An apple tree that bears fruit every year — without alternate bearing. Fruits that are deep red, intensely fragrant, and packed with 14 to 18 °Brix of quercetin and phloridzin. A tree that needs only half as many sprays as its neighbor. And one that, after three treatments with Grünkraft Calcium, bears fruits that are more uniform, aromatic, and storable than ever before.
This is not wishful thinking. These are measured results from our European field studies.
And the beauty of it: The principle behind it doesn't just apply to apple trees. It applies to every fruit tree — pear, cherry, plum, quince, apricot. Wherever a tree bears fruits that should contain polyphenols, vitamins, and secondary plant compounds, the work begins in the soil and with foliar fertilization.
The Problem — Why Apple Trees Need So Much Plant Protection
Apple scab is one of the most common apple tree diseases worldwide and the main pest in apple cultivation in Austria. The fungus Venturia inaequalis likes humid conditions — in wet years, the pressure explodes. And it preferentially attacks stressed trees.
Herein lies the key. A stressed tree — calcium deficiency, poor soil life, depleted soil — cannot maintain its own immune defense. Its cell walls are thin, its stomata are poorly regulated, its polyphenol production is restricted.
Organic fruit growers use sulfur products, baking soda, and acidic clay against scab, in addition to copper. Unlike synthetic fungicides that penetrate the plant, these active ingredients remain on the surface. However, they are washed off by rain and must be reapplied regularly.
This means: The conventional way is a cycle. The tree is weakened — so it is sprayed — the spraying stresses the soil — the soil nourishes the tree less well — the tree becomes weaker — so it is sprayed more.
The other way starts with the soil and the tree itself.
The Most Common Apple Diseases and Pests — What's Behind Them
Apple Scab — Venturia inaequalis: Dull olive-green, later blackish spots on leaves and fruits. Star-shaped cracks on the fruit. The fungus loves moisture and warm temperatures. First affects stressed, calcium-deficient trees.
Powdery Mildew — Podosphaera leucotricha: Whitish coating on young leaves and shoots. Typically in dry weather and high humidity. Vital trees with stable cell walls are significantly more resistant.
Fire Blight — Erwinia amylovora: The most feared bacterial disease in fruit growing. Affected shoots and blossoms look as if they have been burned. Spreads rapidly in warm, humid periods. Primarily affects lushly grown, over-fertilized shoots — a well-balanced mineralized tree is less susceptible.
Codling Moth — Cydia pomonella: The caterpillar of the small butterfly penetrates the fruits and destroys the core. In the so-called confusion method, pheromones are hung on dispensers in the apple orchard to attract males so that they cannot find the females. This method also works in home gardens.
Woolly Apple Aphid — Eriosoma lanigerum: Sucks on bark and shoots, leaving characteristic white, woolly webs. Prefers trees with low Brix values — the same principle as with all sucking insects.
Spider Mites: Especially in hot summers. Suck out leaf contents — leaves turn bronze. Vital trees with the physical protective film of GRÜNKRAFT Zeolith Pur on the leaves are significantly less affected.
The Program — How to Make an Apple Tree Vital
Step 1 — Soil Preparation: BODENKRAFT PUR + Steinkraft Basalt
Timing: In autumn or early spring — before budding.
BODENKRAFT PUR is tribomechanically ground zeolite with an intact crystal lattice structure. Particularly important for apple trees: It retains calcium and potassium in the root zone — precisely the two minerals that control polyphenols and secondary plant compounds in the fruit. And it buffers water fluctuations — drought stress is one of the main triggers for weak scab defense.
Steinkraft Basalt, with its paramagnetic properties, provides the broad spectrum of trace elements that an apple tree needs over decades — silicon for cell wall stability, iron, manganese, copper, zinc. The paramagnetic effect triples the microbial environment in the soil — and active soil life is the best long-term prevention against fungal diseases.
Application in the operation: Incorporate 300–400 kg/ha + Steinkraft Basalt 300–500 kg/ha into the soil. For older, depleted plantations, up to 1,000 kg of basalt in the first year.
In the garden: Lightly rake in a generous shovel of BODENKRAFT PUR and a shovel of Basalt Granulat around the base of each apple tree — in the area of the crown projection. Once a year in autumn or spring.
Step 2 — Activate Soil Life: AM+PLUS Microorganisms
Timing: In spring at budding — and then every 3 to 4 weeks.
AM+PLUS is the original solution made from Austrian organic herbs, based on lactic acid bacteria, refined with homeopathy and spagyrics. Particularly important for apple trees: The microorganisms in AM+PLUS compete with scab spores and other fungal pathogens for the same niches on the soil and leaf surface. An active, diverse soil microbiome protects the tree from below.
Customers also report: With the combination of basalt, zeolite, and AM+PLUS, slugs disappear from the garden. And soil life visibly regenerates — earthworms return, the soil becomes looser.
Application: As a soil drench around the tree in spring, then every 3 to 4 weeks. Also as a foliar spray on leaves and fruits.
Step 3 — Foliar Fertilization: GRÜNKRAFT Calcium from Bud Burst
Timing: At the first green — before flowering. This is the crucial moment.
GRÜNKRAFT Calcium is tribomechanically pulverized calcite with natural zeolite in a grain size of less than 8 µm. Stomata-permeable — the particles penetrate through the leaf pores and decompose into CO₂ for photosynthesis and calcium for the cell walls.
For apple trees, this works on three levels simultaneously:
First, calcium directly strengthens the cell walls — thin-walled cells are the entry point for scab fungi. More stable cells mean fewer infection points.
Second, calcium regulates the stomata — closed or well-regulated leaf pores absorb fewer fungal spores.
Third, CO₂ supply intensifies photosynthesis — and more photosynthesis means more quercetin, more phloridzin, more chlorogenic acid in the fruit. The Brix value increases. The polyphenols increase.
In European field studies with activated calcite: Treated apple trees had more uniform fruits, earlier ripening, higher dry matter content — and the need for protective agents could be halved in some cases.
GRÜNKRAFT Calcium can be easily combined with all commercially available plant protection products and fertilizers — which significantly simplifies the spraying program.
First application at bud burst: 5g per 1 liter of water. From the second application every 10-14 days: 20-30g per 1 liter of water. Spray time: Early morning or late afternoon when the stomata are open.
Step 4 — GRÜNKRAFT Zeolith Pur as a Physical Protective Film
Timing: Parallel to GRÜNKRAFT Calcium — from the first green.
GRÜNKRAFT Zeolith Pur forms a physical protective film on the leaf surface. The ultrafine silicate particles act as a natural repellent against spider mites, aphids, and woolly apple aphids — through a purely physical process. At the same time, it introduces silicon into the leaf, which strengthens the cell walls against fungal diseases.
Re-spray immediately after heavy rain — the protective film is washed off and needs to be renewed. Organic fruit growers do the exact same thing with copper and sulfur — only GRÜNKRAFT Zeolith Pur does not leave heavy metal contamination in the soil.
The Treatment Schedule for Apple Trees
Autumn or early spring: Work BODENKRAFT PUR + Steinkraft Basalt into the soil around the tree.
Bud burst — first treatment: GRÜNKRAFT Calcium 5g/l + AM+PLUS as a soil drench.
Before flowering — critical phase!: GRÜNKRAFT Calcium 20-30g/l + GRÜNKRAFT Zeolith Pur. The fruit quality for the entire year is decided during flowering.
After flowering, every 10-14 days: GRÜNKRAFT Calcium 20-30g/l + GRÜNKRAFT Zeolith Pur.
Fruit development: Continue treatment — polyphenols build up in the fruit until full ripeness. Each treatment increases the Brix value and nutrient density.
Every 3-4 weeks: AM+PLUS as a soil drench or foliar spray.
After rain: Reapply GRÜNKRAFT Zeolith Pur immediately.
For the Garden — One Tree, Made Simple
An apple tree in the garden is a gift for decades. Here's the simplified plan:
In autumn or spring, around the tree: Lightly rake in one shovel of BODENKRAFT PUR and one shovel of Basalt Granulat. This will remain active in the soil for years.
At the first green in spring: Add AM+PLUS to the watering can and water around the tree. Then repeat every 3 to 4 weeks.
From bud burst every 10-14 days: Use a spray bottle or garden sprayer with GRÜNKRAFT Calcium — 20-30g per 1 liter of water. Spray the entire tree — top and bottom of leaves, young shoots, and when fruits set, the fruits themselves.
GRÜNKRAFT Zeolith Pur in parallel — especially if powdery mildew or mites are a threat.
After rain: Re-spray immediately. This is the only effort that truly matters.
What you will observe over the years: The fruits become more uniform. The scent becomes more intense. The storability increases — an apple with 18 °Brix lasts significantly longer in the cellar than one with 8 °Brix. And alternate bearing — the yearly interruption of the harvest — becomes less frequent. A vitally nourished apple tree bears fruit every year.
And This Applies to All Fruit Trees
The principle is always the same — whether apple, pear, cherry, plum, apricot, quince, or grapevine.
All fruit trees need calcium for stable cell walls and disease resistance. All benefit from an active soil microbiome that makes minerals available. All produce more secondary plant compounds — more polyphenols, more anthocyanins, more aromatic substances — when they intensely photosynthesize. And all show the effect in the Brix value of the fruits.
The dosages remain the same. The timing adapts to the respective crop — start at bud burst, repeat every 10-14 days, react immediately to stress.
What changes is the initial situation of each crop — cherries react differently to moisture than plums, apricots have different fungal diseases than apples. But the core remains: A vital plant from healthy soil needs less external protection because it protects itself.
This is regenerative fruit culture. This is the way back to the true apple — the apple that truly justifies "an apple a day keeps the doctor away."
The Complete Program at a Glance
| Phase | Measure | Product | Timing |
|---|---|---|---|
| Autumn/Spring | Activate soil | BODENKRAFT PUR + Steinkraft Basalt | Once annually |
| Budding | Start soil life | AM+PLUS | At first green |
| Bud burst | First foliar fertilization | GRÜNKRAFT Calcium 5g/l | Immediately |
| Before flowering | Intensive treatment | GRÜNKRAFT Calcium 20-30g/l + GRÜNKRAFT Zeolith Pur | Every 10-14 days |
| Fruit development | Continue treatment | GRÜNKRAFT Calcium 20-30g/l + GRÜNKRAFT Zeolith Pur | Every 10-14 days |
| After rain | Renew protective film | GRÜNKRAFT Zeolith Pur | Immediately |
| Entire season | Maintain soil life | AM+PLUS | Every 3-4 weeks |
Links — all products and further knowledge
All products for the garden in our garden collection.
For fruit farms, all products in the agriculture collection.
What quercetin, phloridzin and pectin are — and why old apple varieties have six times more polyphenols — in the apple nutrient article.
Why paramagnetic basalt triples soil life — basalt blog article.
Properly using zeolite in the garden — the comprehensive guide.
Measuring the Brix value — instructions and Reams table — Brix article.
Why food today has fewer nutrients — article on minerals and damaged soils.
Sources: Land schafft Leben, Apple soil care plant protection | Schrot & Korn, Apples organic spraying differently 2022 | hausgarten.net, Combating apple scab | Oekomineral Group / Tribo Technologies, Field studies Apple Megagreen/Plantos Verde 2011–2014 — Yield increase up to 50%, reduced need for pesticides, improved dry matter content | steinkraft-naturerocks.com, Product information GRÜNKRAFT Calcium, GRÜNKRAFT Zeolith Pur, BODENKRAFT PUR, AM+PLUS | Philip S. Callahan, Paramagnetism — Rediscovering Nature's Secret Force of Growth
