Let new blueberry plants grow for two or even three years before allowing them to set fruit.
In response to strong market demand for fresh, local blueberries, many growers in Pennsylvania, both established and beginning farmers, are putting in new plantings of this crop.
Blueberries have a lot going for them as a new or expanding crop:
- strong sales
- few pests
- ease of management
- long picking season
- good shelf life (at least for a berry!)
However, in the haste to reap these benefits, growers may be tempted to cut some corners in those first few years of establishing a blueberry planting.
Follow these crop establishment recommendations, all of them, to get the most out of your crop over time. Full details can be found in the Mid-Atlantic Berry Guide for Commercial Growers.
Choose a site that is protected from late frosts, as these can injure flowers and young berries. Lighter-textured soils that are well drained but not droughty; high in organic matter; low in pH; and low in calcium are highly preferred.
Managing pH and organic matter
Begin soil testing and soil preparation one to two years before planting. Few areas in Pennsylvania can support blueberries without considerable soil amending prior to planting. Almost always, sulfur will need to be applied to lower pH to the optimum range of 4.5 to 5.0. It takes time, at least one full growing season, for sulfur to react in soils to start lowering pH. Organic matter additions are also beneficial, especially in our heavier soils.
Blueberries are typically planted in the spring as soon as soil can be worked. Add a gallon of some type of composted organic matter or peat to the planting hole, but avoid mushroom compost due to its high pH. Water immediately. Newly set plants should show a flush of growth about two weeks later; once they do, make an application of ammonium sulfate at the rate of 48 lbs ammonium sulfate per acre. On a per-plant basis, at a standard spacing of 5' x 9', this works out to only 1.5 tablespoons of ammonium sulfate per plant. The fertilizer should be applied in a band around the plants, staying about six inches away from the stems. Be careful not to over-apply, as blueberry roots are easily burned by excess fertilizer. Mulch plants well with rotted sawdust, bark mulch, or chopped corncobs.
Flower buds should be rubbed off of blueberry plants immediately after planting them in the establishment year. Now, here comes the hard part. The Mid-Atlantic Berry Guide for Commercial Growersstates:
...also, completely remove the flowers from plants during their second year so plants become well-established. Sacrificing this small amount of fruit is well worth the dividend of establishing a planting that will fruit for 50 years or more if well-maintained. Some of the crop should also be removed the third year, again encouraging sound establishment.
I have seen several second-year blueberry plantings lately that were not flower-pruned. Stunted but covered with berries, they struggle to produce enough leafy growth to support their heavy fruit load. This imbalance will likely set the crop back for several years.
Blueberry roots do not grow very deeply in the soil, and therefore they are very susceptible to drought stress, especially during establishment years. Drip or overhead irrigation should be used to provide at least an inch of water per week during rain-free periods.
Blueberries are long-lived plants. It is worthwhile to take the time during establishment to make sure that all plant needs are being met.