Growing Blueberries
GROWING Blueberries
THE PLANTING SITE: Selecting and preparing
For successful blueberry growing, the soil must be acidic and have lots of organic matter. Choose an area with rich loam or sandy loam soil. In clay soils, it is ideal to add sand, composted mulch or organic matter to the site. Work up the area well so there is ample loose soil. Provide good drainage. Slightly ridging up or berming the planting row is beneficial.
Important! The pH of the soil should be in the 4.5 to 5 range. Add a form of sulfur to establish the correct pH.
SPACING
Space plants 4’ to 5’ apart; rows 8’ to 10’ apart.
PLANTING
The roots can dry out very quickly. Never allow them to become dry at any time. If possible, soak the roots briefly before or during planting. Keep moist during planting. Do not plant too deeply. Cover the roots with 1” of topsoil. Water well after planting, then cover with 4” to 6” of bark mulch, wood chips, oak leaves, pine needles, or similar material to retain moisture. Replenish the mulch as it breaks down.
IRRIGATION
Blueberry plants need continued moisture after planting. A good rule is to apply 2” of water per week while fruit is on the plant. During the early years of plant establishment and post harvest for mature plants, 1” per week is usually sufficient unless there is a drought. Irrigation water should be pH corrected. (Use sulfuric acid or similar)
FERTILIZING
Do not fertilize at planting. Make your first application 3-4 weeks after planting. Apply 2 oz. of ammonium sulfate per plant. Water with pH reduced water (pH 4.5). Use vinegar, sulfuric acid or suitable acidifier. Always use pH corrected water. Most tap water is in the pH 7 range.
In years 2 and more, make 3 applications of 2 oz. fertilizer application. Make the first application at bud break (Apr. 1) application two, a month later (May 1) and third one, around June 1. A total of 6 oz. per season. Mature plants may receive as much as 8 oz. per season. Other forms of nitrogen that can be used are blood meal, cotton seed meal or similar natural plant food.
Ammonium sulfate (nitrogen and sulfur) helps balance the pH ratio needed for blueberries.
PRUNING
Blueberries require less pruning than most other fruits. For the first seven years, remove only weak, broken, or overlapping branches. Once the plant reaches maturity (about eight years) remove one or several main branches at ground level each year to encourage new growth.
CARING FOR YOUR BLUEBERRY PLANTING
THE FIRST SEASON
Removing Blossoms
Blueberry plants will start developing blossoms on one-year-old wood. It is advisable to remove all blossoms the first year after planting.
PROVIDING FOR WEED CONTROL
Mulch
Immediately after planting, provide a form of mulch protection around the plants. Composted sawdust, wood chips, pine needles, or other similar composted material is ideal. This serves for good weed control, but also provides a sheltered, moist environment for the root zone.
Fresh sawdust can be prepared by adding a small amount of nitrogen fertilizer to assist the process of composting. Add mulch yearly if needed.
PLASTIC OR GROUND COVER FABRIC
Most covers, other than natural compost mulches have not been highly satisfactory. Plastic-type covers tend to develop a compacted, caked soil that is not enriched by active soil microbes and earthworm activity.
PLANT HEALTH AND SURVIVAL
Plant Stress
Don’t let your plants dry up! Lack of watering, or insufficient rainfall; simply, not enough moisture, accounts for 90% or more of the plant failure in blueberries the first growing season.
It is important to remedy the problem with immediate action! Use low pH water (4.5-5.5 pH). This can be achieved by adding several tablespoons of vinegar or a very small amount of sulfuric acid (battery acid) to each gallon of irrigation water. Provide irrigation or multiple weekly waterings during dry summer stress periods.
Iron Chlorosis
Check for any yellowing on the leaves. This is often a symptom or a chain reaction of insufficient moisture, lack of iron and a too high pH in the soil. Foliar applications of iron, and fertilizer, along with a rigid low pH watering routine can save the plants and help them to thrive again.
Pruning
Generally, there is not a lot of pruning on blueberries the first couple years. Remove any dead or broken branches. Prune off the lower horizontal branches. Thin out old, weak wood. (Berries form on strong, younger one-year-old wood)
In pruning a mature plant (7-8 years or older) the main principle is removing entire older canes at ground level, to promote young shoots to emerge. For the average bush it will mean cutting out 2-3 older ones and several cuts to eliminate weak, older branches. Not that difficult at all!
Phomopsis Canker
Compared to many fruits, blueberries can be grown with very little or no spraying. In certain areas of the Midwest and eastern U.S., certain cankers can cause major dieback and seriously hinder growth on blueberries. A dormant spray routine similar to peaches is recommended for control.
Courtesy of Schlabach's Nursery. For more information, we recommend David Schlabach's book, Backyard Fruit Production, which we have available for purchase.