Blueberries are a delicious and nutritious food. Taking care of your blueberry bush requires fertilizing it. Here is the best way to keep your blueberry bush healthy and productive.
Why Fertilize Blueberries?
Blueberries are heavy feeders year after year. Soil becomes depleted of nutrients faster than they are replaced. If you do not fertilize your blueberries, they will not produce much fruit.
In addition, blueberries like the soil pH to be 4-5.5. Most soils are not that acidic, so the correct fertilizer makes the soil more acidic.
How Do I Know If My Blueberries Need Fertilizer?
All blueberries need fertilizer. Without fertilizer, your blueberries will be stunted and slow to grow. They will produce small crops or no crops at all. The leaves may become yellow.
What Nutrients Do Blueberries Need?
Blueberries need the same sixteen elements that other plants do.
Briefly, carbon, oxygen, and hydrogen come from the air and water.
Nitrogen, phosphorus, and potassium are needed in large quantities and are the numbers on fertilizer bags.
Nitrogen is used in every cell in the plant and is essential for growth.
Phosphorus helps a plant convert sun energy into energy the plant can use. It is also associated with blooming and setting fruit.
Potassium is essential for photosynthesis. It helps a plant grow vigorously and healthy.
Calcium, magnesium, and sulfur are needed in lesser quantities. Micronutrients are also necessary. They are boron, copper, iron, manganese, molybdenum, zinc, and chlorine.
Blueberries can’t grow and produce lots of fruit without all of these nutrients in the correct amounts.
What Type Of Fertilizer Do Blueberries Need?
All blueberries need nitrogen. A soil test will tell you what other nutrients they need.
In my area, we have plenty of phosphorus and potassium in the soil, so I would not add those. If phosphorus and potassium are scarce in your soils, you will need to add them. If the pH is too alkaline, you will need to add sulfur to lower it. You may need to add iron as well.
However, too much of a nutrient is as bad or worse than not enough, so testing your soil every two to three years is important. You can get instructions for doing a soil test from your Extension agent or agricultural advisor.
What Should I Consider When Choosing Blueberries Fertilizers?
Choosing a fertilizer can be confusing. There are three things I consider when choosing fertilizers.
The most obvious factor is price. Some fertilizers are cheaper than others. However, cheap fertilizers may use inferior sources of nutrients. Premium fertilizers may seem more expensive, but you typically have to use less to achieve the same results as with a cheaper fertilizer. In addition, premium fertilizers often use ingredients that are more bioavailable than cheaper fertilizers. While I can’t say the price isn’t a factor in my fertilizer purchases, I try to purchase only premium fertilizers for my plants.
The ratio of nitrogen, phosphorus, and potassium is the next factor I look at. The ideal blueberry fertilizer ratio is not as set as it is with lawns or some other plants. Depending on your soil analysis, ammonium sulfate (21-0-0). urea (46-0-0), or rhododendron food (9-15-12) are all appropriate. I pay more attention to the ratio of nutrients in the soil than to any other factor.
Some people want to use a liquid fertilizer, and some want to use granules. Liquids are used to water the bush and are easy to use when fertilizing blueberries in pots. They work quickly and you can see results in twenty-four to forty-eight hours. Liquids must be applied every one to two weeks. Granules typically have slow-release fertilizers and last from weeks to months. It takes one to two weeks to see results with slow-release fertilizers. Some granules also have fast-release fertilizer. I prefer granules that are at least half slow-release fertilizer for in-ground plants because I don’t have to administer them as often.
Top 5 Best Fertilizers For Blueberries
Blueberries need an acidic fertilizer. Do not use a fertilizer with nitrates or chlorates in it, as blueberries can’t use these forms of nutrients.
1. J R Peters Jacks Classic Acid Special Fertilizer – Best For Blueberries In Pots
J R Peters Jacks Classic No.1.5 17-6-6 Acid Special Fertilizer is my pick for the best fertilizer for blueberries being grown in pots.
The NPK ratio is 17-6-6 and the fertilizer also includes sulfur, copper, iron, boron, manganese, molybdenum, and zinc. The sulfur, zinc, and manganese boost the acidity of the soil to keep your blueberry plant happy. The iron keeps your leaves green by preventing iron chlorosis, which turns the leaves yellow. The fertilizer is a concentrated water-soluble formula, and the tub lasts a long time, making this fertilizer very cost-effective. It is not, however, organic and is toxic to children and pets, so keep it locked up where they can’t get it.
J.R. Peters is a famous company founded in 1947 by Bob Peters. The family-owned corporation is still owned by the original family. Bob Peters got his start by testing the soil in greenhouses and making custom recommendations for what nutrients the owner should use. He introduced Peter’s Professional Plant Food. In 1997, Jack’s Classic was developed as the finest in water-soluble fertilizer. Since then, the company has produced many specialty fertilizers such as J R Peters Jacks Classic No.1.5 17-6-6 Acid Special Fertilizer. The company headquarters and production facilities are located in Allentown, Pennsylvania. Dr. Cari is the third generation of the family to head the company. She works to continue to develop and offer innovative water-soluble fertilizers for professionals and homeowners.
To use this fertilizer, I mix one tablespoon of concentrate with a gallon of water and drench the soil around the plant. I repeat this every ten to fourteen days. This is great for outdoor containers like a half whiskey barrel planter.
To use this fertilizer for indoor potted blueberries, I mix ½ teaspoon of concentrate with a gallon of water and use it every time I water in place of water. Every three months or so, I flush the soil of the plant with lots of water to flush the salts out of the soil. Blueberries are sensitive to salt and can die when they build up.
I like this fertilizer because it is from a company famous for its fertilizer. My Dad used to have a tub of Peter’s Professional Plant Food in the laundry room he used for his potted plants. I also think it is very cost-effective because a tub lasts a long time. Because the formula is so concentrated, be sure not to use more than is on the label because it will burn the blueberry bush.
- Easy to mix
- Reputable company
- Has micronutrients in addition to NPK
- Can burn plants if mixed too strong
- Is toxic to children and pets
- Is not organic
2. Espoma Organic Holly-tone 4-3-4 – Best Organic Fertilizer For Blueberries
Espoma Organic Holly-tone 4-3-4 Natural & Organic Evergreen & Azalea Plant Food is my pick for the best organic fertilizer for blueberries.
The NPK ratio is 4-3-4 and it contains Espoma’s patented Bio-tone formula. It also contains sulfur, magnesium, and calcium. The Bio-tone contains several strains of Bacillus organisms to improve soil health. Humic acid, derived from Lenardite, is included. The humic acid and Bacillus microorganisms make the nutrients in the fertilizer more available and improve the soil structure. The sulfur helps acidify the fertilizer and is used to make amino acids. Magnesium is involved in photosynthesis. Calcium stimulates root and leaf growth. The product does not have iron, but this should not be a problem if the soil pH is in the right zone.
Espoma has been making organic fertilizers since 1929. Founded by Herbert G. Sanders, the headquarters are in Millville, NJ. In 1946, a fire burned the production area. Friends and employees started clearing the ground of debris, so Sanders rebuilt. In the late 1940s, Holly Society of America’s founding fathers Clarence Wolf and Daniel Fenton had close ties with Espoma. Sanders developed Holy-tone, the first commercially available acidifying fertilizer, with the requirements of hollies in mind. This was the start of research and development into specialty organic formulas for a wide variety of plants. Today, Espoma is the leading producer of organic fertilizers for the retail and lawn trade. It is still family owned and operated. Espoma is distributed all over the United States and Canada.
To use Espoma Organic Holly-tone 4-3-4 Natural & Organic Evergreen & Azalea Plant Food on in-ground blueberry bushes, spread one cup per foot of dripline diameter around the bush in a band, starting eighteen inches from the trunk. Double the rate if the diameter is larger than three feet. Water the area after spreading the fertilizer.
For container plants, sprinkle one teaspoon of fertilizer for every three inches of pot diameter around the outer edges of the pot. Water the plant after fertilizing it.
I like Espoma products and think this is an excellent product for blueberry bushes. However, Espoma products are premium products. They cost more because of the cost of organic ingredients, organic certification, and the cultures and humic acid in them. I think they are worth the extra cost, however. A bag will last all season and can be used on any acid-loving plant, not just blueberries. The bag reseals, but fertilizer gets stuck in the seal easily, so it doesn’t seal right all of the time. If the bag falls over, it will likely spill some fertilizer out.
- Premium ingredients
- Microorganism cultures
- Trusted manufacturer
- Can be used on any acid-loving plant
- The seal on the package doesn’t always seal well
3. Jobe’s Organics Soil Additive, Soil Acidifier – Best Acidifier Fertilizer For Blueberries
Jobe’s Organics, 09364, Soil Additive, Soil Acidifier is my pick for the best soil acidified.
The NPK ratio is 0-0-0. While this product is an additive that is used along with fertilizer, it can change the pH more than a fertilizer itself can. The acidifier is made of sulfur and gypsum. Elemental sulfur will acidify the soil and also promote green growth and is essential for the production of plant proteins. Gypsum is a stable form of sulfur that promotes green growth and aids in the production of enzymes and vitamins. Both products are organic and so is the product. It is safe for use around children and pets.
The Jobe’s Company was founded in 1969 and released its first tree spike then. In 1997, Easy Gardening bought Jobe’s brand. In 2007, Easy Gardener launched the Jobe’s Organics brand. In 2015, Centre Lane Partners bought Easy Gardener. In 2016, the name of the company changed from Easy Gardener to The Jobe’s Company. Now this company makes over 200 fertilizers and other gardening products that are distributed across North America. They are headquartered in Waco, Texas, and have additional manufacturing facilities in Kentucky.
It is essential that you do a soil pH test before you use this product. You do not want to drive the pH too far down. Before planting a blueberry bush, mix 1 ½ tablespoons per two-inch plant into the soil. Water the acidifier well. Before planting a blueberry bush in a container, use 1 ½ tablespoons per four-inch pot and mix well with the potting soil. For established plants in-ground or in containers, place 1 ½ cups of acidifier per foot of plant spread (width) in a band at the drip line. Water the product well to activate it.
I think Jobe’s Organics, 09364, Soil Additive, Soil Acidifier is a good product to use when you are setting up a big container, like half of a whiskey barrel, to plant a blueberry bush in. Since pH tends to creep up over time, using this product will help you keep the soil acidic enough to keep your blueberry bush happy. If your in-ground soil is close to neutral or alkaline, I think you will need to start using this product before you plant. Sulfur will bring the pH down, but it takes a while to do that. The recommendation for major pH changes is to start a year before you plant. You would be better off planting the blueberry in a large container, so you don’t have to worry about it. While this product is only moderately expensive, you do have the additional expense of buying a fertilizer to go with it.
- Safe for use around pets and children
- Organic formula
- Can move pH more than most fertilizers
- Must be paired with a fertilizer
4. Miracle-Gro Water Soluble Miracid Acid-Loving Plant Food – Best Inorganic Fertilizer for Blueberries
Miracle-Gro Water Soluble Miracid Acid-Loving Plant Food is my pick for the best inorganic fertilizer.
If using an organic product doesn’t matter to you, this is a good product to choose. If your blueberries are suffering from a nutrient deficiency, inorganic fertilizers are best because the nutrients go straight into the plant. The plants don’t have to wait for the microbes to digest the nutrients for them. In addition, inorganic fertilizers are much more powerful than most organic fertilizers. The NPK ratio is 30-10-10 as opposed to single-digit NPK ratios in organic products. The product also has boron, copper, manganese, zinc, iron, and molybdenum. The product is guaranteed not to burn your plants if used as directed.
Miracle-Gro is an old company. Founded by Horace Hagedorn and nurseryman Otto Stern in 1944, the first Miracle-Gro product was a fertilizer to strengthen plants for shipping. Hagedorn bought Stern out in the 1980s. In 1995, Miracle-Gro merged with Scotts to become Scotts Miracle-Gro, with Hagedorn’s son as the CEO of the new company. Scotts Miracle-Gro is sold throughout the United States and Canada. Scotts was founded in 1868 by Civil War veteran Orlando McLean Scott in Marysville, Ohio, to breed seed for farmers. After the turn of the century, he began selling to homeowners. Scotts still has a storefront in Marysville.
For outside plants, I mix Miracle-Gro Water Soluble Miracid Acid-Loving Plant Food by mixing 1 ½ tablespoons of fertilizer per 1 ½ gallons of water. Soak the soil around the plant every seven to fourteen days. For larger areas, you can use this with a hose-end Miracle-Gro Garden Feeder by filling the feeder with the fertilizer and spraying it at the base of each plant. Repeat every seven to fourteen days. Do not get the spray on the plants because it will burn them.
For inside plants, I mix ½ teaspoon of fertilizer per gallon of water. Water the plant with this solution every fourteen days instead of watering it.
I would use Miracle-Gro Water Soluble Miracid Acid-Loving Plant Food for indoor blueberry bushes and for ones in containers or in-ground outside. Miracle-Gro is a respected brand with a great deal of experience in inorganic fertilizers. I think the product is moderately priced and will last for a long time. However, the container is not very sturdy, and the package crumples easily and is hard to close, so you may have to put the fertilizer in a container, package and all, to keep it fresh.
- Greens up blueberry bush fast
- Respected company
- Not organic
- Bad packaging
- Must use every 7-14 days
5. Down to Earth All Natural Acid Mix Fertilizer 4-3-6 – Best Overall Fertilizer For Blueberries
Down to Earth All Natural Acid Mix Fertilizer 4-3-6 is my pick for the best overall fertilizer for blueberries.
It has an NPK ratio of 4-3-6 and also contains calcium, magnesium, and sulfur. In addition, there is humic acid derived from Leonardite, the best source for it. These are derived from cottonseed meal, fish bone meal, Langbeinite, rock phosphate, and kelp meal. Langbeinite is a crystalline mineral that is mined. It contains manganese, potassium, and sulfurs. Its natural chlorine content is below three percent, to minimize the chance of burning your plants. Most of the nitrogen in this fertilizer is slow release but some is released fast. This means you will see a quick result that lasts for quite a while.
Down to Earth was founded in 1977 by Jack Bates because he could not find many organic formulations of gardening products for people who wanted them. He mixed his early fertilizers by rolling 55-gallon drums across the parking lot. Today, Down to Earth has a complete line of natural and organic fertilizers, soil amendments, composts, and potting media that work with the microorganisms in the soil to provide what plants need to grow strong. They use the best quality ingredients to provide premium products that work with nature. Their products are used by homeowners, commercial growers, nurseries, and garden centers who want organic products. The package is biodegradable. This is an organic product.
For new gardens, use 2.5-5.0 pounds of Down to Earth All Natural Acid Mix Fertilizer 4-3-6 per 100 linear feet and mix it into the top three inches of soil. Alternatively, you can mix ½ cup of fertilizer in the backfill dirt and use that to fill the hole when planting your blueberry bush. Do not put fertilizer in the hole under the roots, as this will burn them. For existing plants, mix one cup of fertilizer into the top three inches of soil around each blueberry bush in the spring when the plant leaves out. Water the area well. Repeat when the plant blooms. In the fall, mix ½ cup of fertilizer with the top three inches of soil around the blueberry bush and water well. The fall feeding helps the plant survive the winter.
I think this fertilizer is a good premium fertilizer. It is a little pricey, but in this case, you get what you pay for. Down to Earth is a good, reputable company that makes its products in the United States. The ingredients are good for the organisms in the soil and nurture them so they can nurture your plants.
- Biodegradable packaging
- Organic fertilizer
- May have an unpleasant smell
When Do I Fertilize Blueberries?
When you fertilize your blueberry bush is as important as how you fertilize it.
Time of Day
Always fertilize your blueberries in the morning.
It is best to fertilize between six and ten in the morning. If you are using a liquid fertilizer, that allows any that gets on the stem and leaves to dry before nightfall, reducing diseases.
If you are using a granular fertilizer, you will almost certainly have to water the fertilizer in. You should water between six and ten in the morning for the same reason you use liquid fertilizer then.
Stages of Growth
Blueberries are typically planted in October in the Southern United States. They are planted in January or February in the North. The first spring starts the first year of the blueberries’ life, no matter how big it is.
The first spring, start fertilizing when the first growth starts on the plant. Divide the amount of fertilizer into thirds and fertilize a third once growth starts, a third a month later, and a third in another month.
In the second year, increase the fertilizer but fertilize at the same times of the year.
In the third year and following, increase the fertilizer again but fertilize at the same times of the year.
Time of Year
The time of year you fertilize depends on the part of the country you are in. Here are some representative states and the time of year to fertilize in each.
Apply one-third of the recommended granular fertilizer in late April, late May, and late June in the Willamette Valley and southwestern Oregon; apply a month early in other parts of Oregon. For liquids, apply weekly from late April to late July.
The first spring after planting, when new growth begins (late March to early April), apply the first dose of fertilizer. Repeat this dose in May and July. The second spring, fertilize in March and July. From the third season on, fertilize when the buds break open and just after the harvest is finished.
For the first year after planting, wait until the first leaves have reached full size to fertilize. After that, fertilize every six weeks until mid-August on the Coastal Plain and mid-July in the mountains. For the second year, start fertilizing when the first growth starts and continue as you did the first year. For the third year and after, apply fertilizer when growth begins in the spring. You can repeat the fertilizer every six weeks as in the previous years.
How Do I Fertilize Blueberries?
Generally, you fertilize blueberries in early spring and then a few times after that. How many times depends on your climate and soil.
You spread the granular fertilizer in a band around the blueberry bush and start about a foot from the bush. Water the area well after spreading the fertilizer to activate it.
Liquids are poured in a band around the blueberry bush until the soil is wet and the needed amount of fertilizer is applied. The exact amounts of fertilizer depend on the brand and are listed on the package.
Blueberries need lots of fertilizer but are sensitive to it, so the amount they need is generally divided into two or three parts. For examples of fertilizer amounts, see the instructions for each brand I recommend.
Signs You Are Over-Fertilizing Your Blueberries
If you put out fertilizer and a few days later, your leaves turn brown, you have put too much fertilizer out.
Flush the blueberry bush with lots of water to dilute the remaining fertilizer.
Overdoing the nitrogen results in lots of foliage and few or no blooms and fruit.
Too much phosphorus reduces the plant’s ability to take up micronutrients like iron and zinc. This can cause iron chlorosis, which turns the plant’s leaves yellow.
Excess potassium can reduce the plant’s ability to take up magnesium and calcium. Excess boron is fatal to plants.
Homemade Fertilizer for Blueberries
You can easily make a fertilizer for blueberries using soil test recommendations and several easy-to-obtain items. Be careful to use premium quality ingredients.
For the nitrogen, choose from these ingredients:
- Four to five cups of coffee grounds (also adds acidity)
- Finely ground eggshells (crushed eggshells will not work, they must be finely ground)
- Composed chicken manure (never use uncomposted manure on plants because it carries disease organisms that will make you sick.)
- Fish meal
- Soybean meal
- Blood meal
For the phosphorus and potassium, choose from these ingredients:
- Bone meal
- Powdered seaweed
If you prefer to use a liquid fertilizer for your blueberry bushes, you can use liquid kelp or fish emulsion.
If your soil is low in magnesium, broadcast ¼ cup of Epsom salts in a band around your blueberry bush, starting at least ten inches from the trunk. Be careful not to apply this too often. Blueberry bushes are sensitive to the accumulation of salts in the soil.
Caring For Your Blueberries Throughout Their Lifecycle
Blueberry bushes need more than just fertilizer to grow well and produce lots of blueberries. Here are some tips to maximize your blueberry crop.
- Blueberry bushes can produce blueberries for fifty years, so choose where you plant them carefully.
- Rabbiteye and southern highbush blueberries are grown in the Southern United States.
- Half-high blueberries are grown in extremely cold conditions, such as Canada experiences.
- High blueberries are grown in the Northern United States and are the most prolific of the blueberries.
- Putting three inches of mulch around your blueberries helps keep them free of weeds.
- Mulch also stabilizes the soil temperature and soil moisture.
- Pine bark, chips, or sawdust is better than hardwood mulch because it is acidic.
- Each year, add one inch of mulch to the mulch in the spring.
- You can put fertilizer over or under the mulch.
- Soak bare-root blueberry plants for half an hour before planting.
- Blueberries like lots of organic material in the soil around them. Before planting your blueberry bushes, mix three inches of compost into the top six to twelve inches of soil.
- Blueberry bushes require well-drained soil. Do not plant them where water accumulates after a rain, or the roots will rot.
- When you water your blueberry bushes, wet at least fifty percent of the soil under the dripline of the bush.
- Water no more than every two days to avoid keeping the soil too wet and rotting the roots.
- The water table should be no closer than 14 inches to the surface of the soil where your blueberry bush is planted.
- Do not get the foliage or stems wet when watering a blueberry bush. Wet stems and leaves can lead to diseases.
- For the best yield, plant your blueberry bush in an area where it will get at least six hours of sunlight a day.
- Planting blueberry bushes in the fall in warmer climates allows the bushes to become established before winter.
- Space highbush and half-high bush varieties four to five feet apart in rows eight to ten feet apart.
- Plant rabbiteye and lowbush varieties six feet apart and in rows ten to twelve feet apart.
- Keep weeds out of the blueberry patch as they compete with the blueberry bushes for water, nutrients, and sunlight.
- Blueberry roots are shallow, so hoe no more than one inch deep when weeding.
- Prune 2/3 off the top of bare-root plants when planting.
- Prune 1/2 off the top of potted plants when planting.
- Remove all flower buds the first two years after blueberry bushes are planted.
- In the third year, let a small number of flower buds stay on the bush.
- In year four and going forward, prune off about fifty percent of the blooms to avoid breaking branches and to get larger berries.
- In the winter, remove canes that are weak, damaged, and diseased.
- The first two years after planting, this is all the pruning that is necessary.
- After year three, prune excessively tall shoots to force the plant to branch more.
- After the fourth year, each bush should produce about ten pounds of fruit. Rabbiteye bushes occasionally produce up to twenty-five pounds of fruit.
- Pick high and half bush varieties every five to seven days.
- Pick rabbiteye and low bush varieties every ten days.
- Birds will clean a bush of berries very quickly. Use bird netting to prevent them from stealing your crop.
- When choosing a potting soil for your container blueberry bushes, choose one with a large portion of well-aged, fine bark (50% to 80%), peat moss (10% to 40%), and perlite or pumice (10%).
- Wet the potting soil by soaking it overnight before planting your blueberry bush in it.
- If you are planting a pot-bound blueberry bush, rub the outer roots with a gloved hand to rough the roots up and stimulate growth.
- Animal and mushroom-based compost has a lot of salt in it and can damage your blueberry bush.
- Blueberry bushes need 1.5-3 inches of water a week, depending on soil type and temperature.
- Irrigate frequently enough that the soil doesn’t completely dry out between waterings.
- If you use fresh and not composted sawdust as a mulch, you will need to add more nitrogen to make up for the nitrogen microorganisms use to break down the sawdust.
- Do not wash the fruit before storage.
- Store fruit in the refrigerator for two to six weeks.
- Place the berries in a container and cover them with wax paper, not a tight-fitting lid.
- You can freeze blueberries for six months to a year before they lose flavor and nutrients.
- When it is over 95 degrees F, blueberries in the late green and blue stage can get sunburned. se shade cloth to protect the blueberries from the sun to prevent sunburn.
Blueberry bushes are acid-loving plants that need to be fertilized to produce lots of blueberries. y pick for the best overall fertilizer is Down to Earth All Natural Acid Mix Fertilizer 4-3-6. his is a premium fertilizer made by a well-respected company. y pick for the best inorganic fertilizer is Miracle-Gro Water Soluble Miracid Acid-Loving Plant Food. his fertilizer is good for quickly dealing with a nutritional deficiency. y pick for the best organic fertilizer is Espoma Organic Holly-tone 4-3-4 Natural & Organic Evergreen & Azalea Plant Food. his fertilizer was one of the first specialty fertilizers for acid-loving plants. y pick for the best acidifier fertilizer is Jobe’s Organics, 09364, Soil Additive, Soil Acidifier. While not a fertilizer, when used in conjunction with a fertilizer, this product can adjust the pH more than just a fertilizer can. Finally, my pick for the best fertilizer for blueberry bushes in containers is J R Peters Jacks Classic No.1.5 17-6-6 Acid Special Fertilizer. Peters is famous for its plant foods, and this is a good water-soluble food to use when watering your container blueberry bush.