Posted by Brent Wilson on 9/2/2016 to Fertilizing & Watering Tips
Feeding blueberry bushes is quite simple. Follow the basic tips and instructions below.
Important! Avoid fertilizing a blueberry bush with fertilizers that contain a nitrate form of nitrogen as this will damage roots.
How and what you feed blueberry plants will depend on their age and soil conditions.
First, Soil pH is Important!
Blueberry plants require a very acid soil ranging from around 4.8 to 5.2 on the pH scale. Most average garden soils fall between a pH range of 6.0 to 7.0, meaning you might need to test soil pH before planting and make adjustments if necessary to correct soil pH. If your soil is too alkaline your blueberries won't thrive and produce fruit.
Testing Soil pH
Soil pH is a measurement of the alkalinity or acidity of soil and is measured on a scale of 1-14, with 7 as the neutral mark. Any measurement below 7 indicates acid soil conditions, and anything above 7 indicates alkaline.
If you're unsure about the pH of your soil, or whether or not it is suitable for growing blueberry plants, it's a good idea to test the pH in the planting area. You can quickly test soil pH with an inexpensive soil pH tester probe. To raise the pH (make more alkaline) you can add pelletized limestone to the soil. To lower the pH (make more acid) you can apply Soil Sulfur, Aluminum Sulfate, or Chelated Iron. Adding organic compost to the soil at planting time and regularly as a mulch can also help to increase acidity and maintain acid soil conditions.
Learn More: What is Soil pH and How To Adjust It?
Young Plants (1 year old)
Avoid feeding a newly planted blueberry bush until new growth begins to emerge during the first spring. At that time, I recommend fertilizing with a mild organic plant food, preferably one that contains iron and or sulfur. Spread the fertilizer atop and just outside the perimeter of the root ball.
Established Blueberry Plants (2+ years old)
Once established, blueberries like acid-forming fertilizers such as an azalea food, or an organic plant food, preferably one that contains iron and/or sulfur, which help to maintain an acid soil. Since blueberries are very sensitive to over-fertilization, take care to not to apply too much fertilizer. Follow label instructions.
It's best to fertilize once in early spring and again in late spring, spreading the fertilizer under and around the drip line (the perimeter of the branches). This is where the heaviest concentration of feeder roots will be. Avoid using manures as they can damage the plants. Be sure to always water thoroughly after fertilizing.
From the third season on base the amount of fertilizer applied on the size of the bushes. Follow application rates on product label and be sure to spread the fertilizer evenly under and around the bushes
How To Water Blueberry Plants
Blueberry plants prefer a consistently moist, but not a constantly soggy or wet soil, which could be problematic. So make sure the planting site is well-drained.
At Planting Time
Immediately after planting deep soak the soil in the planting area, including the root ball, to a depth equal to the height of the root ball or at least 6 inches. An application of Root Stimulator will provide an extra boost to stimulate early root formation and stronger root development. Root Stimulator reduces transplant shock and promotes greener, more vigorous plants.
During the First Active Growth Season
In average garden soil you should not have to water your newly planted blueberry plants every day. More often than not, this causes soggy or wet soil conditions that can lead to root rot and other plant diseases. In the absence of sufficient rainfall, water only as needed to keep the rootball and surrounding soil moist. Apply an organic mulch to help retain moisture and reduce hand-watering. Keep in mind that deep soaking less frequently is much better than splashing just a little water on the plants every day. Plants planted during the winter dormant season, when not actively growing and evaporation is much slower, will require much less water. So, be careful not to overwater during winter!
When established, blueberry plants will require less water, however will prefer a consistently moist soil, especially when there is fruit on the plant. Keep plants mulched well to help retain moisture.
Other Helpful Tips
Water blueberry plants throughout the growing season when rainfall is not adequate. Irrigation of young plants is especially important. Adequate water is essential for plant growth and important for fruit bud formation that occurs in the fall. This being said, as with so many other plants, blueberries do not like a constantly soggy or wet soil. Just keep the soil moist, especially when there is fruit on the plant.
Mulching with a 2-inch layer of aged compost or pine straw helps to retain moisture and suppress weed growth. As the mulch decomposes it will add vital nutrients to the soil that your plant will appreciate. Do not use freshly chipped or shredded wood for mulch until it has cured in a pile for at least 6 months, a year is better. Avoid placing or piling mulch directly against the base of the shrub as this could cause problems with the bark.
Never over-fertilize blueberry bushes as too much fertilizer damages them easily. If you use an organic fertilizer there won't be the worries about burning your plants.
Plant Long & Prosper!™
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