How and When to Fertilize Blueberries to Boost Your Harvest

2024-02-23
How and When to Fertilize Blueberries to Boost Your Harvest

For a bumper crop of luscious fruit and healthy plants, you need to know when to fertilize blueberries as well as the best ways to provide your plants plenty of nutrients. Yep, you have to feed them, and do so at the optimal times to encourage fruit production. This guide explains everything you need to know about fertilizing blueberry plants so you can harvest buckets of delicious berries.

Start with a Soil Test

Before you add fertilizer to blueberries or throw down any amendments in your garden, test the soil. You need to know the condition of the soil to grow any plants successfully. Garden soil can accumulate salts from overuse of fertilizers over time or become depleted of vital nutrients. A soil test tells you exactly which nutrients and other amendments you need to add to the soil. Plus you'll be able to tell whether the pH needs to be adjusted for acid-loving blueberry plants.

You can get DIY soil testing kits online or have your soil tested by your local cooperative extension office. Blueberries grow best in well-drained, acidic soil with a pH of 4.3 to 5.3 and fortified with organic matter. Once you know your soil pH, you can adjust it as needed.

Best Fertilizer for Blueberries

Most fruit crops need annual applications of nitrogen fertilizer to support the growth of roots, leaves, and fruit. The best fertilizer for blueberries gets its nitrogen from ammonium and not nitrate. Blueberries are sensitive to nitrate, and their roots can be damaged by it. Use a fertilizer that gets its nitrogen from urea, sulfur-coated urea, ammonium sulfate, or cottonseed meal.

Try a 7-7-7 or 4-3-4 fertilizer formulated for acid-loving plants. Any fertilizer sold for azaleas or rhododendrons will work well for blueberries. Cottonseed meal is also a good fertilizer for blueberry plants.

Fertilizer alone won’t give you a bumper crop of blueberries, though. You need to feed the soil, too. Add organic material, such as aged manure or compost, to your garden soil to give blueberry plants the nutrients they need to thrive. Rely on the soil test to tell you what amendments to add to your soil to keep blueberries happy and healthy.

When to Fertilize Blueberries

Time the feeding of blueberry plants around their cycle of plant and berry growth and feed your blueberry plant three times a year:

  • Early Spring: Apply fertilizer as new plant growth begins and before the buds open. This is usually March or April but varies according to your growing zone.
  • Late Spring/Early Summer: Apply a second round of fertilizer six weeks later to support the growing berries and leaves.
  • After Harvest: Apply a third dose of fertilizer after you pick the berries in June or July to restore strength to the blueberry plant. That plant put its all into producing a berry crop and needs a nutritional boost.

How Much Fertilizer to Give Blueberries

Too much nitrogen fertilizer can cause a blueberry plant to grow lots of branches at the expense of berry production. The amount of fertilizer you apply depends on the maturity of the blueberry plant. The older the plant is, the more fertilizer you need to apply each year to support fruit growth.

  • For first- and second-year blueberry plants, apply half the fertilizer recommended on the label for mature plants.
  • For third-year blueberry plants, apply ¾ the amount of fertilizer recommended on the label for mature plants.
  • For four-year and older blueberry plants, apply the full amount of fertilizer recommended on the label. At four years, a blueberry plant is mature and can handle a full dose of fertilizer.

How to Fertilize Blueberries

Blueberry plants take up nutrients through their root system, so apply fertilizer to the soil at the base of the plant as a top dressing. Don’t rake or cultivate the soil around the base of the blueberry plant to work in granulated fertilizer; just water it in. Blueberry plants have shallow root systems that can be damaged if you dig in the soil.

Mulch Your Blueberry Plants

Blueberry plants grow faster and produce more berries if you put a 2- to 3-inch-deep layer of organic mulch around the base of the plants. A layer of pine bark, pine straw, compost, or wood chips helps blueberry plants retain moisture and suppress weeds that take nutrients away from the blueberries. The mulch also feeds the soil by adding organic matter as it breaks down. You’ll see steady growth and consistently high yields of blueberries if you mulch the plants.

Don’t use mulch with a high pH, like mushroom compost. Pine bark or pine straw is the best choice because it is acidic and lowers the soil’s pH as it decomposes. Blueberries prefer acidic soil.

Frequently Asked Questions

  • Why are my blueberry plant leaves turning yellow or pale green?

    Yellow leaves might indicate your plant has chlorosis; it isn’t getting enough sun, water, and nutrients to make the chlorophyll it needs to thrive. Yellow leaves could also mean the plant has a nutritional problem. You might be able to correct the condition by adding organic material to the soil, fertilizing the blueberry plant, or adjusting the soil pH.

  • Which fertilizer makes blueberries sweet?

    The three factors governing blueberry sweetness are sunlight, weather, and soil nutrition. Get any of those wrong, and blueberries will be less sweet. Make your soil pH correct and feed a balanced fertilizer formulated for berries that is high in potassium (the K in the N-P-K ratio.)

Related Article

How to Plant and Grow Rose of Jericho

How to Plant and Grow Rose of Jericho

Rose of Jericho is a unique houseplant that can survive with minimal water, making it a great option for travelers and forgetful gardeners.
21 Adorably Petite Plants for Fairy Gardens

21 Adorably Petite Plants for Fairy Gardens

Color is always nice, but scale is everything when choosing miniature garden plants. Peruse our favorite picks for fairy gardens and terrariums.
13 Colorful Nectar Plants for Pollinators

13 Colorful Nectar Plants for Pollinators

Create a gorgeous, pollinator-friendly garden by including these nectar-rich plants.
Is Coleus a Perennial or Annual? Here's How to Grow It Both Ways

Is Coleus a Perennial or Annual? Here's How to Grow It Both Ways

Is coleus a perennial that comes back every year? That depends on where you live and how you care for it. Use these tips to enjoy coleus as a colorful perennial or annual plant.
How to Plant and Grow Ranunculus

How to Plant and Grow Ranunculus

Ranunculus are favorite flowers for weddings, arrangements, and gardens. Here's how to plant and grow ranunculus.
How to Plant and Grow Glossy Abelia

How to Plant and Grow Glossy Abelia

This guide on how to grow glossy abelia includes essential planting and care tips such watering, fertilizing, and pruning needs. You'll also find popular types of abelia to grow and pretty companion plants for this flowering shrub.
Hydrangeas Not Blooming? 7 Reasons Why and How to Fix the Problem

Hydrangeas Not Blooming? 7 Reasons Why and How to Fix the Problem

Hydrangeas not blooming can be a frustrating problem for gardeners. These straightforward tips will promote tons of long-lasting flowers.
10 Best Sweet Potato Companion Plants for Larger Harvests

10 Best Sweet Potato Companion Plants for Larger Harvests

Mix and match these sweet potato companion plants in your vegetable beds for pest-free crops and easier gardening.
How to Harvest Mint, Dry Mint, and Store Mint

How to Harvest Mint, Dry Mint, and Store Mint

Learn how to harvest mint to keep plants more manageable and gather fresh mint leaves for cooking, drying, and storing!
How and When to Harvest Radishes at Their Peak

How and When to Harvest Radishes at Their Peak

These easy-to-follow tips will help you figure out how and when to harvest radishes for the best flavor and size. Plus, get troubleshooting advice if your radish roots aren't developing properly.
How and When to Start Tomato Seeds Indoors

How and When to Start Tomato Seeds Indoors

Find out exactly how and when to start tomato seeds indoors so they'll be ready to transplant into your garden in spring.
Tillers vs. Cultivators: How to Choose the Right One for Your Gardening Tasks

Tillers vs. Cultivators: How to Choose the Right One for Your Gardening Tasks

Learn the differences between tillers and cultivators and the tasks they're best suited for.
Here’s What Not to Put in Compost to Avoid a Contaminated Bin

Here’s What Not to Put in Compost to Avoid a Contaminated Bin

Composting is a simple way to turn your kitchen and yard waste into food for your garden. But some of these items should never be in compost.
Easy Lawn Repair for Patchy Grass Using Seed or Sod

Easy Lawn Repair for Patchy Grass Using Seed or Sod

With a bit of grass seed or sod, lawn repair is easy, and you’ll soon have a lush green carpet again.
What Are the Tiny White Bugs on Your Plants? 4 Common Pests They Could Be

What Are the Tiny White Bugs on Your Plants? 4 Common Pests They Could Be

Tiny white bugs on plants in your home or outdoors can be a big problem. Learn how to identify and get rid of them with this guide.
How to Spot 5 Common Plant Diseases and Keep Your Garden Healthy

How to Spot 5 Common Plant Diseases and Keep Your Garden Healthy

Protect your plants from the most common diseases. Learn to recognize the symptoms and how to prevent these diseases in the first place.
How to Landscape with Rocks and Stones in Your Yard

How to Landscape with Rocks and Stones in Your Yard

Decorative rocks and stones add another element of nature to your yard, whether you grow hydrangeas, tulips, or cacti.
Landscape Planning Tips From Start to Finish for a Perfect Yard

Landscape Planning Tips From Start to Finish for a Perfect Yard

Even if you're a beginner, these simple landscape planning tips will take the mystery out of designing your yard's ideal layout.
10 Native Alternatives to Invasive Plants Growing in Your Garden

10 Native Alternatives to Invasive Plants Growing in Your Garden

Use native plants in your garden instead of popular invasive landscape plants: See a list of common invasive plants, plus native alternatives to plant instead.
Your Seasonal Lawn-Care Schedule for the Midwest

Your Seasonal Lawn-Care Schedule for the Midwest

Use our lawn-care schedule to help you maintain a beautiful yard all year long. You'll learn exactly when to mow, aerate, fertilize, and overseed.