Berry Fertilizer for Raspberries & Blackberries

When your berry plants may benefit from feeding

When container-grown berries start active spring growth and their potting mix is low in nutrients
When an established berry patch has a documented nutrient shortage during its growing season
When berry plants resume growth after pruning or renovation and need replenishment based on crop guidance
When frequent watering in a raised bed or pot has depleted nutrients and testing supports feeding

Blueberries require acidic soil and often need a different nutrient plan from other berries; do not use this product as a substitute for correcting soil pH.

Results you can see

Feeds foliage for deeper color and a brighter, more lively look.

Encourages fresh leaf and stem growth for a fuller, thriving plant.

Supports healthy, resilient roots that absorb nutrients more effectively.

Works for berry bushes and canes

Blueberries
Raspberries
Blackberries
Strawberries
Currants
Gooseberries
Elderberries
Boysenberries

How to use

Watering can

2 Tbs (30 mL) per gallon of water

Spring & summer: every 1–2 weeks · Fall & winter: every 4 weeks
Hose end sprayer

Set dial to 1 oz (30mL) setting

Apply every 1-2 weeks in spring and summer
Leaf misting (optional)

1 tsp per quart (32 oz) of water

Spray on leaves every 1-2 weeks

What's inside

A 3.6-3-5.1 ratio weighted for fruit on a plant that also has to grow its own replacement. Potassium leads at 5.1%, moving sugars into ripening berries and managing the water pressure that keeps them plump — the nutrient that separates full, sweet fruit from small and seedy. Nitrogen at 3.6% — all nitrate, the form roots absorb directly with low burn risk — feeds this year's new canes, which are next year's harvest, without pushing so much leaf that fruiting suffers. Phosphate at 3% supports flowering and the shallow, spreading root systems brambles run.

Beyond NPK: sea kelp (Ascophyllum nodosum) for natural growth compounds, plus calcium at an unusually high 2.1% and 0.75% magnesium, with iron, manganese, zinc, boron, and copper. Calcium and boron are the two berry patches run short of first — calcium shortage shows as soft fruit that molds fast after picking, and low boron causes crumbly berries with missing drupelets that fall apart in your hand.

Label facts

NPK 3.6-3-5.1 with 2.1% calcium and 0.75% magnesium, plus iron, manganese, zinc, boron and copper.

Derived from kelp (ascophyllum nodosum), potassium phosphate, potassium nitrate, calcium nitrate, magnesium nitrate, boric acid, copper sulfate, ferric sulfate, manganese sulfate, zinc sulfate.

One 8 oz bottle makes 8 gallons of feed at 2 Tbs per gallon — the 32 oz makes 32.

Store cool and dark. Guaranteed 12 months from purchase; keeps up to 2 years.

Frequently asked questions

How often should I feed berry plants?

Berry Fertilizer is built for steady feeding through the season: 2 tablespoons per gallon of water every 1–2 weeks in spring and summer, dropping to every 4 weeks in fall and winter. A hose-end sprayer on the 1-ounce setting covers rows quickly, and you can mist the leaves with 1 teaspoon per quart every 1–2 weeks if you like. Water the whole patch rather than just the crowns, because bramble roots run well beyond your canes you can see.

Does this work on blueberries?

It supplies the nutrients blueberries use, but blueberries have a requirement no fertilizer can meet on its own: strongly acidic soil, around pH 4.5 to 5.5. Without it, their roots can’t absorb iron no matter what you feed. If your blueberries are yellowing in neutral soil, correct the pH with an acidifier first, or choose a blueberry-specific formula. For raspberries, blackberries and strawberries, Berry Fertilizer works as it is, with no soil caveat.

Why are my raspberries crumbly and falling apart?

Crumbly berries, fruit with missing or shriveled drupelets, usually trace to poor pollination, a boron shortage or virus. Cool, wet weather at bloom keeps bees off the flowers, and only better weather fixes that. Berry Fertilizer covers the boron side: the formula carries boron along with calcium, the two nutrients berry patches run short of first. If crumbliness persists season after season on the same canes, suspect virus and replace those plants with certified stock, since infected canes don’t recover.

Why did my canes grow huge but produce no fruit?

Usually it’s the bramble life cycle rather than a nutrient problem. Most raspberries and blackberries fruit on second-year canes: a first-year cane grows tall and leafy, then fruits the following summer. If every cane is cut to the ground each winter, the crop goes with it. Prune only the canes that have finished fruiting. Berry Fertilizer keeps nitrogen moderate so new canes grow without excess leaf; heavy nitrogen from lawn fertilizer drifting into the patch pushes the leafy effect further.

Should I feed berries after harvest?

Yes. Late summer and fall feeding matters for brambles, because next year’s fruiting canes and buds are developing right after this year’s harvest, and Berry Fertilizer is formulated to feed a plant that has to grow its own replacement. Keep the regular schedule through late summer, then move to the every-4-weeks fall rate as growth slows. Ease off heavy feeding ahead of hard frost so new growth has time to harden before winter.

When will I see results?

Quickly on the foliage. All of the nitrogen in Berry Fertilizer is nitrate, which roots absorb directly, so it starts working with the first watering; expect greener leaves and stronger cane growth within 1–2 weeks. Fruit responds on the next flush that sizes under regular feeding, roughly 3–5 weeks for fall-bearing raspberries in season. For summer-bearers fed after harvest, the return comes with next year’s crop, carried on your canes you’re feeding now.

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