seasons frequently reduce growth and yields. Many Michigan growers now irrigate to avoid drought stress. Both overhead sprinklers and trickle irrigation systems are used. The costs of establishment and potential benefits of irrigation are difficult to compare, but plantings on sandy soils low in organic matter will benefit most from irrigation. Overhead systems provide added benefit of frost protection, which trickle systems cannot provide.

Soil pH: Blueberries require acid soil with pH below 5.5, and they do best where the pH is between 4.5 and 5.0. Test the soil pH before planting blueberries. (Consult your County Extension Service for instructions.)

Variety Selection

Highbush blueberry varieties vary in growth habit, disease resistance, berry characteristics, harvest season and yield potential. Choose varieties suited to your region and intended use.

Although highbush blueberry varieties are generally self-fruitful, using two or more varieties that ripen at different times will lengthen the harvest season. A long harvest season may be particularly helpful if you’re growing fruit for the pick-your-own market. Harvest season and other important traits of varieties that perform well in Michigan are listed in Table 1.

Northland and Patriot are hardy crosses between highbush varieties and lowbush blueberries. They are "half-high" types that perform well in colder regions where snow cover provides protection during winter. Though the buds and wood of these varieties may tolerate midwinter temperatures as low as –30 degrees F, they have several drawbacks. Patriot blooms very early and is often damaged by spring frosts. Northland requires extensive pruning, and its fruits are small and soft. The University of Minnesota has recently released several promising half-high cultivars, but they have not been extensively tested and cannot be recommended yet for commercial use.

Establishing the Planting - Preparing the Soil

Test the soil and adjust soil pH to 4.5-5.0 before planting. If the pH is below 4.0, incorporate finely ground dolomitic limestone, following rates recommended on a soil test report (usually 1 to 2 tons per acre).

If the pH is above 5.1, acidify the soil with elemental sulfur. It will require 450 to 900 lb sulfur per acre to lower the pH one unit, e.g., 5.5 to 4.5. Use the higher rate on heavier loam soils high in organic matter and the lower rate on light sandy soils low in organic content. It is usually not economically practical to acidify organic soils with a pH higher than 5.5 or 6.0. If the pH in established plantings is slightly over 5.0, continued use of ammonium sulfate fertilizer will gradually reduce it.

Planting

Obtain plants with a State Certification of Inspection from a commercial grower or reputable nursery. High quality, disease-free plants establish more readily and live longer than diseased or weak plants. Two-or 3-year old bare-root or container-grown plants are recommended. Older plants are usually larger and more expensive and may require some pruning to establish quickly. Younger plants are more difficult to manage.

Set plants in the fall or early spring as soon as the soil can be worked. Space plants 4 to 5 feet apart in the row on less fertile mineral soil or 5 to 6 feet apart on organic soil. Rows should be spaced to accommodate equipment, usually 10 to 12 feet apart. Set plants 1 to 2 inches deeper than they were grown in the nursery. Plants may establish more quickly on sandy soil if a shovel full of acid peat is mixed in each planting hole.

Water Management

Blueberries have a shallow, fibrous root system. Although the costs and returns of irrigating blueberries in Michigan have not been fully studied, most plantings—particularly those on well-drained sandy soil—will benefit from irrigation during dry seasons. Drought conditions during fruit development will reduce berry size, and drought stress in August or September may reduce flower bud development and yields the following year. Drought at any time during the growing season adversely affects vegetative growth.

Overhead sprinklers are the most common method of irrigation, but some growers use trickle irrigation systems. Overhead systems provide the added benefit of frost protection.

Apply enough water during each irrigation to moisten the top 12 to 16 inches of soil at a rate slow enough to allow water to drain into the soil without puddling on the surface. Extension bulletin E-1110, "Irrigation Scheduling for Field Crops and Vegetables," provides more detailed information on irrigation scheduling.

Mulches

Mulch materials such as sawdust, bark, wood chips, straw or leaves spread 6 to 8 inches thick under bushes will conserve soil moisture. These may be effective in small plantings but too costly or difficult to obtain in sufficient quantities for large plantings. Use only weathered sawdust, bark or wood chips—fresh materials may injure plants. Mulched plantings may require two to three times as much nitrogen fertilizer as unmulched plants until the mulch has decomposed.

Fertilizing
The fertilizer program should encourage growth of vigorous shoots, which produce more flower buds and larger fruit. Blueberry soils and fertilizer requirements vary considerably. General recommendations are describe here.

Fertilizing New Plantings
Sample the soil a year before planting and adjust the pH to 4.5-5.0 before planting. This will allow adequate time for sulfur to react in the soil. Four weeks after planting sprinkle about 1 ounce of 20-0-10+5 (N-P-K-Mg) or a similar analysis fertilizer within 12 to 18 inches of each plant, but not directly on the crown or stems.

Fertilizing Established Plantings
Nitrogen (N): In most plantings, N is the only element required each year. Amounts required depend on plant age and soil type and are summarized in Table 2. Use urea (45 percent N) if pH is below 5.0 and ammonium sulfate (21 percent N) if pH is above 5.0. Do not apply nitrate forms of N, such as calcium nitrate, or fertilizers containing chloride.

Apply fertilizer in a broad strip on both sides of plants just before budbreak. Use split applications on sandy sites—apply half the rate just before budbreak and half at petal fall.

Potassium (K): Michigan blueberry soils are rarely deficient in potassium. Apply potassium if the soil test level is below 100 lb K/acre (Table 3) or if leaf analysis indicates a need.

Potassium can be applied as a 2:1:1 complete fertilizer that supplies the recommended amount of nitrogen or as Sul-Po-Mag (22 percent K2O) or potassium sulfate (50 percent K2O). Avoid muriate of potash, which contains chloride and can be toxic to blueberries.

Phosphorus (P): A phosphorus deficiency has not been reported in Michigan blueberries. Use superphosphate (46 percent P205) before planting to bring the soil test level to 100 lb P/acre if soil analyses indicate a need.

Calcium (Ca): Calcium deficiencies have not been reported. If leaf analysis indicates a shortage and pH is below 4.5, apply 500 to 1,000 lb/acre dolomitic lime.

Magnesium (Mg): Magnesium deficiencies occur occasionally in Michigan blueberries. If soil tests or leaf analyses indicate a Mg shortage, apply magnesium as dolomitic lime at 500 to 1,000 lb/acre if pH is below 4.5, or as magnesium oxide (55 percent Mg), Epsom salts (18 percent Mg) or Sul-Po-Mag (11 percent Mg) if pH is above 4.5.

Micronutrients: Micronutrient deficiencies are uncommon in Michigan blueberries when pH is in the proper range (4.5-5.0).

Pruning

Blueberries require regular pruning to produce high yields of large fruit. Unpruned bushes usually contain a disproportionately high percentage of old canes decline in vigor and fruitfulness and too few young replacement canes. Bushes pruned at irregular intervals produce many small canes that must be thinned. The most fruitful canes are 4 to 6 years old and 1 to 11/2 inches in diameter at the base. Bushes should contain about 15 to 20 percent young canes (less than 1-inch diameter) and 15 to 20 percent old canes (2 inches), and 50 to 70 percent canes of intermediate size.

Blueberry bushes are best pruned when dormant, in either late fall, winter or early spring. Spring pruning is usually preferred because canes injured during the winter can be identified and removed. Bushes pruned before leaves fully drop in the fall may bloom a day or two later than bushes pruned in the spring.

Pruning Young Bushes
Young bushes require little pruning for the first three years. Remove damage branches and less vigorous, spindly growth around the base of plants to encourage vigorous upright growth. If possible, remove flower buds also so that young plants use their resources for growth rather than fruit production. Buds may be stripped by hand or pruned off, though either practice is often impractical in large plantings.

Pruning Mature Bushes
Mature bushes should be pruned annually. Follow these general steps:

    1.     Remove branches injured by winter weather or machinery and diseased canes.

    2.     Remove fruiting branches that are spindly or less than 1 foot from the ground. Fruits at ground level are difficult to harvest.

    3.     Remove one or two of the oldest canes and any branches that are low in vigor. (Low vigor canes produce thin, twiggy growth with few flower buds)

Pruning should be used to manage bush size and shape to facilitate picking, fertilizing and spraying. Blueberry twigs require at least 15 percent of full sunlight to initiate flower buds, so varieties that develop thick upright growth need to be opened to sunlight. Several of the large canes on the interior of dense, upright bushes of varieties such as Jersey and Rubel usually need to be removed. Varieties that have a sprawling, open growth habit, such as Berkeley and Bluecrop, should be pruned to keep the bush shape more upright and compact. Varieties such as Blueray and Northland may produce too many new canes each year. and become overcrowded if they are not thinned

Bushes harvested by pick-your own (PYO) should be pruned so that fruits are easy to see and reach. Keep the bush interior open. Remove tall or difficult to reach canes or head each back to a vigorous side branch. Remember that heavily pruned bushes compensate for fewer fruits by producing larger berries. Larger fruits are usually more desirable for fresh or PYO marketing.

Pollination

Though blueberries are self-fruitful and will set commercial crops without cross-pollination, some studies show that flowers receiving pollen from another variety will produce larger, earlier ripening fruit. Yields from large plantings of single varieties may not be as great as yields from multiple variety plantings.

Blueberries require bees for pollination and fruit set. Though native bees may adequately pollinate small plantings, most commercial growers place honeybee hives in plantings for optimum fruit-set. During average years, two large hives per acre appear to be adequate, though benefits can be gained from as many as four hives.

Bees do not work effectively during cool (cooler than 55 degrees F), windy or rainy weather. If these conditions occur during bloom, applications of gibberellic acid (commercial product "Pro-Gibb) made at late bloom according to label instructions may increase fruit-set. Sprays have little effect during years when pollination conditions are good.

Weed Control

New Plantings
Control perennial weeds and grasses before planting blueberries using systemic, nonresidual herbicides at the recommended rates. Growing rye or other cover crops for one or two years prior to planting blueberries will also reduce the number of weeds and add organic matter to the soil.

Avoid using herbicides the planting year—they may injure young plants. Control weeds emerging the first year by cultivating. Avoid cultivating deeper than 1 to 2 inches—deeper cultivation may injure shallow blueberry roots.

Established Plantings
Herbicides and cultivation can be used for weed control in older plantings. Weeds growing between rows during the first part of the season are usually controlled by cultivating or using sods. Often cover crops such as oats, rye or Sudan grass are sown between rows after harvest. This suppresses late-season weeds and tends to harden blueberry bushes for winter and stop wind erosion.

Harvesting
Blueberries usually ripen over several weeks and require two to four pickings to harvest. Hand harvested fruits are picked once per week during most years or more frequently during hot weather. Machine harvested bushes are usually picked when 60 to 70 percent of the fruits are blue and again 10 to 14 days later. Harvest may begin in early July and extend into September, depending on the variety, weather and location.

To pick by hand, gently roll berries between your thumb and forefinger, removing fully ripe berries and leaving unripe berries for the next picking. A picker can collect berries in an open container attached to a belt or cord at waist level. This frees both hands for picking.

Site thrown together with recklessness & wild abandon by BLUEBERRYKARI on 05/12/2008