Why are my blueberry leaves turning yellow?
Yellow between green veins means the soil is not acid enough.
Blueberries need pH 4.5 to 5.5. Above about 5.3 they cannot take up iron, and the youngest leaves yellow between dark green veins. In the ground, sulphur brings the pH back down. Red and yellow leaves in autumn are normal: blueberries are deciduous.
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- Young leaves yellow, veins green: the pH is too high. Sulphur.
- Old leaves yellow all over: hungry. An ericaceous feed in spring.
- Autumn red and yellow: normal before leaf fall.
Which yellow is it?
| What you see | Likely cause | What to do |
|---|---|---|
| Newest leaves yellow, veins stay green | pH above about 5.3, iron locked up | In the ground: sulphur, up to 85 g a bush a year, at most 25 g/m² a dose. In a pot: fresh ericaceous compost |
| Older leaves pale yellow all over | Short of nitrogen | Ericaceous feed in spring; blueberries prefer ammonium nitrogen |
| Red and yellow in autumn | Normal autumn colour | Nothing |
| Yellow, wilting, wet compost | Waterlogging | Clear drainage; raise the pot |
| Yellow and crisp in summer | Drought: shallow roots | Water with rainwater; mulch with bark |
Target pH and chlorosis threshold: Cornell; Oregon State. Sulphur rates on our product page: up to 85 g a bush a year (Oregon State; Cornell), never more than 25 g/m² a dose over the root area (University of Georgia). Higher rates can burn or kill the plants (Cornell).
Work out your exact amount. Enter your area, your test reading and your soil type, and the calculator gives the dose, the timing and the bags to buy.
Fixing high pH
- Test first. Know the number before you add anything.
- In the ground, sulphur. Up to 85 g a bush a year and never more than 25 g/m² a dose, once in early autumn or split between early spring and late autumn. Scatter over the root area and water in.
- In a pot, repot. Fresh ericaceous compost every two to three years. No sulphur in pots (RHS).
- Rainwater only. Tap water is the commonest reason potted blueberries yellow.
Common questions
Will yellow blueberry leaves turn green again?
Mildly yellow leaves can regreen once iron is available. New growth comes through green once the pH is right.
Why are my potted blueberry leaves turning yellow?
Usually tap water or tired compost has raised the pH. Repot in ericaceous compost and switch to rainwater.
Can I use chelated iron on blueberries?
Yes, as a quick fix: it regreens leaves in weeks. It does not lower the pH, so pair it with sulphur in the ground.
How long does sulphur take to work on blueberries?
It starts within weeks in warm soil. Retest after three to six months.
More: Sulphur Soil Acidifier · soil pH calculator · soil for blueberries · rhododendron leaves turning yellow · azalea leaves turning yellow · iron sulphate vs sulphur · how to make soil more acidic
Fix the soil, and the green comes back
90% elemental sulphur in pastilles that spread without dust and break apart when wet. Up to 85 g a bush a year, no more than 25 g/m² a dose.
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Free UK delivery over £40. Buy now goes straight to checkout.
Free UK delivery over £40. Dispatched in 1 to 2 working days. Packed and posted from Stockport.