Top nutrient tips for growing cranberries
Growing cranberries can be a unique challenge. As they prefer sandy, acidic, peat soils, applying fertilizers several times a year is necessary to grow a good crop. Growing cranberries can be an intensive, long process (taking up to three years to start), so patience is a virtue. On top of that, cranberries grow in very unique conditions. They grow in beds of peat, sand, gravel and clay, and will grow in bogs found mostly in the Northeastern United States.
While growth for most plants and crops would be difficult under these conditions, cranberries thrive, and with proper care, some cranberry plants can be grown for over 100 years. To get the most out of your cranberry crops, we’ve provided a few best practices regarding fertilizer and growing tips for this fantastic fruit.
Because cranberries are perennial crops, nutrition is stored from previous generations, making it difficult to determine nutrient deficiencies in the soil. Soil testing can help determine soil pH, as cranberries thrive in low pH soils. Tissue testing in conjunction with standard soil testing is beneficial in determining target fertilizer ranges. Soil should be tested every three to five years and tissue every two to four years, with results stored and measured year-over-year.
Establishing healthy vines
Growing cranberries can take up to three years, so fruit production is not expected in year one. A healthy dose of phosphorous at the time of planting will help increase the growth of new vines, and a controlled release nitrogen is also key. Agronomists recommend fertilizing every two to three weeks until mid-August, stopping in the late summer to allow plants to harden off. This process may be repeated the following year, and much of the next, but the plants will start to bear fruit by the third and fourth years. Use an alternating schedule of ammonium sulfate and an NPK fertilizer throughout the process (levels will vary based on numerous factors).
Cranberries’ unique nutrient needs
When it comes to specific nutrients, NPK levels will vary from bog to bog. Nitrogen levels can be determined based on several factors including soil and tissue test results, vine appearance, weather conditions and previous response to N application levels. Using the lowest viable nitrogen output is important, as high levels can lead to poor fruit growth and rot.
Phosphorous levels can vary depending on tissue samples. If levels are already high, a low phosphorus number is recommended, as high levels can lower water quality.
Potassium, in combination with other nutrients such as magnesium and calcium, should be well balanced, as too much of one can lead to a deficiency of another. Fertilizer application as a whole will be determined on a number of other external factors such as time of year, soil temperature, moisture levels, current crop density and if the bog has had a recent sand application.
Working with your soil type
As the sandy soils in bogs do not hold nutrients very well, several applications of fertilizer may be necessary per year, but in smaller quantities per round. Practically all soils in the coastal plain are in a secondary- and micronutrient-deficient area, so unless a good available secondary and micronutrient source is supplied in your fertilizer, your crop may suffer. The best source for these nutrients is with a fertilizer that can give you uniform coverage in the fields like Rainbow Plant Food.
About Rainbow Plant Food
The chemically homogeneous compound of Rainbow Plant Food ensures the same amount of each micronutrient is present in each individual granule, which are all uniform is size, shape and weight, ensuring a consistently healthy crop. The nutrients exist in a highly available water-soluble sulfate form, so action is quick on roots for your cranberries.
To learn how Rainbow Plant Food is made, click here
For fruit and vegetable application recommendations, click here
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