How to Choose the Best Fertilizer for Blueberries

Blueberries are some of the easiest shrubs to care for since they don’t require much space, have a simple routine, attract few pests, and bear fruit for many years.

However, growing blueberries still comes with challenges, especially if the soil doesn’t provide the nutrients they need.

Applying the right amount and type of shrub fertilization offers one way to provide blueberry plants with the right nutrients.

Whether you’re a newbie at planting or a seasoned gardener, here’s a quick guide to choosing the best fertilizer for blueberries, plus tips to help them grow healthy

How to Choose a Fertilizer for Blueberry Plants

Before applying fertilizer to your blueberry plant, here’s how to know what fertilizer to get.

Understand What Blueberries Need to Grow

Blueberry plants need proper nutrition and conditions to grow and produce healthy fruits.

Most fruit crops require essential nutrients like nitrogen, phosphorus, and potassium. These are mostly available in the soil, but if the soil lacks them, you must add fertilizer to improve the plant’s condition.

Blueberries are acid-loving plants, requiring you to maintain soil acidity. Blueberries need a soil pH level between 4.5 and 5.5 for optimal growth.

A soil pH under or over the blueberry’s ideal condition will prevent the plant from absorbing nutrients effectively, resulting in poor growth and fruit production.

Besides these, ideal conditions for growing blueberries include:

• Having sunlight for at least 8 hours daily
• Being placed in well-drained soil
• Being planted in organic matter, like peat moss, manure, and composted leaves

Take note of these necessities before putting fertilizer, so you can grow your blueberry plants well.

Conduct a Soil Test

A soil test analyzes the soil’s physical, chemical, and biological characteristics to let you know the nutrients it contains and lacks.

Since blueberries are acid-loving plants, testing can reveal your ground’s soil pH and give you an idea of what fertilizer to get.

For example, if your soil pH is high, use fertilizers high in elemental sulfur and iron to lower the pH level and maintain an acidic soil.

Ultimately, soil testing provides information on your plant’s needs before you fertilize blueberries.

Check the Condition of Your Blueberry Plants

Besides testing, you can also observe the physical condition of your blueberry plants. Nutrient deficiencies can primarily show as yellow or pale green leaves.

Despite having the right soil pH, yellowing leaves can indicate a lack of nitrogen, while poor flower or fruit production may mean low potassium or phosphorus.

Other common signs of nutrient deficiencies include:

• Reddish Leaves: Suggests lack of phosphorus
• Small Leaves: May indicate nitrogen deficiency
• Interveinal Chlorosis: When the leaves turn yellow between the veins, it indicates iron or magnesium deficiency.

These signs can help you know what nutrients to give before fertilizing blueberries.

Choose a Type of Blueberry Fertilizer

You can find three different types of fertilizers, depending on the purpose. These purposes include:

• Lower the soil’s pH to achieve the target pH level
• Add nutrients to the soil without changing the soil pH
• Acidify the soil and add nutrients

Choose the type of blueberry fertilizer based on what your plant needs.

Meanwhile, these fertilizers can come in two forms:

• Water-Soluble Fertilizer: This fertilizer dissolves in water easily and provides blueberry plants with nutrients quickly. However, this fast-release fertilizer needs to be applied frequently.
• Granulated Fertilizer: It’s a slow-release fertilizer in the form of pellets. Since they provide nutrients over time, you don’t need to apply them frequently.

When choosing a type and form of fertilizer, always consider what your blueberry plant needs.

Also, follow instructions in the packaging carefully to avoid putting too much or too little.

Organic Options to Fertilize Blueberries

Using natural fertilizers maintains soil health, provides a steady release of nutrients, and increases water retention.

Besides peat moss and compost, here are other organic matter options to use as fertilizer for your blueberry bushes.

Pine Bark

Pine bark is made from the shredded bark of pine trees, and it has a pH level between 4.0 and 5.0, making it an ideal blueberry fertilizer.

This organic matter lasts longer than other natural mulches and targets the root zone, enabling long-term plant growth and fruit production.

Creating raised pine bark beds can provide plants with drainage and aeration, which help minimize root diseases.

However, note that pine bark doesn’t hold water and nutrients, like nitrogen, well.

If you want to use pine bark for your plant bed, apply nitrogen to the bark three months before planting the blueberry bushes.

Cottonseed Meal

Cottonseed meal contains crushed left-over cottonseed from oil extraction.

It includes around 6 percent nitrogen, 2 percent phosphorus, and 1 percent potassium, providing a good amount of nitrogen while lowering the soil pH.

Note that some cottonseed meal products may contain residue of chemicals from the cotton plant. Read the package label first before buying or fertilizing blueberries.

Coffee Grounds

Using coffee grounds on your blueberry bushes is a simple but effective fertilizing option.

Coffee grounds contain essential nutrients, like nitrogen, potassium, and carbon, that promote growth and delicious yields.

Coffee grounds are also acidic which helps you increase or balance out the soil pH level. To use this, sprinkle 4 to 5 cups of ground coffee around the blueberry bush and lightly rake the topsoil.

Blood Meal

A blood meal is a dense organic nitrogen source for plants containing dried slaughterhouse waste.

After applying this fertilizer, the nitrogen will remain in the soil for 2 to 6 weeks.

Read the blood meal package’s instructions carefully, and avoid using too much fertilizer on your blueberry bush, as it can burn your plant.

You can apply the blood meal during spring, summer, or planting time.

Feather Meal

Feather meal contains grounded feathers from poultry animals. This powder-like fertilizer is high in nitrogen and often mixed in other fertilizers and animal food.

Overall, it’s a great slow-release fertilizer, providing blueberries a steady supply of nitrogen over time.

What to Look for in Chemical Blueberry Fertilizers

If you prefer to use chemical fertilizer, get one containing the right amount of nutrients your blueberry bushes need.

It’s highly recommended to use a slow-release nitrogen source to prevent leaching.

You can try formulas for acid-loving plants, such as a 4-3-4 or 7-7-7 (percentage of nitrogen, phosphorus, and potassium) fertilizer. Fertilizers for rhododendrons and azaleas also suit blueberries.

Note that blueberries require fertilizers using the ammonium form of nitrogen, such as ammonium sulfate, urea, and sulfur-coated urea.

Avoid buying fertilizer in the nitrate form since they’re toxic for blueberry plants.

Ultimately, choose a chemical fertilizer to help maintain an acidic soil condition for your blueberries.

How to Apply Fertilizer to Blueberry Plants

Here’s a simple four-step guide to fertilizing blueberries.

Rake the Soil Shallowly

Start by raking the soil gently around the blueberry bush.

Blueberries have shallow root systems, so be careful not to rake deeply and carelessly. Just loosen the soil to mix the fertilizer better.

Sprinkle the Blueberry Fertilizer

Spread the blueberry fertilizer around its drip line and one foot outward the bush.

If you’re using granules, distribute it evenly with your hands or a cup.

Since blueberry roots are shallow and fibrous, avoid lumping too many granules in one area to avoid burning the roots.

Follow the fertilizer packaging’s instructions to know how much fertilizer to apply.

Water the Soil

After spreading the fertilizer, you can water the soil.

However, don’t overwater to prevent the nutrients from leaching. Just pour enough to moisten the soil and dissolve the fertilizer.

You can also check your fertilizer packaging to see the recommended amount of water if any.

Place Mulch

Topping the soil with mulch is optional but highly recommended.

Mulch, like shredded leaves and wood chips, stabilizes the soil’s temperature, retains moisture, prevents soil erosion, and kills weeds naturally.

If you’re using granular fertilizer, put the mulch after spreading the fertilizer to help it penetrate the soil and roots.

Otherwise, you may place mulch before or after pouring liquid fertilizer.

When Is the Best Time to Fertilize Blueberries?

Putting fertilizer depends on your blueberry plant’s growth. Start applying fertilizer one year after planting. Apply fertilizer three separate times:

• First Application: During spring
• Second Application: 6 weeks after first application
• Third Application: After harvesting

For third-year blueberry plants, increase the frequency of application by 0.75. Give the full rate to older plants.

Best Practices to Grow Blueberry Plants

Follow these tips to care for your blueberries and yield more fruits.

• Avoid Putting Too Much Nitrogen: Excess nitrogen can kill your blueberry plants. Be careful of how much fertilizer you apply, and follow the appropriate amount of nitrogen depending on your plant’s growth stage and soil test results.
• Plant Different Blueberry Varieties: Growing two or more varieties increases your yield. Most blueberries can’t pollinate themselves, so planting more varieties helps pollinate each variety and produce more fruits.
• Retest Your Plant’s Soil pH: Test the soil every 4 to 5 years to know the current pH level and see if you need to change or adjust your blueberry fertilizer.
• Avoid Putting Fertilizer on the Blueberry Bush: When sprinkling fertilizer, avoid putting fertilizer on or near the leaves and stem since it will damage the plant. Brush it off immediately if a granular fertilizer comes in contact with the plant.

Grow Healthy Plants with the Right Fertilizer Program

If you don’t have the time or means to fertilize and care for your blueberry plants year-round, consider seeking the help of a professional.

A lawn care service like SunCo offers fertilization programs that cater to your blueberry, tree, garden, or lawn needs.

Besides fertilization, you can also get services for overall plant health care and weed control, among many others.

If you’re interested in SunCo’s lawn care service and programs, get in touch with SunCo’s Outdoor Specialists today!