If your blueberry bushes are not growing well or producing many berries, fertilizer and soil pH are often the reason.
Blueberries need acidic soil and the right nutrients to thrive. Once you understand when to fertilize and what products to use, blueberry plants are usually easy to grow and highly productive.
Looking for more ideas? See all my blueberry recipes, drinks, and growing tips here.
Quick Answer
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The best time to fertilize blueberry bushes is:
- Early spring when new growth begins
- Again every 6–8 weeks during the growing season
- Stop fertilizing after harvest or by late summer
Use fertilizer made for acid-loving plants such as blueberries, azaleas, or rhododendrons.
Before adding fertilizer or soil amendments, learn how to test soil pH at home so you know exactly what your blueberry bushes need.
Why Blueberries Need Special Fertilizer
Blueberries are different from many garden plants because they need:
- Acidic soil
- Steady nitrogen
- Good organic matter
- Consistent moisture
If soil pH is too high, plants cannot absorb nutrients properly.
That often leads to:
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- Yellow leaves
- Red leaves
- Poor growth
- Few berries
Related: Blueberry Leaves Turning Red: Causes and Solutions
Best Soil pH for Blueberries
Blueberries grow best in rich, well-drained acidic soil—see my guide to the best soil for blueberries for simple ways to improve planting success.
Blueberries grow best when soil pH is between:
4.5 and 5.5
Before adding fertilizer, test your soil.
Related: Optimizing Soil pH for Blueberries
If pH is too high, lowering the pH may help more than fertilizer alone.
Not sure where to start? See my guide to the best soil pH test kits for gardeners to choose an easy option for checking blueberry soil.
Best Time to Fertilize Blueberries
Newly Planted Bushes
Wait about 4 weeks after planting before fertilizing.
This gives roots time to settle.
Established Plants
Fertilize:
- Early spring when buds swell or leaves emerge
- Every 6–8 weeks through early summer if needed
Stop feeding after fruiting season ends.
Late fertilizing can encourage tender new growth before winter.
Best Fertilizer for Blueberry Bushes
Choose fertilizers labeled for:
- Blueberries
- Azaleas
- Rhododendrons
- Acid-loving plants
Look for slow-release formulas.
These usually provide nitrogen gradually, which blueberries prefer.
Are Coffee Grounds Good for Blueberries?
Coffee grounds can help add organic matter and mild acidity.
Use them lightly:
- Apply dried grounds around plants
- Work gently into topsoil or mulch
- Use monthly in small amounts
Do not overdo it.
Too many coffee grounds can compact soil or alter pH too much.
Always retest soil periodically.
Can You Use Vinegar for Blueberries?
Some gardeners use diluted vinegar water to temporarily lower soil pH.
Mix:
- 1 tablespoon white vinegar
- 1 gallon water
Use occasionally, then retest soil.
Important Note
Vinegar is a short-term fix, not the best long-term solution.
For lasting results, sulfur or soil amendments are usually better.
Watering Matters Too
Fertilizer works best when blueberry plants are watered properly.
Blueberries like:
- Even moisture
- Mulch around roots
- Well-drained soil
Dry plants struggle to use nutrients.
Signs Your Blueberries Need Help
Watch for:
- Pale or yellow leaves
- Red leaves during growing season
- Weak new growth
- Small berries
- Low harvests
Easy Blueberry Feeding Plan
Spring
- Test soil pH
- Apply acid-loving fertilizer
- Mulch plants
Early Summer
- Light second feeding if needed
- Keep watered
Late Summer / Fall
- Stop fertilizing
- Focus on watering and mulch
FAQs
Can I use Miracle-Gro on blueberries?
Only if it is formulated for acid-loving plants.
How often should I fertilize blueberries?
Usually once in spring, with a second light feeding later if needed.
Can too much fertilizer hurt blueberries?
Yes. Too much fertilizer can burn roots and reduce fruiting.
More Blueberry Growing Tips
You may also enjoy:
- How to Grow Blueberries in Pots
- Blueberry Leaves Turning Red
- How Many Blueberry Bushes Should I Plant?
- Best Soil for Blueberries in Containers
Explore all my blueberry recipes, growing tips, and preserving ideas here.
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Aluminum sulfate or 32% is the fastest way to drop ur ph of soil and if it gets to low add crushed lime to raise it back up
Loved your blueberry article I bought some last year and they are slowly growing. I was wondering if you had any advice on an heirloom lilac bush?
I have one that’s over a hundred years old and looking pretty scruffy. How can I improve this poor thing?
This is so interesting! I never would have thought to use vinegar, I usually just use an Espoma soil acidifier! I’m going to try this, this year! Great info!